JP6466676B2 - Visible light responsive photocatalyst complex and method for producing visible light responsive photocatalyst complex - Google Patents
Visible light responsive photocatalyst complex and method for producing visible light responsive photocatalyst complex Download PDFInfo
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- 239000011941 photocatalyst Substances 0.000 title claims description 98
- 238000004519 manufacturing process Methods 0.000 title claims description 37
- 239000001506 calcium phosphate Substances 0.000 claims description 116
- 235000011010 calcium phosphates Nutrition 0.000 claims description 116
- QORWJWZARLRLPR-UHFFFAOYSA-H tricalcium bis(phosphate) Chemical compound [Ca+2].[Ca+2].[Ca+2].[O-]P([O-])([O-])=O.[O-]P([O-])([O-])=O QORWJWZARLRLPR-UHFFFAOYSA-H 0.000 claims description 116
- 229910000389 calcium phosphate Inorganic materials 0.000 claims description 109
- 239000003463 adsorbent Substances 0.000 claims description 91
- FJOLTQXXWSRAIX-UHFFFAOYSA-K silver phosphate Chemical compound [Ag+].[Ag+].[Ag+].[O-]P([O-])([O-])=O FJOLTQXXWSRAIX-UHFFFAOYSA-K 0.000 claims description 86
- 229940019931 silver phosphate Drugs 0.000 claims description 86
- 229910000161 silver phosphate Inorganic materials 0.000 claims description 86
- SQGYOTSLMSWVJD-UHFFFAOYSA-N silver(1+) nitrate Chemical compound [Ag+].[O-]N(=O)=O SQGYOTSLMSWVJD-UHFFFAOYSA-N 0.000 claims description 56
- 239000002131 composite material Substances 0.000 claims description 38
- VTYYLEPIZMXCLO-UHFFFAOYSA-L Calcium carbonate Chemical compound [Ca+2].[O-]C([O-])=O VTYYLEPIZMXCLO-UHFFFAOYSA-L 0.000 claims description 36
- NBIIXXVUZAFLBC-UHFFFAOYSA-N Phosphoric acid Chemical compound OP(O)(O)=O NBIIXXVUZAFLBC-UHFFFAOYSA-N 0.000 claims description 35
- 230000001699 photocatalysis Effects 0.000 claims description 34
- 239000007864 aqueous solution Substances 0.000 claims description 33
- 229910001961 silver nitrate Inorganic materials 0.000 claims description 28
- 239000000243 solution Substances 0.000 claims description 21
- 229910021645 metal ion Inorganic materials 0.000 claims description 20
- 229910000147 aluminium phosphate Inorganic materials 0.000 claims description 18
- 238000000034 method Methods 0.000 claims description 17
- 229910000019 calcium carbonate Inorganic materials 0.000 claims description 14
- 239000002245 particle Substances 0.000 claims description 14
- 229940043430 calcium compound Drugs 0.000 claims description 12
- 150000001674 calcium compounds Chemical class 0.000 claims description 12
- 239000013078 crystal Substances 0.000 claims description 12
- 230000004298 light response Effects 0.000 claims description 12
- 238000001035 drying Methods 0.000 claims description 9
- 239000002904 solvent Substances 0.000 claims description 9
- OYPRJOBELJOOCE-UHFFFAOYSA-N Calcium Chemical compound [Ca] OYPRJOBELJOOCE-UHFFFAOYSA-N 0.000 claims description 6
- 239000011575 calcium Substances 0.000 claims description 6
- 229910052791 calcium Inorganic materials 0.000 claims description 6
- FUFJGUQYACFECW-UHFFFAOYSA-L calcium hydrogenphosphate Chemical compound [Ca+2].OP([O-])([O-])=O FUFJGUQYACFECW-UHFFFAOYSA-L 0.000 claims description 6
- 235000019700 dicalcium phosphate Nutrition 0.000 claims description 6
- 230000004931 aggregating effect Effects 0.000 claims description 5
- 229910021532 Calcite Inorganic materials 0.000 claims description 4
- OAICVXFJPJFONN-UHFFFAOYSA-N Phosphorus Chemical compound [P] OAICVXFJPJFONN-UHFFFAOYSA-N 0.000 claims description 4
- 229910052698 phosphorus Inorganic materials 0.000 claims description 4
- 239000011574 phosphorus Substances 0.000 claims description 4
- 239000011800 void material Substances 0.000 claims description 4
- 238000001914 filtration Methods 0.000 claims description 3
- 238000001179 sorption measurement Methods 0.000 description 46
- QGZKDVFQNNGYKY-UHFFFAOYSA-N Ammonia Chemical compound N QGZKDVFQNNGYKY-UHFFFAOYSA-N 0.000 description 42
- QTBSBXVTEAMEQO-UHFFFAOYSA-N Acetic acid Chemical compound CC(O)=O QTBSBXVTEAMEQO-UHFFFAOYSA-N 0.000 description 30
- 239000000843 powder Substances 0.000 description 23
- 229910021529 ammonia Inorganic materials 0.000 description 20
- 230000000052 comparative effect Effects 0.000 description 16
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 16
- RWSOTUBLDIXVET-UHFFFAOYSA-N Dihydrogen sulfide Chemical compound S RWSOTUBLDIXVET-UHFFFAOYSA-N 0.000 description 15
- 239000007789 gas Substances 0.000 description 15
- 239000000463 material Substances 0.000 description 15
- 229910000037 hydrogen sulfide Inorganic materials 0.000 description 14
- 238000000354 decomposition reaction Methods 0.000 description 9
- XYJRXVWERLGGKC-UHFFFAOYSA-D pentacalcium;hydroxide;triphosphate Chemical compound [OH-].[Ca+2].[Ca+2].[Ca+2].[Ca+2].[Ca+2].[O-]P([O-])([O-])=O.[O-]P([O-])([O-])=O.[O-]P([O-])([O-])=O XYJRXVWERLGGKC-UHFFFAOYSA-D 0.000 description 9
- 239000000126 substance Substances 0.000 description 9
- 238000000635 electron micrograph Methods 0.000 description 8
- 229910052588 hydroxylapatite Inorganic materials 0.000 description 8
- 230000008569 process Effects 0.000 description 8
- 239000002994 raw material Substances 0.000 description 8
- JPVYNHNXODAKFH-UHFFFAOYSA-N Cu2+ Chemical compound [Cu+2] JPVYNHNXODAKFH-UHFFFAOYSA-N 0.000 description 6
- 229910001431 copper ion Inorganic materials 0.000 description 6
- 239000012153 distilled water Substances 0.000 description 6
- 238000002441 X-ray diffraction Methods 0.000 description 5
- NBIIXXVUZAFLBC-UHFFFAOYSA-K phosphate Chemical compound [O-]P([O-])([O-])=O NBIIXXVUZAFLBC-UHFFFAOYSA-K 0.000 description 5
- 229910052709 silver Inorganic materials 0.000 description 5
- VHUUQVKOLVNVRT-UHFFFAOYSA-N Ammonium hydroxide Chemical compound [NH4+].[OH-] VHUUQVKOLVNVRT-UHFFFAOYSA-N 0.000 description 4
- RYGMFSIKBFXOCR-UHFFFAOYSA-N Copper Chemical compound [Cu] RYGMFSIKBFXOCR-UHFFFAOYSA-N 0.000 description 4
- 235000011114 ammonium hydroxide Nutrition 0.000 description 4
- 229910052802 copper Inorganic materials 0.000 description 4
- 239000010949 copper Substances 0.000 description 4
- 239000011521 glass Substances 0.000 description 4
- 239000002105 nanoparticle Substances 0.000 description 4
- 239000004332 silver Substances 0.000 description 4
- -1 silver ions Chemical class 0.000 description 4
- 239000011248 coating agent Substances 0.000 description 3
- 238000000576 coating method Methods 0.000 description 3
- 239000006185 dispersion Substances 0.000 description 3
- 230000000694 effects Effects 0.000 description 3
- 238000012986 modification Methods 0.000 description 3
- 230000004048 modification Effects 0.000 description 3
- 239000002002 slurry Substances 0.000 description 3
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 description 2
- PXHVJJICTQNCMI-UHFFFAOYSA-N Nickel Chemical compound [Ni] PXHVJJICTQNCMI-UHFFFAOYSA-N 0.000 description 2
- GWEVSGVZZGPLCZ-UHFFFAOYSA-N Titan oxide Chemical compound O=[Ti]=O GWEVSGVZZGPLCZ-UHFFFAOYSA-N 0.000 description 2
- PTFCDOFLOPIGGS-UHFFFAOYSA-N Zinc dication Chemical compound [Zn+2] PTFCDOFLOPIGGS-UHFFFAOYSA-N 0.000 description 2
- 230000002776 aggregation Effects 0.000 description 2
- 238000004220 aggregation Methods 0.000 description 2
- 238000004458 analytical method Methods 0.000 description 2
- 238000010668 complexation reaction Methods 0.000 description 2
- 238000004993 emission spectroscopy Methods 0.000 description 2
- 230000036571 hydration Effects 0.000 description 2
- 238000006703 hydration reaction Methods 0.000 description 2
- 229910052751 metal Inorganic materials 0.000 description 2
- 239000002184 metal Substances 0.000 description 2
- 238000002156 mixing Methods 0.000 description 2
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- 238000006722 reduction reaction Methods 0.000 description 2
- 238000003756 stirring Methods 0.000 description 2
- 238000004448 titration Methods 0.000 description 2
- ONDPHDOFVYQSGI-UHFFFAOYSA-N zinc nitrate Chemical compound [Zn+2].[O-][N+]([O-])=O.[O-][N+]([O-])=O ONDPHDOFVYQSGI-UHFFFAOYSA-N 0.000 description 2
- 101710134784 Agnoprotein Proteins 0.000 description 1
- LFQSCWFLJHTTHZ-UHFFFAOYSA-N Ethanol Chemical compound CCO LFQSCWFLJHTTHZ-UHFFFAOYSA-N 0.000 description 1
- 241000233866 Fungi Species 0.000 description 1
- 229910019142 PO4 Inorganic materials 0.000 description 1
- 241000490567 Pinctada Species 0.000 description 1
- BQCADISMDOOEFD-UHFFFAOYSA-N Silver Chemical compound [Ag] BQCADISMDOOEFD-UHFFFAOYSA-N 0.000 description 1
- FOIXSVOLVBLSDH-UHFFFAOYSA-N Silver ion Chemical compound [Ag+] FOIXSVOLVBLSDH-UHFFFAOYSA-N 0.000 description 1
- 229910021536 Zeolite Inorganic materials 0.000 description 1
- HCHKCACWOHOZIP-UHFFFAOYSA-N Zinc Chemical compound [Zn] HCHKCACWOHOZIP-UHFFFAOYSA-N 0.000 description 1
- 125000000218 acetic acid group Chemical group C(C)(=O)* 0.000 description 1
- 230000015572 biosynthetic process Effects 0.000 description 1
- XAAHAAMILDNBPS-UHFFFAOYSA-L calcium hydrogenphosphate dihydrate Chemical compound O.O.[Ca+2].OP([O-])([O-])=O XAAHAAMILDNBPS-UHFFFAOYSA-L 0.000 description 1
- 229910017052 cobalt Inorganic materials 0.000 description 1
- 239000010941 cobalt Substances 0.000 description 1
- GUTLYIVDDKVIGB-UHFFFAOYSA-N cobalt atom Chemical compound [Co] GUTLYIVDDKVIGB-UHFFFAOYSA-N 0.000 description 1
- 150000001875 compounds Chemical class 0.000 description 1
- 238000010276 construction Methods 0.000 description 1
- XTVVROIMIGLXTD-UHFFFAOYSA-N copper(II) nitrate Chemical compound [Cu+2].[O-][N+]([O-])=O.[O-][N+]([O-])=O XTVVROIMIGLXTD-UHFFFAOYSA-N 0.000 description 1
- NEFBYIFKOOEVPA-UHFFFAOYSA-K dicalcium phosphate Chemical compound [Ca+2].[Ca+2].[O-]P([O-])([O-])=O NEFBYIFKOOEVPA-UHFFFAOYSA-K 0.000 description 1
- 150000002013 dioxins Chemical class 0.000 description 1
- HNPSIPDUKPIQMN-UHFFFAOYSA-N dioxosilane;oxo(oxoalumanyloxy)alumane Chemical compound O=[Si]=O.O=[Al]O[Al]=O HNPSIPDUKPIQMN-UHFFFAOYSA-N 0.000 description 1
- 238000009826 distribution Methods 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 230000007613 environmental effect Effects 0.000 description 1
- 239000003344 environmental pollutant Substances 0.000 description 1
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- 230000036541 health Effects 0.000 description 1
- 230000003054 hormonal effect Effects 0.000 description 1
- 229910052500 inorganic mineral Inorganic materials 0.000 description 1
- WPBNNNQJVZRUHP-UHFFFAOYSA-L manganese(2+);methyl n-[[2-(methoxycarbonylcarbamothioylamino)phenyl]carbamothioyl]carbamate;n-[2-(sulfidocarbothioylamino)ethyl]carbamodithioate Chemical compound [Mn+2].[S-]C(=S)NCCNC([S-])=S.COC(=O)NC(=S)NC1=CC=CC=C1NC(=S)NC(=O)OC WPBNNNQJVZRUHP-UHFFFAOYSA-L 0.000 description 1
- 238000001000 micrograph Methods 0.000 description 1
- 239000011707 mineral Substances 0.000 description 1
- 229910052759 nickel Inorganic materials 0.000 description 1
- 230000003647 oxidation Effects 0.000 description 1
- 238000007254 oxidation reaction Methods 0.000 description 1
- 230000002093 peripheral effect Effects 0.000 description 1
- 239000010452 phosphate Substances 0.000 description 1
- 235000021317 phosphate Nutrition 0.000 description 1
- 229940085991 phosphate ion Drugs 0.000 description 1
- 150000003016 phosphoric acids Chemical class 0.000 description 1
- 238000007146 photocatalysis Methods 0.000 description 1
- 238000006303 photolysis reaction Methods 0.000 description 1
- 230000015843 photosynthesis, light reaction Effects 0.000 description 1
- 239000006069 physical mixture Substances 0.000 description 1
- 239000000049 pigment Substances 0.000 description 1
- 231100000719 pollutant Toxicity 0.000 description 1
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- 230000004043 responsiveness Effects 0.000 description 1
- 239000007787 solid Substances 0.000 description 1
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- 150000003464 sulfur compounds Chemical class 0.000 description 1
- 238000003786 synthesis reaction Methods 0.000 description 1
- 230000002194 synthesizing effect Effects 0.000 description 1
- OGIDPMRJRNCKJF-UHFFFAOYSA-N titanium oxide Inorganic materials [Ti]=O OGIDPMRJRNCKJF-UHFFFAOYSA-N 0.000 description 1
- ZNOKGRXACCSDPY-UHFFFAOYSA-N tungsten trioxide Chemical compound O=[W](=O)=O ZNOKGRXACCSDPY-UHFFFAOYSA-N 0.000 description 1
- 239000002699 waste material Substances 0.000 description 1
- 239000010457 zeolite Substances 0.000 description 1
- 229910052725 zinc Inorganic materials 0.000 description 1
- 239000011701 zinc Substances 0.000 description 1
Description
本発明は、可視光の照射下において光触媒活性を発現する可視光応答型光触媒を吸着材に複合化させた可視光応答型光触媒複合体、及び可視光応答型光触媒複合体の製造方法に関する。 The present invention relates to a visible light responsive photocatalyst complex in which a visible light responsive photocatalyst that exhibits photocatalytic activity under irradiation of visible light is combined with an adsorbent, and a method for producing the visible light responsive photocatalyst complex.
近年では、ダイオキシン等の環境ホルモン物質、水中や大気中の菌類や悪臭物質、居住空間での健康被害の原因になっている有機化学物質等の汚染物質を素早く、かつ、安全に分解、除去する技術が求められている。光照射により当該汚染物質を酸化・還元反応等により分解、除去する光触媒は、安全面及び省エネルギーの観点からも注目され、開発が進められている。 In recent years, environmental hormonal substances such as dioxins, fungi and malodorous substances in water and air, and organic chemicals that cause health damage in living spaces are quickly and safely decomposed and removed. Technology is required. Photocatalysts that decompose and remove such pollutants by oxidation / reduction reactions, etc. by light irradiation have attracted attention and are being developed from the viewpoint of safety and energy saving.
特に、幅広い波長領域で光触媒作用を発現させるために、太陽光線の約６０％を占める可視光の波長領域で応答可能な可視光応答型光触媒が注目されている。可視光に応答する光触媒として、特許文献１には、酸化チタン（TiO2）に異種元素をドーピングしたもの、特許文献２には、レアメタルである酸化タングステン（WO3）を使用したもの、特許文献３には、常温下で容易に合成可能なリン酸銀を使用したものがそれぞれ開示されている。 In particular, a visible light responsive photocatalyst capable of responding in a visible light wavelength region, which occupies about 60% of sunlight, has attracted attention in order to develop a photocatalytic action in a wide wavelength region. As a photocatalyst that responds to visible light, Patent Document 1 includes a titanium oxide (TiO 2 ) doped with a different element, Patent Document 2 uses a rare metal tungsten oxide (WO 3 ), Patent Document No. 3 discloses those using silver phosphate that can be easily synthesized at room temperature.
しかし、これらの光触媒は、粒子径の小さなナノ粒子として使用されることが多く、粒子同士が凝集するために扱いづらく、かつ、可視光応答型光触媒としての分解活性が低下する上、かかる光触媒自身に吸着能がない欠点があった。また、光触媒単体で使用すると、光触媒を担持する基材を光分解で損傷させるので、その適用範囲が限られていた。 However, these photocatalysts are often used as nanoparticles having a small particle diameter, and are difficult to handle because the particles aggregate together. In addition, the photocatalyst itself has a reduced decomposition activity as a visible light responsive photocatalyst. Had the disadvantage of not adsorbing. Further, when the photocatalyst is used alone, the base material supporting the photocatalyst is damaged by photolysis, so that the application range is limited.
そこで、光触媒粒子の凝集抑制、基材損傷予防、及び吸着能付与のため、従来から吸着材と光触媒を複合化（一体化）させることが試みられてきた。例えば、非特許文献１には、ゼオライトと光触媒材料を複合させる手法、非特許文献２には、活性炭と光触媒材料を複合化させる手法がそれぞれ開示されている。また、特許文献４には、ハイドロキシアパタイト（リン酸カルシウム）とリン酸銀との複合体を硫黄系化合物の吸着材として使用する手法が開示されている。 Therefore, attempts have been made to combine (integrate) an adsorbent and a photocatalyst for the purpose of suppressing aggregation of photocatalyst particles, preventing damage to the base material, and imparting adsorption ability. For example, Non-Patent Document 1 discloses a method of combining zeolite and a photocatalytic material, and Non-Patent Document 2 discloses a method of combining activated carbon and a photocatalytic material. Patent Document 4 discloses a technique of using a complex of hydroxyapatite (calcium phosphate) and silver phosphate as an adsorbent for a sulfur compound.
可視光の波長領域で確実に光触媒活性を発現する上で、容易に合成可能であり、かつ、材料コストも含めて考慮すると、吸着材に複合化させる可視光応答型光触媒として、常温下で容易に合成可能なリン酸銀を使用することが好ましい。また、吸着材と光触媒の複合体を製造するためには、その製造容易性や材料コストを考慮した上で、当該複合体が物質吸着性能と可視光に対する光触媒性能を確実に発現することが好ましい。 In order to ensure photocatalytic activity in the visible light wavelength range, it can be easily synthesized, and considering the material cost, it can be easily used at room temperature as a visible light responsive photocatalyst complexed with an adsorbent. It is preferable to use silver phosphate that can be synthesized. Further, in order to produce a composite of an adsorbent and a photocatalyst, it is preferable that the composite exhibits the substance adsorption performance and the photocatalytic performance for visible light with certainty in consideration of the ease of production and material cost. .
特許文献１の光触媒は、紫外線の波長領域で光触媒活性を発現する酸化チタンに対して可視光応答性を持たせるように異種元素をドーピングしたものであるので、可視光応答の安定性とドーピングのコストが課題となる。また、特許文献２の光触媒は、レアメタルを主原料としているので、その材料コストが課題となる。さらに、特許文献３の光触媒は、リン酸銀を使用しているものの、粒子同士の凝集による可視光応答型光触媒としての分解活性の低下が課題となる。また、非特許文献１及び２の複合体は、吸着材と光触媒が異種材料であるため、吸着剤と光触媒の複合化工程が複雑である。さらに、特許文献４の複合体は、リン酸銀を含むものの、ハイドロキシアパタイトの結晶構造上、リン酸銀が凝集されるので、可視光に対する光触媒活性を維持した複合化の実現には、至っていない。 The photocatalyst of Patent Document 1 is doped with a different element so as to give visible light responsiveness to titanium oxide that exhibits photocatalytic activity in the wavelength region of ultraviolet rays. Cost is an issue. Moreover, since the photocatalyst of patent document 2 uses the rare metal as the main raw material, the material cost becomes a subject. Furthermore, although the photocatalyst of Patent Document 3 uses silver phosphate, a reduction in decomposition activity as a visible light responsive photocatalyst due to aggregation of particles becomes a problem. In the composites of Non-Patent Documents 1 and 2, since the adsorbent and the photocatalyst are different materials, the composite process of the adsorbent and the photocatalyst is complicated. Furthermore, although the composite of Patent Document 4 contains silver phosphate, silver phosphate is aggregated due to the crystal structure of hydroxyapatite, so that the composite that maintains the photocatalytic activity for visible light has not been realized. .
本発明は、上記課題に鑑みてなされたものであり、より低コストで優れた物質吸着性能と可視光応答型の光触媒性能を確実に併せ持つことの可能な、新規かつ改良された可視光応答型光触媒複合体、及び可視光応答型光触媒複合体の製造方法を提供することを目的とする。 The present invention has been made in view of the above-mentioned problems, and is a new and improved visible light responsive type capable of reliably having excellent material adsorption performance and visible light responsive photocatalytic performance at a lower cost. It aims at providing the manufacturing method of a photocatalyst complex and a visible light response type photocatalyst complex.
本発明の一態様は、可視光の波長領域で光触媒活性を発現する可視光応答型光触媒複合体であって、リン酸カルシウムからなる複数の薄片が空隙部を介して互いに凝集して生成される吸着材と、前記薄片の表面又は端部の何れかに分散状態に担持されるリン酸銀からなる可視光応答型光触媒と、を含むことを特徴とする。 One aspect of the present invention is a visible light responsive photocatalyst complex that exhibits photocatalytic activity in the wavelength region of visible light, and an adsorbent that is formed by aggregating a plurality of flakes made of calcium phosphate through a void. And a visible light responsive photocatalyst made of silver phosphate supported in a dispersed state on either the surface or the end of the flakes.
本発明の一態様によれば、可視光に対する光触媒活性を有するリン酸銀が凝集されずに高分散状態で吸着材に担持されて複合化されるので、可視光応答型光触媒としての高い光触媒性能を維持した上で、吸着材としての吸着性能を確保することができる。 According to one aspect of the present invention, since silver phosphate having photocatalytic activity for visible light is not aggregated but is supported by an adsorbent in a highly dispersed state and composited, high photocatalytic performance as a visible light responsive photocatalyst In addition, the adsorption performance as an adsorbent can be secured.
このとき、本発明の一態様では、前記リン酸カルシウムは、リン酸８カルシウム又はリン酸水素カルシウムの何れかであることとしてもよい。 At this time, in one embodiment of the present invention, the calcium phosphate may be either 8 calcium phosphate or calcium hydrogen phosphate.
このようにすれば、吸着材を構成するリン酸カルシウムが薄片状となることから、リン酸銀を担持し易くなる。 If it does in this way, since the calcium phosphate which comprises an adsorbent becomes a flake shape, it will become easy to carry | support silver phosphate.
また、本発明の一態様では、前記リン酸銀が粒子状に生成され、該リン酸銀の粒子が前記リン酸カルシウムの前記薄片の表面に担持されることとしてもよい。 In one embodiment of the present invention, the silver phosphate may be generated in the form of particles, and the silver phosphate particles may be supported on the surface of the flakes of the calcium phosphate.
このようにすれば、吸着材を構成するリン酸カルシウムの薄片の表面にリン酸銀の粒子が高分散状態で担持されるので、可視光応答型光触媒としての高い光触媒性能を維持した上で、吸着材としての吸着性能を確保することができる。 In this way, since the silver phosphate particles are supported in a highly dispersed state on the surface of the calcium phosphate flakes constituting the adsorbent, the adsorbent is maintained while maintaining high photocatalytic performance as a visible light responsive photocatalyst. As a result, the adsorption performance can be ensured.
また、本発明の一態様では、前記リン酸銀が薄片状に生成され、該リン酸銀の薄片が前記リン酸カルシウムの前記薄片の前記表面又は前記端部に担持されることとしてもよい。 Moreover, in one aspect of the present invention, the silver phosphate may be produced in a flake shape, and the silver phosphate flake may be carried on the surface or the end of the flake of the calcium phosphate.
このようにすれば、吸着材を構成するリン酸カルシウムの薄片間に有する空隙部を架橋するように、リン酸銀の薄片が高分散状態で担持されるので、可視光応答型光触媒としての高い光触媒性能を維持した上で、吸着材としての吸着性能を確保することができる。 In this way, since the silver phosphate flakes are supported in a highly dispersed state so as to bridge the voids between the calcium phosphate flakes constituting the adsorbent, high photocatalytic performance as a visible light responsive photocatalyst In addition, the adsorption performance as an adsorbent can be secured.
また、本発明の他の態様は、可視光応答型光触媒を吸着材に複合化させた可視光応答型光触媒複合体の製造方法であって、カルシウム化合物を分散させた溶媒に所定量のリン酸水溶液を滴下して複数のリン酸カルシウムの薄片を生成するリン酸カルシウム生成工程と、前記複数のリン酸カルシウムの薄片をろ過してから乾燥させて複数の薄片状の前記リン酸カルシウムが空隙部を介して凝集して構成される前記吸着材を生成する吸着材生成工程と、乾燥後の前記吸着材を硝酸銀水溶液に接触させて前記リン酸カルシウムの前記薄片にリン酸銀を担持させる接触工程と、を含むことを特徴とする。 Another aspect of the present invention is a method for producing a visible light responsive photocatalyst complex in which a visible light responsive photocatalyst is combined with an adsorbent, wherein a predetermined amount of phosphoric acid is dissolved in a solvent in which a calcium compound is dispersed. A calcium phosphate production step in which an aqueous solution is dropped to produce a plurality of calcium phosphate flakes , and the plurality of calcium phosphate flakes are filtered and then dried to form a plurality of flake-like calcium phosphates aggregated through voids. wherein the adsorbent generating step of generating an adsorbent that, characterized in that it comprises a and a contacting step of Ru by supporting silver phosphate in the flakes of the calcium phosphate the adsorbent is brought into contact with the aqueous silver nitrate solution after drying .
本発明の他の態様によれば、低コストで吸着能を有するリン酸カルシウムからなる吸着材を合成した後に、当該吸着材を硝酸銀水溶液と接触させる簡便な手法によって、可視光応答型の光触媒としての分解性能と吸着材としての吸着性能を有した複合体を容易に生成することができる。 According to another aspect of the present invention, after synthesizing an adsorbent composed of calcium phosphate having adsorption ability at low cost, decomposition as a visible light responsive photocatalyst is achieved by a simple method of bringing the adsorbent into contact with an aqueous silver nitrate solution. A composite having performance and adsorption performance as an adsorbent can be easily produced.
このとき、本発明の他の態様では、前記リン酸カルシウム生成工程において、前記リン酸水溶液の前記所定量として前記カルシウム化合物に含まれるカルシウムと前記リン酸に含まれるリンのモル比が０．５乃至１．３となるように該リン酸水溶液を滴下することとしてもよい。 At this time, in another aspect of the present invention, in the calcium phosphate producing step, the molar ratio of calcium contained in the calcium compound and phosphorus contained in the phosphoric acid is 0.5 to 1 as the predetermined amount of the phosphoric acid aqueous solution. It is good also as dropping this phosphoric acid aqueous solution so that it may become .3.
このようにすれば、溶媒中に分散させた炭酸カルシウムから複数の薄片状のリン酸カルシウムを凝集させて構成される吸着材を効率的に生成できる。 In this way, it is possible to efficiently generate an adsorbent constituted by aggregating a plurality of flaky calcium phosphates from calcium carbonate dispersed in a solvent.
また、本発明の他の態様では、前記接触工程で前記吸着材に接触させる前記硝酸銀水溶液の濃度は、７乃至５０ｍＭであることとしてもよい。 In another aspect of the present invention, the concentration of the silver nitrate aqueous solution brought into contact with the adsorbent in the contact step may be 7 to 50 mM.
このようにすれば、リン酸カルシウムの薄片の表面にリン酸銀が高分散状態で担持された複合体が確実に生成できる。 In this way, a complex in which silver phosphate is supported in a highly dispersed state on the surface of the calcium phosphate flakes can be reliably generated.
また、本発明の他の態様では、前記リン酸カルシウム生成工程後に金属イオン溶液を滴下する金属イオン滴下工程を更に含むこととしてもよい。 Moreover, in another aspect of the present invention, a metal ion dropping step of dropping a metal ion solution after the calcium phosphate generation step may be further included.
このようにすれば、アンモニアや硫化水素等の吸着対象となるガスの吸着力を高めた複合体を生成できる。 By doing so, it is possible to generate a composite with enhanced adsorption power of a gas to be adsorbed such as ammonia or hydrogen sulfide.
また、本発明の他の態様では、前記リン酸カルシウム生成工程では、前記炭酸カルシウムとしてアラゴナイト構造、カルサイト構造、又はバテライト構造の結晶構造の炭酸カルシウムを前記溶媒中に分散させることとしてもよい。 In another aspect of the present invention, in the calcium phosphate generating step, calcium carbonate having an aragonite structure, a calcite structure, or a crystal structure of a vaterite structure may be dispersed in the solvent as the calcium carbonate.
このようにすれば、複数の薄片状のリン酸カルシウムが空隙部を介して凝集した構成の吸着材が生成されるようになる。 In this way, an adsorbent having a configuration in which a plurality of flaky calcium phosphates are aggregated via the voids is generated.
以上説明したように、本発明によれば、より低コストで優れた物質吸着性能と可視光応答型の光触媒性能を確実に併せ持つ可視光応答型光触媒複合体を簡便な手法により、確実に生成することができる。 As described above, according to the present invention, a visible light responsive photocatalyst complex that reliably combines excellent substance adsorption performance and visible light responsive photocatalytic performance at a lower cost can be reliably generated by a simple method. be able to.
以下、本発明の好適な実施の形態について詳細に説明する。なお、以下に説明する本実施形態は、特許請求の範囲に記載された本発明の内容を不当に限定するものではなく、本実施形態で説明される構成の全てが本発明の解決手段として必須であるとは限らない。 Hereinafter, preferred embodiments of the present invention will be described in detail. The present embodiment described below does not unduly limit the contents of the present invention described in the claims, and all the configurations described in the present embodiment are essential as means for solving the present invention. Not necessarily.
図１は、本発明の一実施形態に係る可視光応答型光触媒複合体の一部を部分拡大した電子顕微鏡写真図である。本実施形態の可視光応答型光触媒複合体は、可視光応答型光触媒としてリン酸銀をリン酸カルシウムからなる吸着材に複合化させることによって、吸着材としての物質吸着性能に加えて、可視光の波長領域での光触媒活性を発現可能としたものである。 FIG. 1 is an electron micrograph of a partially enlarged view of a visible light responsive photocatalyst complex according to an embodiment of the present invention. The visible light responsive photocatalyst complex of the present embodiment is composed of silver phosphate as a visible light responsive photocatalyst and an adsorbent composed of calcium phosphate, in addition to the substance adsorption performance as an adsorbent, and the wavelength of visible light. The photocatalytic activity in the region can be expressed.
本実施形態の可視光応答型光触媒複合体に含まれる吸着材は、リン酸カルシウムからなる厚さ１００ｎｍ以下の複数の薄片が空隙部を介して互いに凝集して寄り集まって、所謂フラワー形状に生成されている。可視光応答型光触媒となるリン酸銀は、リン酸カルシウムの薄片の表面又は端部の何れかに分散状態に担持されて吸着材と複合化されている。本実施形態では、図１に示すように、ナノ粒子状のリン酸銀がリン酸カルシウムからなる薄片の表面や端部に点在するように分散された高分散状態で担持されて複合化されている。なお、ここで言及する「空隙部」とは、一のリン酸カルシウムの薄片の表面から他のリン酸カルシウムの薄片の表面との間の空間部分を示す。 The adsorbent contained in the visible light responsive photocatalyst complex of the present embodiment is produced in a so-called flower shape by a plurality of flakes made of calcium phosphate having a thickness of 100 nm or less aggregated and gathered together through a gap. Yes. Silver phosphate serving as a visible light responsive photocatalyst is supported in a dispersed state on either the surface or the end of a calcium phosphate flake and is combined with an adsorbent. In this embodiment, as shown in FIG. 1, nanoparticulate silver phosphate is supported and compounded in a highly dispersed state in which it is dispersed so as to be scattered on the surface and end of a thin piece made of calcium phosphate. . The “void” referred to here indicates a space portion between the surface of one calcium phosphate flake and the surface of another calcium phosphate flake.
また、本実施形態では、吸着材を構成するリン酸カルシウムとして、リン酸８カルシウム又はリン酸水素カルシウムの何れかを使用する。このため、リン酸カルシウムが薄片状となり、ナノ粒子状のリン酸銀を高分散状態に担持し易くなる。このように、吸着材を複数の薄片状のリン酸カルシウムが空隙部を介して互いに凝集した形状とすることによって、リン酸銀を凝集させずに高分散状態で担持できるので、水等に分散させても、リン酸カルシウムとリン酸銀が分離しない吸着・分解能を有する複合体となる。 In the present embodiment, either calcium calcium phosphate or calcium hydrogen phosphate is used as the calcium phosphate constituting the adsorbent. For this reason, calcium phosphate becomes flakes, and it becomes easy to carry nanoparticulate silver phosphate in a highly dispersed state. In this way, the adsorbent can be supported in a highly dispersed state without agglomerating silver phosphate by agglomerating a plurality of flaky calcium phosphates with each other through voids, so that it can be dispersed in water or the like. Also, it becomes a complex having adsorption and resolution in which calcium phosphate and silver phosphate are not separated.
なお、本実施形態では、ナノ粒子状のリン酸銀が薄片状のリン酸カルシウムの表面や端部に分散された状態で担持されて複合化されているが、リン酸カルシウムの薄片の一部をリン酸銀の薄片に転換させて、リン酸カルシウムとリン酸銀を複合化されてもよい。すなわち、リン酸カルシウムの薄片の表面又は端部の何れかにリン酸銀が高分散状態に担持されていれば、リン酸銀が薄片状に生成され、当該リン酸銀の薄片がリン酸カルシウムの薄片の表面又は端部に担持される構成としてもよい。 In this embodiment, nanoparticulate silver phosphate is supported and compounded in a state of being dispersed on the surface and edges of flaky calcium phosphate. However, a part of the calcium phosphate flake is silver phosphate. The calcium phosphate and silver phosphate may be combined to be converted into a thin piece. That is, if silver phosphate is supported in a highly dispersed state on either the surface or the edge of the calcium phosphate flakes, the silver phosphate is produced in the form of flakes, and the silver phosphate flakes are the surface of the calcium phosphate flakes Or it is good also as a structure carry | supported by an edge part.
このように、本実施形態では、リン酸銀が凝集されずにナノ粒子状又は薄片状に生成されて、リン酸カルシウムの薄片の表面又は端部の何れかに高分散状態に担持されることによって、リン酸銀の可視光に対する光触媒活性を発現できる。すなわち、本実施形態の複合体は、可視光に対する光触媒活性を有するリン酸銀が凝集されずに、高分散状態で吸着材に担持されて複合化されるので、可視光応答型の高い光触媒性能を維持した上で、吸着材としての吸着性能を確保することができる。また、本実施形態の可視光応答型光触媒複合体は、光触媒粒子を吸着材の表面又は端部の何れかに高分散状態で担持させているので、光触媒作用による基材損傷のリスクも低減される。 Thus, in this embodiment, silver phosphate is not aggregated and is produced in the form of nanoparticles or flakes, and is supported in a highly dispersed state on either the surface or the end of the calcium phosphate flakes, The photocatalytic activity of silver phosphate with respect to visible light can be expressed. That is, in the composite of this embodiment, the silver phosphate having photocatalytic activity with respect to visible light is not aggregated, but is supported by the adsorbent in a highly dispersed state and composited. In addition, the adsorption performance as an adsorbent can be secured. In addition, since the visible light responsive photocatalyst complex of this embodiment carries the photocatalyst particles in a highly dispersed state on either the surface or the end of the adsorbent, the risk of substrate damage due to photocatalysis is also reduced. The
本発明者は、前述した本発明の目的を達成するために鋭意検討を重ねた結果、国内に大量に産出するカルシウム化合物を原料にして、低コストで吸着能を有する薄片が寄り集まった所謂フラワー形状のリン酸カルシウムからなる吸着材を生成後に、当該吸着材を常温でAg水溶液と接触させるという非常に簡便な手法により、リン酸銀が凝集されずに高分散状態で吸着材に担持された吸着・分解能を有した複合体が得られることを見出した。本発明者は、かかる知見に基づき更に研究を行った結果、本発明を完成するに至った。 As a result of intensive studies in order to achieve the above-described object of the present invention, the present inventor has made a so-called flower in which flakes having absorptive capacity gathered at a low cost using a calcium compound produced in large quantities in Japan as a raw material. After generating an adsorbent composed of calcium phosphate in the shape, the adsorbent is supported on the adsorbent in a highly dispersed state without silver phosphate being aggregated by a very simple method of contacting the adsorbent with an aqueous Ag solution at room temperature. It has been found that a complex with resolution can be obtained. As a result of further research based on this knowledge, the present inventor has completed the present invention.
次に、本発明の一実施形態に係る可視光応答型光触媒複合体の製造方法について、図面を使用しながら説明する。図２は、本発明の一実施形態に係る可視光応答型光触媒複合体の製造方法の概略を示すフロー図である。 Next, a method for producing a visible light responsive photocatalyst complex according to an embodiment of the present invention will be described with reference to the drawings. FIG. 2 is a flowchart showing an outline of a method for producing a visible light responsive photocatalyst complex according to an embodiment of the present invention.
本実施形態に係る可視光応答型光触媒複合体の製造方法では、まず、カルシウム化合物として炭酸カルシウムを常温から８０℃の水又はアルコール等の溶媒に分散させる（分散工程Ｓ１１）。本実施形態では、吸着材となる薄片が寄り集まった所謂フラワー形状のリン酸カルシウムの原料として、薄片になり易い炭酸カルシウムを用いることが好ましい。また、複数の薄片状のリン酸カルシウムが空隙部を介して凝集した構成の吸着材を生成するために、分散工程Ｓ１１で分散させる炭酸カルシウムの結晶構造は、アラゴナイト構造、カルサイト構造、又はバテライト構造の何れでも良く、炭酸カルシウムは、重質、軽質、貝殻等の何れでも良い。 In the method for producing a visible light responsive photocatalyst complex according to the present embodiment, first, calcium carbonate as a calcium compound is dispersed in a solvent such as water or alcohol at room temperature to 80 ° C. (dispersing step S11). In this embodiment, it is preferable to use calcium carbonate that tends to become flakes as a raw material of so-called flower-shaped calcium phosphate in which flakes that become adsorbents gather. In addition, in order to generate an adsorbent having a structure in which a plurality of flaky calcium phosphates are aggregated via voids, the crystal structure of calcium carbonate dispersed in the dispersion step S11 is an aragonite structure, a calcite structure, or a vaterite structure. Any may be sufficient, and calcium carbonate may be any of heavy, light, and shells.
次に、炭酸カルシウムを分散させた溶媒に所定量のリン酸水溶液を滴下する（滴下工程Ｓ１２）。本実施形態では、溶媒中に分散させた炭酸カルシウムから複数の薄片状のリン酸カルシウムを凝集させて構成される吸着材を効率的に生成するために、滴下工程Ｓ１２において、リン酸水溶液の所定量として炭酸カルシウムに含まれるカルシウムとリン酸に含まれるリンのモル比が０．５乃至１．３となるようにリン酸水溶液を滴下する。このような濃度条件のリン酸水溶液を滴下することによって、吸着材を構成するリン酸カルシウムとして、薄片状のリン酸８カルシウム又はリン酸水素カルシウムの何れかが生成される。本実施形態では、このように分散工程Ｓ１１及び滴下工程Ｓ１２によって、カルシウム化合物を分散させた溶媒に所定量のリン酸水溶液を滴下してリン酸カルシウムが生成されるリン酸カルシウム生成工程が行われる。 Next, a predetermined amount of phosphoric acid aqueous solution is dropped into a solvent in which calcium carbonate is dispersed (dropping step S12). In the present embodiment, in order to efficiently generate an adsorbent constituted by aggregating a plurality of flaky calcium phosphates from calcium carbonate dispersed in a solvent, in the dropping step S12, a predetermined amount of the phosphoric acid aqueous solution is used. An aqueous phosphoric acid solution is dropped so that the molar ratio of calcium contained in calcium carbonate and phosphorus contained in phosphoric acid is 0.5 to 1.3. By dropping the phosphoric acid aqueous solution having such a concentration condition, either flaky 8 calcium phosphate or calcium hydrogen phosphate is produced as the calcium phosphate constituting the adsorbent. In this embodiment, the calcium phosphate production | generation process in which a predetermined amount of phosphoric acid aqueous solution is dripped at the solvent which disperse | distributed the calcium compound by this dispersion | distribution process S11 and dripping process S12 is produced | generated is performed.
その後、上記リン酸カルシウム生成工程（分散工程Ｓ１１及び滴下工程Ｓ１２）によって生成された複数のリン酸カルシウムの薄片をろ過してから、乾燥させて吸着材を生成する（吸着材生成工程Ｓ１３）。このように、リン酸水溶液を適量滴下させてからろ過及び乾燥するによって、リン酸カルシウムの薄片が空隙部を介して寄り集まった形状の吸着材が得られる。なお、滴下するリン酸量や温度により、様々なフラワー形状の吸着材の合成が可能である。 Thereafter, the plurality of calcium phosphate flakes produced in the calcium phosphate production step (dispersing step S11 and dropping step S12) are filtered and then dried to produce an adsorbent (adsorbent production step S13). In this way, an adsorbent having a shape in which flakes of calcium phosphate gather together through the voids by dropping a suitable amount of an aqueous phosphoric acid solution and then filtering and drying. Various flower-shaped adsorbents can be synthesized depending on the amount of phosphoric acid to be dropped and the temperature.
次に、乾燥後のリン酸カルシウムの薄片からなる吸着材をＡｇ水溶液に接触させる（接触工程Ｓ１４）。本実施形態では、吸着材に担持させるリン酸銀の生成に用いるＡｇ水溶液は、可溶性の硝酸銀水溶液が好ましい。また、リン酸カルシウムの薄片の表面にリン酸銀が高分散状態で担持された複合体が確実に生成するために、硝酸銀水溶液の濃度は、低い方が好ましい。 Next, the adsorbent made of the calcium phosphate flakes after drying is brought into contact with the aqueous Ag solution (contact step S14). In this embodiment, the Ag aqueous solution used for the production of silver phosphate supported on the adsorbent is preferably a soluble silver nitrate aqueous solution. Further, the concentration of the aqueous silver nitrate solution is preferably low in order to reliably produce a complex in which silver phosphate is supported in a highly dispersed state on the surface of the calcium phosphate flakes.
接触工程Ｓ１４において、硝酸銀水溶液の濃度が高いと、複数のリン酸カルシウムの薄片からなる吸着材の表面にリン酸銀が生成せずに、当該吸着材とリン酸銀がそれぞれ別々に生成してしまい複合体とならない。このため、リン酸カルシウムとリン酸銀との複合体を生成するために、硝酸銀水溶液を吸着材と接触させる場合には、当該硝酸銀水溶液は、低濃度が望ましく、具体的には、その濃度が７乃至５０ｍＭの範囲となる。 In the contact step S14, when the concentration of the aqueous silver nitrate solution is high, silver phosphate is not generated on the surface of the adsorbent composed of a plurality of calcium phosphate flakes, and the adsorbent and silver phosphate are generated separately and combined. It does not become a body. For this reason, when an aqueous silver nitrate solution is brought into contact with an adsorbent in order to produce a complex of calcium phosphate and silver phosphate, the aqueous silver nitrate solution preferably has a low concentration. The range is 50 mM.
このように、接触工程Ｓ１４で複数のリン酸カルシウムの薄片が空隙部を介して寄り集まった形状の吸着材を硝酸銀水溶液に接触させることによって、瞬時にリン酸カルシウムの薄片の表面や端部、周縁部にリン酸銀のナノ粒子が高分散状態で担持されるようになる。すなわち、本実施形態では、光触媒となるリン酸銀と複合化させる吸着材が複数の薄片からなるリン酸カルシウムを空隙部を介して凝集させた形状となっているので、リン酸銀を高分散状態に担持し易くなる。 In this way, by bringing the adsorbent having a shape in which a plurality of flakes of calcium phosphate gathered together through the voids in the contact step S14 into contact with the silver nitrate aqueous solution, the surface, the edge, and the peripheral portion of the calcium phosphate flakes are instantaneously bonded to the surface. Silver nanoparticles are supported in a highly dispersed state. That is, in this embodiment, since the adsorbent compounded with silver phosphate serving as a photocatalyst has a shape in which calcium phosphate composed of a plurality of flakes is aggregated through the voids, the silver phosphate is in a highly dispersed state. It becomes easy to carry.
なお、接触工程Ｓ１４において、リン酸カルシウムのリン酸イオンの配置により、銀イオンとの複合化が決まると考えられるので、吸着剤と硝酸銀水溶液を接触させる際には、リン酸カルシウムのリン酸イオンの位置が重要となる。すなわち、リン酸カルシウムのリン酸イオンの配置により硝酸銀水溶液に含まれる銀イオンとの複合化が決まる。また、リン酸銀を高分散状態で担持するためには、リン酸カルシウムの単位質量あたりの表面積の大きい方が硝酸銀に含まれる銀イオンとの反応性が向上するので、リン酸カルシウムの形状が薄片状の平坦な構造がよい。 In addition, in the contact step S14, it is considered that the complexation with the silver ions is determined by the arrangement of the phosphate ions of the calcium phosphate. Therefore, when the adsorbent is brought into contact with the silver nitrate aqueous solution, the position of the phosphate ions of the calcium phosphate is important. It becomes. That is, the arrangement of the phosphate ions of calcium phosphate determines the complexation with the silver ions contained in the aqueous silver nitrate solution. Also, in order to carry silver phosphate in a highly dispersed state, the larger the surface area per unit mass of calcium phosphate, the better the reactivity with silver ions contained in silver nitrate, so the shape of calcium phosphate is flat and flat. The structure is good.
特に、リン酸カルシウム１０が薄片状を呈するリン酸８カルシウム（ＯＣＰ）やリン酸水素カルシウム（鉱物名：Brushite ）の場合では、図３（Ａ）に示すように、結晶構造中に水和層１２を含むので、水和層をもたないハイドロキシアパタイトと比較して、その結晶構造が疎となる。このため、リン酸カルシウム１０の表面に有するリンＰは、各リン酸カルシウム１０の結晶間に介在している水和層１２の影響によって、ある程度分散されているので、粒子状のリン酸銀１４が高分散状態でリン酸カルシウム１０の表面に生成されると考えられる。 In particular, in the case of 8 calcium phosphate (OCP) or calcium hydrogen phosphate (mineral name: Brushite) in which the calcium phosphate 10 has a flake shape, the hydrated layer 12 is formed in the crystal structure as shown in FIG. As a result, the crystal structure is sparse compared to hydroxyapatite that does not have a hydrated layer. For this reason, the phosphorus P possessed on the surface of the calcium phosphate 10 is dispersed to some extent due to the influence of the hydration layer 12 interposed between the crystals of each calcium phosphate 10, so that the particulate silver phosphate 14 is in a highly dispersed state. It is thought that it is produced on the surface of calcium phosphate 10.
一方、ハイドロキシアパタイトは、図３（Ｂ）に示すように、水和層がなくリン酸カルシウム２０の結晶が密な構造となっているので、リン酸カルシウム２０の表面に有するリン同士が非常に近接している。このため、生成された粒子状のリン酸銀２４の結晶成長が促進されて、凝集化されたリン酸銀２４ａが粗大化されて塊状に生成されるので、リン酸カルシウム２０の表面に複合化できないと考えられる。このことからも、リン酸銀とリン酸カルシウムを複合化するためには、吸着材を構成するリン酸カルシウムが薄片状のリン酸８カルシウムやリン酸水素カルシウムで生成されることが好ましいことが分かる。 On the other hand, as shown in FIG. 3B, the hydroxyapatite has no hydration layer and has a dense structure of calcium phosphate 20 crystals, so that the phosphors on the surface of the calcium phosphate 20 are very close to each other. . For this reason, the crystal growth of the produced granular silver phosphate 24 is promoted, and the aggregated silver phosphate 24a is coarsened and formed into a lump, so that it cannot be combined with the surface of the calcium phosphate 20 Conceivable. This also shows that in order to combine silver phosphate and calcium phosphate, it is preferable that the calcium phosphate constituting the adsorbent is produced from flaky 8 calcium phosphate or calcium hydrogen phosphate.
接触工程Ｓ１４でリン酸カルシウムの薄片からなる吸着材を硝酸銀水溶液と接触してリン酸銀を担持させたら、その後は、不図示の水洗工程、ろ過工程、及び乾燥工程を経て、リン酸カルシウムとリン酸銀の複合体を得る。本実施形態では、可視光応答型の光触媒となるリン酸銀が凝集することなく、高分散状態でリン酸カルシウムからなる吸着材に担持されて複合化されるので、リン酸銀が可視光に対する光触媒活性を発現できるようになる。 After the adsorbent made of calcium phosphate flakes is brought into contact with the silver nitrate aqueous solution in the contact step S14 to carry the silver phosphate, the water phosphate step, the filtration step, and the drying step (not shown) are followed by the calcium phosphate and the silver phosphate. A complex is obtained. In this embodiment, silver phosphate that becomes a visible light responsive photocatalyst is agglomerated without being agglomerated and supported by an adsorbent made of calcium phosphate in a highly dispersed state, so that silver phosphate is photocatalytic activity for visible light. Can be expressed.
このように、本実施形態では、吸着材として、国内で大量に産出するカルシウム化合物を原料にした複数の薄片が空隙部を介して寄り集まった形状のリン酸カルシウムを選択した。また、可視光応答型光触媒として、常温下で容易に合成可能なリン酸銀を選択した。すなわち、吸着材と光触媒を共通のリン酸イオンを含む材質を使用して、吸着材となる複数の薄片が空隙部を介して寄り集まった形状のリン酸カルシウムに硝酸銀水溶液を接触させることによって、リン酸カルシウム薄片表面に可視光応答型光触媒であるリン酸銀のナノ粒子を高分散状態で担持させて、リン酸カルシウムとリン酸銀とを複合化させた。 As described above, in this embodiment, calcium phosphate having a shape in which a plurality of flakes made of calcium compounds produced in large quantities in Japan as a raw material gathered together through the voids is selected as the adsorbent. Further, silver phosphate that can be easily synthesized at room temperature was selected as the visible light responsive photocatalyst. That is, by using a material containing a common phosphate ion for the adsorbent and the photocatalyst, the calcium phosphate flakes are brought into contact with the calcium phosphate having a shape in which a plurality of flakes that are adsorbents gathered together through the voids. Nanoparticles of silver phosphate, which is a visible light responsive photocatalyst, were supported on the surface in a highly dispersed state, and calcium phosphate and silver phosphate were combined.
これによって、低コスト材料から物質吸着性能と可視光に対する光触媒活性を発現する分解能を有する複合体を効率よく生成することが実現された。すなわち、本実施形態の複合体を構成する吸着材は、国内に大量に産出するカルシウム化合物を原料にし、かつ、１００℃以下の低温条件下で短時間の合成により生成される。また、光触媒を吸着材に複合化する手法が常温で硝酸銀水溶液と吸着材を接触させる非常に簡便な手法により生成できる。 As a result, it has been realized that a complex having a resolution capable of exhibiting a substance adsorption performance and a photocatalytic activity for visible light can be efficiently generated from a low-cost material. That is, the adsorbent constituting the composite of the present embodiment is produced by synthesis in a short time under a low temperature condition of 100 ° C. or less using a calcium compound produced in large quantities in Japan as a raw material. Moreover, the method of combining the photocatalyst with the adsorbent can be generated by a very simple method of bringing the silver nitrate aqueous solution into contact with the adsorbent at room temperature.
このため、カルシウム化合物をフィラーや顔料等として用いている建築業界、紙業界、プラスチック業界等の幅広い業界へ適用可能であるので、本実施形態の可視光応答型光触媒複合体の製品高付加価値化が可能となる。具体的には、塗り壁に付着させる炭酸カルシウムの一部を当該複合体からなる粉末に置き換えることによって、吸着と分解を併せ持った塗り壁とすることができる。また、塗料原料としても利用可能である。さらに、複合体を構成する吸着材の原料をカルシウム化合物としているので、貝殻等のカルシウム系の廃棄物を当該複合体の生成用の材料資源として有効活用ができるようになる。 For this reason, it can be applied to a wide range of industries such as the construction industry, paper industry, and plastic industry that use calcium compounds as fillers and pigments. Is possible. Specifically, by replacing a part of calcium carbonate attached to the coating wall with the powder made of the composite, a coating wall having both adsorption and decomposition can be obtained. It can also be used as a coating material. Furthermore, since the raw material of the adsorbent constituting the composite is a calcium compound, calcium-based waste such as shells can be effectively used as a material resource for generating the composite.
なお、リン酸銀をリン酸カルシウムに担持させて複合化させる際に、アンモニアや硫化水素ガスの吸着能を向上させるために、吸着材を硝酸銀水溶液に接触させる前に金属イオンと接触させてもよい。すなわち、本発明の他の実施形態に係る可視光応答型光触媒複合体の製造方法では、図４に示すように、分散工程Ｓ２１及び滴下工程Ｓ２２からなるリン酸カルシウム生成工程後に、例えば、銅イオンを含む硝酸銅水溶液等の金属イオンを含む溶液を滴下する金属イオン滴下工程Ｓ２３を実施する。 In addition, when making silver phosphate carry | support on calcium phosphate and making it composite, in order to improve the adsorption capacity of ammonia and hydrogen sulfide gas, you may make it contact with a metal ion before making an adsorbent contact silver nitrate aqueous solution. That is, in the method for producing a visible light responsive photocatalyst complex according to another embodiment of the present invention, as shown in FIG. 4, for example, after the calcium phosphate production step including the dispersion step S <b> 21 and the dropping step S <b> 22, copper ions are included. A metal ion dropping step S23 for dropping a solution containing metal ions such as an aqueous copper nitrate solution is performed.
そして、金属イオン滴下工程Ｓ２３において、リン酸カルシウムに含まれるカルシウムの一部を銅に変えてから、乾燥工程Ｓ２４で吸着材を乾燥させたものを硝酸銀水溶液に接触させる（接触工程Ｓ２５）。このように、吸着材を硝酸銀水溶液に接触させる前に銅イオン等の金属イオンを含む溶液を滴下することによって、リン酸カルシウムに担持された金属イオンの影響により、アンモニア、硫化水素等のガスの吸着能が向上した複合体を生成できる。また、このように金属イオンを含む溶液を滴下することによってリン酸銀の粒子が小さくなるので、光触媒活性が向上するようになる。なお、銅イオン以外でも、亜鉛イオン、ニッケル、マンガン、コバルト等の他の金属イオンを含む溶液を滴下することによっても、リン酸カルシウムに担持された金属イオンの影響により、アンモニア、硫化水素等のガスの吸着能が向上した複合体を生成できる。 And in metal ion dripping process S23, after changing a part of calcium contained in calcium phosphate into copper, what dried the adsorbent in drying process S24 is made to contact silver nitrate aqueous solution (contact process S25). In this manner, by dropping a solution containing metal ions such as copper ions before bringing the adsorbent into contact with the aqueous silver nitrate solution, it is possible to adsorb gases such as ammonia and hydrogen sulfide due to the influence of metal ions supported on calcium phosphate. Can produce a complex. Moreover, since the silver phosphate particles are reduced by dropping the solution containing metal ions in this way, the photocatalytic activity is improved. In addition to copper ions, by dropping a solution containing other metal ions such as zinc ions, nickel, manganese, cobalt, etc., gas such as ammonia and hydrogen sulfide is affected by the influence of metal ions supported on calcium phosphate. A complex with improved adsorption capacity can be produced.
次に、本発明の一実施形態に係る可視光応答型光触媒複合体の実施例について、図面を使用しながら説明する。図５は、本発明の可視光応答型光触媒複合体の実施例１の一部を部分拡大した電子顕微鏡写真図であり、図６は、本発明の可視光応答型光触媒複合体の実施例２の一部を部分拡大した電子顕微鏡写真図である。また、図７は、本発明の可視光応答型光触媒複合体の比較例２の一部を部分拡大した電子顕微鏡写真図である。なお、本発明は、これらの実施例に限定されるものではない。 Next, examples of the visible light responsive photocatalyst complex according to one embodiment of the present invention will be described with reference to the drawings. FIG. 5 is an electron micrograph showing a part of Example 1 of the visible light responsive photocatalyst complex of the present invention, and FIG. 6 is Example 2 of the visible light responsive photocatalyst complex of the present invention. It is the electron microscope photograph figure which expanded a part of. FIG. 7 is an electron micrograph showing a partially enlarged view of part of Comparative Example 2 of the visible light responsive photocatalyst complex of the present invention. The present invention is not limited to these examples.
本実施例では、本発明の一実施形態に係る可視光応答型光触媒複合体を構成する吸着材の原材料や製造方法を変えた複数のサンプルとして、実施例１及び実施例２を用意した。また、これらの実施例の比較対象として、製造方法及び原材料等の条件を本実施形態に係る可視光応答型光触媒複合体と異なるもののサンプルとして、比較例１及び比較例２を用意した。そして、これらの実施例及び比較例のサンプルに対して、アンモニア分解試験を実施して、それぞれのサンプルに対する光触媒性能について検証した。 In this example, Example 1 and Example 2 were prepared as a plurality of samples in which the raw materials and manufacturing methods of the adsorbent constituting the visible light responsive photocatalyst complex according to one embodiment of the present invention were changed. Moreover, Comparative Example 1 and Comparative Example 2 were prepared as samples for comparison of these examples, with the production method and raw material conditions different from those of the visible light responsive photocatalyst complex according to the present embodiment. And the ammonia decomposition test was implemented with respect to the sample of these Examples and comparative examples, and the photocatalytic performance with respect to each sample was verified.
実施例１では、カルサイト構造の軽質炭酸カルシウムであるＰＣＣ−Ｂｒｉｌｌｉａｎｔ１５０（白石カルシウム製）２．０ｇを蒸留水５０ｍｌ入りのガラス製三角フラスコに加えて、ホットスターラーで６０℃になるまで撹拌した。そして、１Ｍリン酸水溶液１０ｍｌを滴定速度３．７５ｍｌ／ｍｉｎで滴下後、ろ過、水洗して、５０℃で乾燥させた。その後、かかる乾燥により得られた粉末１００ｍｇを容積５０ｍｌの遠沈管に加え、当該遠沈管に２０ｍＭの硝酸銀水溶液２．５ｍｌを滴下して、遠沈管に蓋をして軽く振った。そして、スラリーをろ過、水洗してから、５０℃で乾燥して薄黄色粉末を得た。 In Example 1, 2.0 g of PCC-Brilliant 150 (manufactured by calcium shiroishi), which is light calcium carbonate having a calcite structure, was added to a glass Erlenmeyer flask containing 50 ml of distilled water and stirred with a hot stirrer until the temperature reached 60 ° C. Then, 10 ml of 1M phosphoric acid aqueous solution was dropped at a titration rate of 3.75 ml / min, filtered, washed with water, and dried at 50 ° C. Thereafter, 100 mg of the powder obtained by the drying was added to a centrifuge tube having a volume of 50 ml, and 2.5 ml of a 20 mM silver nitrate aqueous solution was dropped into the centrifuge tube, and the centrifuge tube was covered and shaken lightly. The slurry was filtered and washed with water, and then dried at 50 ° C. to obtain a light yellow powder.
実施例１のサンプル粉末を電子顕微鏡で観察した。また、当該サンプル粉末の化学組成は、ＩＣＰ発光分光測定により行った。結晶構造は、Ｘ線回折により行った。Ｘ線回折結果により、リン酸８カルシウムとリン酸銀が確認された。また、ＩＣＰ分析によりＡｇが３．５ｗｔ％定量された。図５に実施例１のサンプル粉末の電子顕微鏡写真図を示す。図５に示すように、リン酸カルシウムの薄片の表面にリン酸銀のナノ粒子が高分散状態で当該薄片に担持されて複合化していることが分かった。すなわち、リン酸カルシウムからなる複数の薄片が空隙部を介して互いに凝集して生成される所謂フラワー形状の吸着材を構成する薄片の表面に、ナノ粒子状のリン酸銀が高分散状態で担持された複合体が生成していたことが分かった。 The sample powder of Example 1 was observed with an electron microscope. The chemical composition of the sample powder was measured by ICP emission spectrometry. The crystal structure was performed by X-ray diffraction. X-ray diffraction results confirmed 8 calcium phosphate and silver phosphate. In addition, 3.5 wt% of Ag was determined by ICP analysis. FIG. 5 shows an electron micrograph of the sample powder of Example 1. As shown in FIG. 5, it was found that the silver phosphate nanoparticles were supported on the flakes in a highly dispersed state on the surface of the calcium phosphate flakes and were complexed. That is, nanoparticulate silver phosphate was supported in a highly dispersed state on the surface of a thin piece constituting a so-called flower-shaped adsorbent produced by agglomerating a plurality of thin pieces made of calcium phosphate through a void. It was found that a complex was formed.
一方、実施例２では、アラゴナイト構造の炭酸カルシウムであるアコヤ貝殻粉末２．０ｇを蒸留水５０ｍｌ入りのガラス製三角フラスコに加えて、ホットスターラーで６０℃になるまで撹拌した。そして、１Ｍリン酸水溶液２０ｍｌを滴定速度３．７５ｍｌ／ｍｉｎで滴下後、ろ過、水洗してから、５０℃で乾燥させた。その後、かかる乾燥により得られた粉末２００ｍｇを容積１００ｍｌのガラス製ビーカーに加えて、そこに７ｍＭの硝酸銀水溶液５０ｍｌを加えて撹拌子で撹拌した。その後、スラリーをろ過、水洗してから、５０℃で乾燥して黄色粉末を得た。 On the other hand, in Example 2, 2.0 g of pearl oyster shell powder, which is calcium carbonate with an aragonite structure, was added to a glass Erlenmeyer flask containing 50 ml of distilled water and stirred with a hot stirrer until the temperature reached 60 ° C. Then, 20 ml of 1M phosphoric acid aqueous solution was dropped at a titration rate of 3.75 ml / min, filtered, washed with water, and dried at 50 ° C. Thereafter, 200 mg of the powder obtained by the drying was added to a glass beaker having a volume of 100 ml, and 50 ml of a 7 mM silver nitrate aqueous solution was added thereto and stirred with a stirring bar. Thereafter, the slurry was filtered, washed with water, and dried at 50 ° C. to obtain a yellow powder.
実施例２のサンプル粉末を電子顕微鏡で観察した。また、当該サンプル粉末の化学組成は、ＩＣＰ発光分光測定により行った。結晶構造は、Ｘ線回折により行った。Ｘ線回折結果により、実施例１と同様にリン酸８カルシウムとリン酸銀が確認された。また、ＩＣＰ分析によりＡｇが４ｗｔ％定量された。図６に実施例２のサンプル粉末の電子顕微鏡像を示す。図６に示すように、実施例２では、薄片そのものがリン酸銀になっている様子が確認されて、複合化して生成していた。すなわち、リン酸銀が薄片状に生成され、当該リン酸銀の薄片がリン酸カルシウムの薄片の表面又は端部の何れかに担持された複合体が生成していたことが分かった。換言すると、リン酸カルシウムの薄片の一部をリン酸銀の薄片に転換させて、リン酸カルシウムとリン酸銀を複合化されたものとなっていたことが分かった。 The sample powder of Example 2 was observed with an electron microscope. The chemical composition of the sample powder was measured by ICP emission spectrometry. The crystal structure was performed by X-ray diffraction. X-ray diffraction results confirmed 8 calcium phosphate and silver phosphate as in Example 1. Further, 4 wt% of Ag was quantified by ICP analysis. FIG. 6 shows an electron microscopic image of the sample powder of Example 2. As shown in FIG. 6, in Example 2, it was confirmed that the flakes themselves were silver phosphate, and the flakes were formed in a composite form. That is, it was found that silver phosphate was produced in the form of flakes, and a composite in which the silver phosphate flakes were carried on either the surface or the end of the calcium phosphate flakes was produced. In other words, it was found that a part of the calcium phosphate flakes was converted into a silver phosphate flake to form a composite of calcium phosphate and silver phosphate.
また、比較例１では、１００ｍｌのガラス製三角フラスコに０．１５ＭのAgNO3水溶液５０ｍｌを加え、撹拌しながら、そこへ０．０５ＭのNa2HPO4水溶液５０ｍｌを加えて、３０分間撹拌してから、スラリーをろ過、水洗して、７０℃で乾燥後に濃黄色粉末を得た。黄色粉末のＸ線回折結果からリン酸銀が生成していた。この粉末と実施例１で得られた所謂フラワー状粒子であるリン酸カルシウムからなる吸着材を実施例１のAg含有量と同じになるように物理混合した。物理混合後の粉末を蒸留水５０ｍｌ中に加えて、均一に混ざり合うように３０分間撹拌した。これらを５０℃で乾燥し、薄黄色粉末を得た。 In Comparative Example 1, 50 ml of a 0.15 M AgNO 3 aqueous solution was added to a 100 ml glass Erlenmeyer flask, and 50 ml of a 0.05 M Na 2 HPO 4 aqueous solution was added thereto while stirring for 30 minutes. The slurry was filtered, washed with water, and dried at 70 ° C. to obtain a dark yellow powder. From the X-ray diffraction result of the yellow powder, silver phosphate was produced. This powder and an adsorbent made of calcium phosphate, which is the so-called flower-like particles obtained in Example 1, were physically mixed so as to have the same Ag content as in Example 1. The powder after physical mixing was added to 50 ml of distilled water and stirred for 30 minutes so as to mix uniformly. These were dried at 50 ° C. to obtain a light yellow powder.
一方、比較例２では、特願２０１１−７５３１２の明細書に記載の吸着剤試料を調製した。ハイドロキシアパタイトは、ＷＡＫＯ（登録商標）製のものを用いた。蒸留水２００ｍｌに硝酸銀を１．７５ｇ溶解させて硝酸銀水溶液を調製した。この水溶液にハイドロキシアパタイト１０ｇを添加し、室温・遮光下で３時間撹拌した。その後、これをろ過し、固形分を水洗し、１００℃で乾燥させ、茶色粉末を得た。当該茶色粉末には、Ａｇが１０ｗｔ％含まれていた。図７に比較例２のサンプル粉末の電子顕微鏡像を示す。図７に示すように、ハイドロキシアパタイトが略六角柱形状の結晶構造のため、リン酸銀が凝集されて塊状となって、ハイドロキシアパタイトと複合化できていないことが分かった。 On the other hand, in Comparative Example 2, an adsorbent sample described in the specification of Japanese Patent Application No. 2011-75312 was prepared. As the hydroxyapatite, a product manufactured by WAKO (registered trademark) was used. A silver nitrate aqueous solution was prepared by dissolving 1.75 g of silver nitrate in 200 ml of distilled water. 10 g of hydroxyapatite was added to this aqueous solution and stirred for 3 hours at room temperature and under light shielding. Then, this was filtered, solid content was washed with water, and it was made to dry at 100 degreeC, and the brown powder was obtained. The brown powder contained 10 wt% Ag. FIG. 7 shows an electron microscope image of the sample powder of Comparative Example 2. As shown in FIG. 7, since hydroxyapatite has a substantially hexagonal columnar crystal structure, it was found that silver phosphate was aggregated into a lump and could not be combined with hydroxyapatite.
次に、前述した実施例１、実施例２、比較例１、及び比較例２のサンプル粉末に対して、当該サンプル粉末の可視光に対する光触媒性能を確認するために、アンモニア分解試験を実施した。 Next, an ammonia decomposition test was performed on the sample powders of Example 1, Example 2, Comparative Example 1, and Comparative Example 2 described above in order to confirm the photocatalytic performance of the sample powder with respect to visible light.
アンモニア分解試験は、２８％アンモニア水をＤＷで１０倍希釈し、１Ｌガスバックにφ９５ｍｍのシャーレに分散させた各試料を１００ｍｇずつ入れて、ガスバッグを密閉した。その後、空気を導入後に希釈アンモニア水をシリンジで５μＬを導入して、２０℃に設定された恒温槽に入れた。そして、決められた時間にアンモニア検知管で濃度を測定した。その後、アンモニア濃度が一定になった時点で青色ＬＥＤを照射して、照射後のアンモニア濃度を測定した。 In the ammonia decomposition test, 28% ammonia water was diluted 10-fold with DW, and 100 mg of each sample dispersed in a petri dish of φ95 mm was placed in a 1 L gas bag, and the gas bag was sealed. Then, after introducing air, 5 μL of diluted ammonia water was introduced with a syringe and placed in a thermostat set at 20 ° C. Then, the concentration was measured with an ammonia detector tube at a predetermined time. Thereafter, when the ammonia concentration became constant, the blue LED was irradiated, and the ammonia concentration after irradiation was measured.
実施例１、実施例２、比較例１、及び比較例２の試験結果を図８に示す。図８は、本発明の可視光応答型光触媒複合体の実施例及び比較例によるアンモニア分解試験の結果を示すグラフである。図８に示すように、これらの試験結果から、ＬＥＤ照射を開始してからアンモニアの濃度減少を示したのは、実施例１及び実施例２のみであった。このことから、実施例１及び実施例２のサンプル粉末は、可視光に対する光触媒活性を有することが分かった。 The test results of Example 1, Example 2, Comparative Example 1, and Comparative Example 2 are shown in FIG. FIG. 8 is a graph showing the results of ammonia decomposition tests according to examples and comparative examples of the visible light responsive photocatalyst complex of the present invention. As shown in FIG. 8, from these test results, only Example 1 and Example 2 showed a decrease in ammonia concentration after the start of LED irradiation. From this, it turned out that the sample powder of Example 1 and Example 2 has photocatalytic activity with respect to visible light.
すなわち、実施例１では、吸着材を構成するリン酸カルシウムの薄片の表面にリン酸銀の粒子が高分散状態で担持されるので、可視光応答型光触媒としての高い光触媒性能を維持した上で、吸着材としての吸着性能を確保できる。また、実施例２では、吸着材を構成するリン酸カルシウムの薄片間に有する空隙部を架橋するように、リン酸銀の薄片が高分散状態で担持されるので、可視光応答型光触媒としての高い光触媒性能を維持した上で、吸着材としての吸着性能を確保できる。 That is, in Example 1, since the silver phosphate particles are supported in a highly dispersed state on the surface of the calcium phosphate flakes constituting the adsorbent, the adsorption is performed while maintaining high photocatalytic performance as a visible light responsive photocatalyst. Adsorption performance as a material can be secured. Further, in Example 2, since the silver phosphate flakes are supported in a highly dispersed state so as to bridge the voids between the calcium phosphate flakes constituting the adsorbent, a high photocatalyst as a visible light responsive photocatalyst Adsorption performance as an adsorbent can be ensured while maintaining performance.
一方、比較例１のように、単にリン酸銀とリン酸カルシウムを物理混合するだけでは、これらリン酸銀とリン酸カルシウムの複合化ができず、かつ、リン酸銀の分散性が悪いため、光触媒活性を示さないことが明らかになった。すなわち、所謂フラワー形状のリン酸カルシウムとリン酸銀との物理混合体では、光触媒活性を示さないことが分かった。 On the other hand, as in Comparative Example 1, simply by physically mixing silver phosphate and calcium phosphate, these silver phosphate and calcium phosphate cannot be combined, and the dispersibility of silver phosphate is poor, so photocatalytic activity is improved. It became clear not to show. That is, it was found that a physical mixture of so-called flower-shaped calcium phosphate and silver phosphate does not exhibit photocatalytic activity.
また、比較例２のように、リン酸カルシウムの形状が単一の略六角柱の塊状で、かつ、ハイドロキシアパタイト構造のものは、リン酸銀と複合化できず、銀含有量が１０ｗｔ％であるにも関わらず、光触媒活性を示さなかった。すなわち、複数の薄片を空隙部を介して凝集させた所謂フラワー形状でないリン酸カルシウムの吸着材では、リン酸銀が当該吸着材と複合化されずに、光触媒活性を示さないことが分かった。これは、吸着材が略六角柱形状等の厚い構造だと、リン酸銀粒子が凝集して、可視光に対する光触媒活性の低い塊状のリン酸銀に変化したためと考えられる。 Further, as in Comparative Example 2, a calcium phosphate having a single hexagonal column shape and having a hydroxyapatite structure cannot be combined with silver phosphate, and the silver content is 10 wt%. Nevertheless, it did not show photocatalytic activity. That is, it was found that a so-called flower-shaped calcium phosphate adsorbent obtained by aggregating a plurality of flakes through a gap does not show photocatalytic activity because silver phosphate is not complexed with the adsorbent. This is considered to be because when the adsorbent has a thick structure such as a substantially hexagonal column shape, the silver phosphate particles aggregated and changed to a massive silver phosphate having low photocatalytic activity for visible light.
このように、リン酸カルシウムでも、リン酸銀が高分散状態で複合化させる吸着材は、リン酸カルシウムの薄片が寄り集まったフラワー形状を有する吸着材のみで、その他の形状の吸着材では、リン酸銀が吸着材と複合化されない。すなわち、リン酸銀と複合化されていない吸着材の形状では、可視光照射下で光触媒活性を示さないことが分かった。 As described above, even with calcium phosphate, the only adsorbent that can be combined with silver phosphate in a highly dispersed state is an adsorbent having a flower shape in which flakes of calcium phosphate are gathered together. Not combined with adsorbent. That is, it was found that the shape of the adsorbent not complexed with silver phosphate does not show photocatalytic activity under visible light irradiation.
次に、本発明の一実施形態に係る可視光応答型光触媒複合体の製造方法により生成された可視光応答型光触媒複合体の実施例と、本発明の他の実施形態に係る可視光応答型光触媒複合体の製造方法により生成された可視光応答型光触媒複合体の実施例における吸着試験結果について、図面を使用しながら説明する。図９は、アンモニア吸着試験の結果を示すグラフであり、図１０は、硫化水素吸着試験の結果を示すグラフであり、図１１は、酢酸吸着試験の結果を示すグラフである。 Next, an example of a visible light responsive photocatalyst complex produced by a method for producing a visible light responsive photocatalyst complex according to an embodiment of the present invention, and a visible light responsive type according to another embodiment of the present invention The adsorption test results in the examples of the visible light responsive photocatalyst complex produced by the method for producing the photocatalyst complex will be described with reference to the drawings. FIG. 9 is a graph showing the results of the ammonia adsorption test, FIG. 10 is a graph showing the results of the hydrogen sulfide adsorption test, and FIG. 11 is a graph showing the results of the acetic acid adsorption test.
まず、吸着試験対象となる試料として、前述したリン酸銀とリン酸カルシウムの複合体となる実施例１（AgCaP）と、当該実施例１の複合体を生成する過程で硝酸銀水溶液と接触させる前に、硝酸銅水溶液に接触させたものを５０℃で乾燥してから、硝酸銀水溶液を接触させて生成した実施例３に係る複合体（CuAgCaP）を用意する。また、同様にして、当該実施例１の複合体を生成する過程で硝酸銀水溶液と接触させる前に、硝酸亜鉛水溶液に接触させたものを５０℃で乾燥してから、硝酸銀水溶液を接触させた実施例４に係る複合体（ZnAgCaP）を用意する。 First, as a sample to be subjected to an adsorption test, Example 1 (AgCaP), which is a composite of silver phosphate and calcium phosphate described above, and before contacting with a silver nitrate aqueous solution in the process of generating the composite of Example 1, A composite (CuAgCaP) according to Example 3 prepared by contacting a silver nitrate aqueous solution with a silver nitrate aqueous solution after being dried at 50 ° C. is prepared. Similarly, before the contact with the silver nitrate aqueous solution in the process of forming the composite of Example 1, the contact with the zinc nitrate aqueous solution was dried at 50 ° C. and then contacted with the silver nitrate aqueous solution. A composite according to Example 4 (ZnAgCaP) is prepared.
次に、これらの実施例１、実施例３、及び実施例４に係る複合体に対して、それぞれ下記の条件で吸着試験を実施した。なお、アンモニア吸着試験は、実施例１、実施例３、及び実施例４に係る複合体に対してそれぞれ実施し、硫化水素吸着試験及び酢酸吸着試験は、実施例１及び実施例３に係る複合体に対してそれぞれ実施した。 Next, adsorption tests were performed on the composites according to Example 1, Example 3, and Example 4 under the following conditions, respectively. The ammonia adsorption test was performed on the composites according to Example 1, Example 3, and Example 4, and the hydrogen sulfide adsorption test and the acetic acid adsorption test were performed on the composites according to Example 1 and Example 3. Each was performed on the body.
アンモニア吸着試験は、２８％アンモニア水を蒸留水で１０倍希釈し、１Ｌガスバックにφ９５ｍｍのシャーレに分散させた各試料を１００ｍｇずつ入れて、当該ガスバッグを密閉した。その後、空気を導入後に希釈アンモニア水をシリンジで7μＬを導入して、２０℃に設定された恒温槽に入れた。そして、決められた時間にアンモニア検知管で濃度を測定した。 In the ammonia adsorption test, 28% ammonia water was diluted 10-fold with distilled water, 100 mg of each sample dispersed in a petri dish with a diameter of 95 mm was placed in a 1 L gas bag, and the gas bag was sealed. Then, after introducing air, 7 μL of diluted ammonia water was introduced with a syringe and placed in a thermostat set at 20 ° C. Then, the concentration was measured with an ammonia detector tube at a predetermined time.
硫化水素吸着試験は、１Ｌガスバックにφ９５ｍｍのシャーレに分散させた各試料を１００ｍｇずつ入れて、当該ガスバッグを密閉した。その後、空気を導入後に硫化水素標準ガスをシリンジで導入して、２０℃に設定された恒温槽に入れた。そして、決められた時間に硫化水素検知管で濃度を測定した。 In the hydrogen sulfide adsorption test, 100 mg of each sample dispersed in a petri dish with a diameter of 95 mm was placed in a 1 L gas bag, and the gas bag was sealed. Then, after introducing air, hydrogen sulfide standard gas was introduced with a syringe and placed in a thermostat set to 20 ° C. Then, the concentration was measured with a hydrogen sulfide detector tube at a predetermined time.
酢酸吸着試験は、酢酸を蒸留水で５０倍希釈し、１Ｌガスバックにφ９５ｍｍのシャーレに分散させた各試料を１００ｍｇずつ入れて、ガスバッグを密閉した。その後、空気を導入後に希釈酢酸をシリンジで５μＬを導入して、２０℃に設定された恒温槽に入れた。そして、決められた時間に酢酸検知管で濃度を測定した。 In the acetic acid adsorption test, acetic acid was diluted 50 times with distilled water, 100 mg of each sample dispersed in a petri dish of φ95 mm was placed in a 1 L gas bag, and the gas bag was sealed. Then, after introducing air, 5 μL of diluted acetic acid was introduced with a syringe and placed in a thermostat set at 20 ° C. Then, the concentration was measured with an acetic acid detector tube at a predetermined time.
アンモニア吸着試験の結果を見ると、図９に示すように、銅イオンを担持させた実施例３の複合体、及び亜鉛イオンを担持させた実施例４の複合体の方が実施例１の複合体よりもアンモニアの吸着量が多いことが分かる。これは、複合体に含まれる吸着材に銅や亜鉛等の金属イオンを担持することによって、金属イオンとアンモニアがアンミン錯体化合物を形成するため、アンモニアガスの吸着力が高められたものと考えられる。 Looking at the results of the ammonia adsorption test, as shown in FIG. 9, the composite of Example 3 supporting copper ions and the composite of Example 4 supporting zinc ions are more complex than Example 1. It can be seen that the amount of adsorption of ammonia is higher than that of the body. This is thought to be due to the fact that the metal ions and ammonia form an ammine complex compound by supporting metal ions such as copper and zinc on the adsorbent contained in the composite, so that the adsorption power of ammonia gas is enhanced. .
また、硫化水素吸着試験の結果を見ると、図１０に示すように、実施例１の複合体では、あまり硫化水素の吸着量が多くないが、銅イオンを担持させた実施例３の複合体では、硫化水素の吸着量が大幅に増加したことが分かる。これは、複合体に含まれる吸着材に銅等の金属イオンを担持することによって、金属イオン（Ｍ）と硫化水素がＭ−Ｓ結合を形成するため、硫化水素ガスの吸着力を高められたものと考えられる。 Further, the results of the hydrogen sulfide adsorption test show that, as shown in FIG. 10, the composite of Example 1 does not have much hydrogen sulfide adsorption, but the composite of Example 3 supporting copper ions. Then, it turns out that the adsorption amount of hydrogen sulfide increased significantly. This is because the metal ions (M) and hydrogen sulfide form an MS bond by supporting metal ions such as copper on the adsorbent contained in the composite, so that the adsorption power of hydrogen sulfide gas can be enhanced. It is considered a thing.
さらに、酢酸吸着試験の結果を見ると、図１１に示すように、銅イオンを担持させた実施例３の複合体の方が実施例１の複合体よりも、より早く酢酸の吸着が完了することが分かる。これは、複合体に含まれる吸着材に銅等の金属イオンを担持することによって、金属イオン（Ｍ）と酢酸がＭ−ＣＯＯＨ結合を形成するため、酢酸ガスの吸着速度を大きくして吸着力を高められたものと考えられる。 Further, when the results of the acetic acid adsorption test are seen, as shown in FIG. 11, the adsorption of acetic acid is completed earlier in the complex of Example 3 supporting copper ions than in the complex of Example 1. I understand that. This is because the metal ions (M) and acetic acid form M-COOH bonds by supporting metal ions such as copper on the adsorbent contained in the composite, so that the adsorption rate of acetic acid gas is increased and the adsorption power is increased. Is considered to have been raised.
なお、上記のように本発明の各実施形態及び各実施例について詳細に説明したが、本発明の新規事項及び効果から実体的に逸脱しない多くの変形が可能であることは、当業者には、容易に理解できるであろう。従って、このような変形例は、全て本発明の範囲に含まれるものとする。 Although the embodiments and examples of the present invention have been described in detail as described above, it will be understood by those skilled in the art that many modifications can be made without departing from the novel matters and effects of the present invention. It will be easy to understand. Therefore, all such modifications are included in the scope of the present invention.
例えば、明細書又は図面において、少なくとも一度、より広義又は同義な異なる用語と共に記載された用語は、明細書又は図面のいかなる箇所においても、その異なる用語に置き換えることができる。また、可視光応答型光触媒複合体の構成、動作も本発明の各実施形態及び各実施例で説明したものに限定されず、種々の変形実施が可能である。 For example, a term described with a different term having a broader meaning or the same meaning at least once in the specification or the drawings can be replaced with the different term in any part of the specification or the drawings. Further, the configuration and operation of the visible light responsive photocatalyst complex are not limited to those described in the embodiments and examples of the present invention, and various modifications can be made.
１０、２０ リン酸カルシウム、１２ 水和層、１４、２４、２４ａ リン酸銀、Ｓ１１、Ｓ２１ 分散工程（リン酸カルシウム生成工程）、Ｓ１２、Ｓ２２ 滴下工程（リン酸カルシウム生成工程）、Ｓ１３、Ｓ２４ 吸着材生成工程、Ｓ１４、Ｓ２５ 接触工程、Ｓ２３ 金属イオン滴下工程 10, 20 Calcium phosphate, 12 Hydrated layer, 14, 24, 24a Silver phosphate, S11, S21 Dispersing step (calcium phosphate producing step), S12, S22 Dropping step (calcium phosphate producing step), S13, S24 Adsorbent producing step, S14 , S25 contact step, S23 metal ion dropping step
Claims (9)
リン酸カルシウムからなる複数の薄片が空隙部を介して互いに凝集して生成される吸着材と、
前記薄片の表面又は端部の何れかに分散状態に担持されるリン酸銀からなる可視光応答型光触媒と、を含むことを特徴とする可視光応答型光触媒複合体。 A visible light responsive photocatalyst complex that exhibits photocatalytic activity in the visible light wavelength region,
An adsorbent produced by agglomerating a plurality of flakes made of calcium phosphate together through a void;
A visible light responsive photocatalyst composite comprising a visible light responsive photocatalyst made of silver phosphate supported in a dispersed state on either the surface or the end of the flake.
カルシウム化合物を分散させた溶媒に所定量のリン酸水溶液を滴下して複数のリン酸カルシウムの薄片を生成するリン酸カルシウム生成工程と、
前記複数のリン酸カルシウムの薄片をろ過してから乾燥させて複数の薄片状の前記リン酸カルシウムが空隙部を介して凝集して構成される前記吸着材を生成する吸着材生成工程と、
乾燥後の前記吸着材を硝酸銀水溶液に接触させて前記リン酸カルシウムの前記薄片にリン酸銀を担持させる接触工程と、を含むことを特徴とする可視光応答型光触媒複合体の製造方法。 A method for producing a visible light responsive photocatalyst complex in which a visible light responsive photocatalyst is combined with an adsorbent,
A calcium phosphate production step of dropping a predetermined amount of a phosphoric acid aqueous solution into a solvent in which a calcium compound is dispersed to produce a plurality of calcium phosphate flakes ;
An adsorbent generating step for generating the adsorbent formed by filtering and drying the plurality of calcium phosphate flakes and aggregating the plurality of flake-like calcium phosphates through voids ;
Method of manufacturing a visible-light-responsive photocatalytic composite, characterized in that the adsorbent after drying is brought into contact with the aqueous silver nitrate solution containing a contact step of Ru by supporting silver phosphate in the flakes of the calcium phosphate.
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