JP2008006328A - Photocatalyst comprising visible light responsive composite oxide semiconductor - Google Patents
Photocatalyst comprising visible light responsive composite oxide semiconductor Download PDFInfo
- Publication number
- JP2008006328A JP2008006328A JP2006176577A JP2006176577A JP2008006328A JP 2008006328 A JP2008006328 A JP 2008006328A JP 2006176577 A JP2006176577 A JP 2006176577A JP 2006176577 A JP2006176577 A JP 2006176577A JP 2008006328 A JP2008006328 A JP 2008006328A
- Authority
- JP
- Japan
- Prior art keywords
- visible light
- photocatalyst
- light responsive
- oxide
- light
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
- 239000011941 photocatalyst Substances 0.000 title claims abstract description 44
- 239000004065 semiconductor Substances 0.000 title claims abstract description 16
- 239000002131 composite material Substances 0.000 title claims abstract description 10
- 229910052751 metal Inorganic materials 0.000 claims abstract description 19
- 239000002184 metal Substances 0.000 claims abstract description 15
- 239000006104 solid solution Substances 0.000 claims abstract description 15
- 229910052708 sodium Inorganic materials 0.000 claims abstract description 9
- 229910052792 caesium Inorganic materials 0.000 claims abstract description 7
- 229910052744 lithium Inorganic materials 0.000 claims abstract description 7
- 229910052700 potassium Inorganic materials 0.000 claims abstract description 7
- 229910052701 rubidium Inorganic materials 0.000 claims abstract description 7
- 239000000203 mixture Substances 0.000 claims description 4
- 239000000463 material Substances 0.000 abstract description 34
- 230000001699 photocatalysis Effects 0.000 abstract description 24
- GWEVSGVZZGPLCZ-UHFFFAOYSA-N Titan oxide Chemical compound O=[Ti]=O GWEVSGVZZGPLCZ-UHFFFAOYSA-N 0.000 abstract description 14
- OGIDPMRJRNCKJF-UHFFFAOYSA-N titanium oxide Inorganic materials [Ti]=O OGIDPMRJRNCKJF-UHFFFAOYSA-N 0.000 abstract description 13
- 229910052709 silver Inorganic materials 0.000 abstract description 9
- 239000004332 silver Substances 0.000 abstract description 9
- 239000003054 catalyst Substances 0.000 abstract description 7
- 230000003197 catalytic effect Effects 0.000 abstract description 7
- 229910052758 niobium Inorganic materials 0.000 abstract description 7
- 239000010955 niobium Substances 0.000 abstract description 7
- GUCVJGMIXFAOAE-UHFFFAOYSA-N niobium atom Chemical compound [Nb] GUCVJGMIXFAOAE-UHFFFAOYSA-N 0.000 abstract description 7
- 229910052802 copper Inorganic materials 0.000 abstract description 4
- 239000000243 solution Substances 0.000 abstract description 4
- 229910052783 alkali metal Inorganic materials 0.000 abstract description 3
- 150000001340 alkali metals Chemical class 0.000 abstract description 3
- 230000005855 radiation Effects 0.000 abstract 1
- 238000000034 method Methods 0.000 description 18
- 239000000126 substance Substances 0.000 description 16
- 239000011734 sodium Substances 0.000 description 15
- CSCPPACGZOOCGX-UHFFFAOYSA-N Acetone Chemical compound CC(C)=O CSCPPACGZOOCGX-UHFFFAOYSA-N 0.000 description 14
- CURLTUGMZLYLDI-UHFFFAOYSA-N Carbon dioxide Chemical compound O=C=O CURLTUGMZLYLDI-UHFFFAOYSA-N 0.000 description 12
- 230000000694 effects Effects 0.000 description 12
- KFZMGEQAYNKOFK-UHFFFAOYSA-N Isopropanol Chemical compound CC(C)O KFZMGEQAYNKOFK-UHFFFAOYSA-N 0.000 description 11
- 238000006243 chemical reaction Methods 0.000 description 8
- NDVLTYZPCACLMA-UHFFFAOYSA-N silver oxide Chemical compound [O-2].[Ag+].[Ag+] NDVLTYZPCACLMA-UHFFFAOYSA-N 0.000 description 8
- 239000002994 raw material Substances 0.000 description 7
- 239000001569 carbon dioxide Substances 0.000 description 6
- 229910002092 carbon dioxide Inorganic materials 0.000 description 6
- 238000000354 decomposition reaction Methods 0.000 description 6
- 239000012071 phase Substances 0.000 description 6
- 239000000843 powder Substances 0.000 description 5
- 238000003746 solid phase reaction Methods 0.000 description 5
- IJGRMHOSHXDMSA-UHFFFAOYSA-N Atomic nitrogen Chemical compound N#N IJGRMHOSHXDMSA-UHFFFAOYSA-N 0.000 description 4
- 241000894006 Bacteria Species 0.000 description 4
- CDBYLPFSWZWCQE-UHFFFAOYSA-L Sodium Carbonate Chemical compound [Na+].[Na+].[O-]C([O-])=O CDBYLPFSWZWCQE-UHFFFAOYSA-L 0.000 description 4
- 229910010413 TiO 2 Inorganic materials 0.000 description 4
- 230000000844 anti-bacterial effect Effects 0.000 description 4
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 description 4
- 238000004140 cleaning Methods 0.000 description 4
- 230000007613 environmental effect Effects 0.000 description 4
- 230000001747 exhibiting effect Effects 0.000 description 4
- 238000010304 firing Methods 0.000 description 4
- 239000007789 gas Substances 0.000 description 4
- 238000005259 measurement Methods 0.000 description 4
- 229910021645 metal ion Inorganic materials 0.000 description 4
- 229910052760 oxygen Inorganic materials 0.000 description 4
- 239000001301 oxygen Substances 0.000 description 4
- 238000005215 recombination Methods 0.000 description 4
- 230000006798 recombination Effects 0.000 description 4
- 229910001923 silver oxide Inorganic materials 0.000 description 4
- 238000000862 absorption spectrum Methods 0.000 description 3
- 230000015572 biosynthetic process Effects 0.000 description 3
- 230000008859 change Effects 0.000 description 3
- 229910052804 chromium Inorganic materials 0.000 description 3
- 230000000052 comparative effect Effects 0.000 description 3
- 239000005556 hormone Substances 0.000 description 3
- 229940088597 hormone Drugs 0.000 description 3
- 238000004519 manufacturing process Methods 0.000 description 3
- 150000002739 metals Chemical class 0.000 description 3
- 229910052757 nitrogen Inorganic materials 0.000 description 3
- 239000005416 organic matter Substances 0.000 description 3
- 230000001590 oxidative effect Effects 0.000 description 3
- IGFHQQFPSIBGKE-UHFFFAOYSA-N 4-nonylphenol Chemical compound CCCCCCCCCC1=CC=C(O)C=C1 IGFHQQFPSIBGKE-UHFFFAOYSA-N 0.000 description 2
- DGAQECJNVWCQMB-PUAWFVPOSA-M Ilexoside XXIX Chemical compound C[C@@H]1CC[C@@]2(CC[C@@]3(C(=CC[C@H]4[C@]3(CC[C@@H]5[C@@]4(CC[C@@H](C5(C)C)OS(=O)(=O)[O-])C)C)[C@@H]2[C@]1(C)O)C)C(=O)O[C@H]6[C@@H]([C@H]([C@@H]([C@H](O6)CO)O)O)O.[Na+] DGAQECJNVWCQMB-PUAWFVPOSA-M 0.000 description 2
- BQCADISMDOOEFD-UHFFFAOYSA-N Silver Chemical compound [Ag] BQCADISMDOOEFD-UHFFFAOYSA-N 0.000 description 2
- 241000700605 Viruses Species 0.000 description 2
- 238000010521 absorption reaction Methods 0.000 description 2
- 150000001299 aldehydes Chemical class 0.000 description 2
- PNEYBMLMFCGWSK-UHFFFAOYSA-N aluminium oxide Inorganic materials [O-2].[O-2].[O-2].[Al+3].[Al+3] PNEYBMLMFCGWSK-UHFFFAOYSA-N 0.000 description 2
- 238000000975 co-precipitation Methods 0.000 description 2
- 230000007547 defect Effects 0.000 description 2
- 238000013461 design Methods 0.000 description 2
- 238000011161 development Methods 0.000 description 2
- 238000005516 engineering process Methods 0.000 description 2
- 239000012535 impurity Substances 0.000 description 2
- 230000001678 irradiating effect Effects 0.000 description 2
- 238000002156 mixing Methods 0.000 description 2
- 239000004570 mortar (masonry) Substances 0.000 description 2
- 229910000484 niobium oxide Inorganic materials 0.000 description 2
- URLJKFSTXLNXLG-UHFFFAOYSA-N niobium(5+);oxygen(2-) Chemical compound [O-2].[O-2].[O-2].[O-2].[O-2].[Nb+5].[Nb+5] URLJKFSTXLNXLG-UHFFFAOYSA-N 0.000 description 2
- 239000002245 particle Substances 0.000 description 2
- 238000013032 photocatalytic reaction Methods 0.000 description 2
- 238000010298 pulverizing process Methods 0.000 description 2
- 238000011160 research Methods 0.000 description 2
- SQGYOTSLMSWVJD-UHFFFAOYSA-N silver(1+) nitrate Chemical compound [Ag+].[O-]N(=O)=O SQGYOTSLMSWVJD-UHFFFAOYSA-N 0.000 description 2
- 229910000029 sodium carbonate Inorganic materials 0.000 description 2
- 238000003980 solgel method Methods 0.000 description 2
- 238000001228 spectrum Methods 0.000 description 2
- 238000012360 testing method Methods 0.000 description 2
- 229910052720 vanadium Inorganic materials 0.000 description 2
- UGFAIRIUMAVXCW-UHFFFAOYSA-N Carbon monoxide Chemical compound [O+]#[C-] UGFAIRIUMAVXCW-UHFFFAOYSA-N 0.000 description 1
- BVKZGUZCCUSVTD-UHFFFAOYSA-L Carbonate Chemical compound [O-]C([O-])=O BVKZGUZCCUSVTD-UHFFFAOYSA-L 0.000 description 1
- 241000195493 Cryptophyta Species 0.000 description 1
- 241000233866 Fungi Species 0.000 description 1
- QAOWNCQODCNURD-UHFFFAOYSA-L Sulfate Chemical compound [O-]S([O-])(=O)=O QAOWNCQODCNURD-UHFFFAOYSA-L 0.000 description 1
- 244000269722 Thea sinensis Species 0.000 description 1
- 238000002441 X-ray diffraction Methods 0.000 description 1
- 239000002253 acid Substances 0.000 description 1
- 230000009471 action Effects 0.000 description 1
- 239000003905 agrochemical Substances 0.000 description 1
- 150000001298 alcohols Chemical class 0.000 description 1
- 150000004703 alkoxides Chemical class 0.000 description 1
- 150000001412 amines Chemical class 0.000 description 1
- 150000001450 anions Chemical class 0.000 description 1
- 230000000840 anti-viral effect Effects 0.000 description 1
- 239000007864 aqueous solution Substances 0.000 description 1
- 150000001491 aromatic compounds Chemical class 0.000 description 1
- 239000003212 astringent agent Substances 0.000 description 1
- 238000001354 calcination Methods 0.000 description 1
- 229910002091 carbon monoxide Inorganic materials 0.000 description 1
- 150000001732 carboxylic acid derivatives Chemical class 0.000 description 1
- 238000005229 chemical vapour deposition Methods 0.000 description 1
- 150000001875 compounds Chemical class 0.000 description 1
- 239000004567 concrete Substances 0.000 description 1
- 238000011109 contamination Methods 0.000 description 1
- 238000004332 deodorization Methods 0.000 description 1
- 238000000151 deposition Methods 0.000 description 1
- 238000001514 detection method Methods 0.000 description 1
- 238000010586 diagram Methods 0.000 description 1
- 238000001035 drying Methods 0.000 description 1
- 239000003344 environmental pollutant Substances 0.000 description 1
- 238000005530 etching Methods 0.000 description 1
- 230000005284 excitation Effects 0.000 description 1
- 238000004817 gas chromatography Methods 0.000 description 1
- 239000000383 hazardous chemical Substances 0.000 description 1
- 229930195733 hydrocarbon Natural products 0.000 description 1
- 150000002430 hydrocarbons Chemical class 0.000 description 1
- 238000001027 hydrothermal synthesis Methods 0.000 description 1
- 239000002917 insecticide Substances 0.000 description 1
- 230000003993 interaction Effects 0.000 description 1
- 150000002576 ketones Chemical class 0.000 description 1
- 229910001510 metal chloride Inorganic materials 0.000 description 1
- 229910001960 metal nitrate Inorganic materials 0.000 description 1
- 229910017464 nitrogen compound Inorganic materials 0.000 description 1
- 150000002830 nitrogen compounds Chemical class 0.000 description 1
- 150000002896 organic halogen compounds Chemical class 0.000 description 1
- 150000002903 organophosphorus compounds Chemical class 0.000 description 1
- 230000003647 oxidation Effects 0.000 description 1
- 238000007254 oxidation reaction Methods 0.000 description 1
- 238000006116 polymerization reaction Methods 0.000 description 1
- 238000002360 preparation method Methods 0.000 description 1
- 102000004169 proteins and genes Human genes 0.000 description 1
- 108090000623 proteins and genes Proteins 0.000 description 1
- 238000011002 quantification Methods 0.000 description 1
- 238000006722 reduction reaction Methods 0.000 description 1
- 150000003839 salts Chemical class 0.000 description 1
- 238000007493 shaping process Methods 0.000 description 1
- 208000008842 sick building syndrome Diseases 0.000 description 1
- 229910001961 silver nitrate Inorganic materials 0.000 description 1
- 238000005245 sintering Methods 0.000 description 1
- 239000000344 soap Substances 0.000 description 1
- 238000010532 solid phase synthesis reaction Methods 0.000 description 1
- 238000004544 sputter deposition Methods 0.000 description 1
- 238000000859 sublimation Methods 0.000 description 1
- 230000008022 sublimation Effects 0.000 description 1
- 150000003464 sulfur compounds Chemical class 0.000 description 1
- 230000002194 synthesizing effect Effects 0.000 description 1
Images
Landscapes
- Inorganic Compounds Of Heavy Metals (AREA)
- Catalysts (AREA)
Abstract
Description
本発明は可視光応答性複合酸化物半導体からなる光触媒に関する。詳しくは、太陽光、室内照明などに含まれる紫外線は勿論、紫外線以外の可視光線に対しても高い光触媒活性を示す複合酸化物半導体からなる光触媒に関する。さらに詳しくは、バクテリアや菌類も含めた有害物質の分解あるいは、台所の汚れ等を分解清浄化しえる光触媒に関する。 The present invention relates to a photocatalyst comprising a visible light responsive complex oxide semiconductor. Specifically, the present invention relates to a photocatalyst made of a complex oxide semiconductor exhibiting a high photocatalytic activity with respect to visible light other than ultraviolet rays as well as ultraviolet rays contained in sunlight and indoor lighting. More specifically, the present invention relates to a photocatalyst that can decompose harmful substances including bacteria and fungi or decompose and clean kitchen dirt.
半導体光触媒は、そのバンドギャップ以上のエネルギーを有する光が照射されると価電子帯の電子が伝導帯に励起され、伝導帯、価電子帯にそれぞれ電子、ホールを生成する。特にホールは強い酸化力を持ち、さまざまな有機物質を酸化分解することができ、現在、脱臭や抗菌材料などさまざまな分野に応用されている。 When a semiconductor photocatalyst is irradiated with light having energy greater than its band gap, electrons in the valence band are excited to the conduction band, and electrons and holes are generated in the conduction band and the valence band, respectively. Halls in particular have a strong oxidizing power and can oxidize and decompose various organic substances, and are currently applied to various fields such as deodorization and antibacterial materials.
しかしながら、実用用途でもっともよく利用されているアナターゼ型酸化チタンのバンドギャップは３．２ｅＶと比較的大きく、３９０ｎｍより短い波長の紫外光に対しては極めて高い光触媒活性を示すことが知られているが、これより波長の長い波長領域、すなわち可視光領域の光に対して活性を示さない。 However, the band gap of anatase-type titanium oxide, which is most frequently used in practical applications, is relatively large at 3.2 eV, and is known to exhibit extremely high photocatalytic activity for ultraviolet light having a wavelength shorter than 390 nm. However, it does not show activity with respect to light having a wavelength longer than that, that is, visible light.
一方、光触媒材料の励起光源となる太陽光や蛍光灯に含まれている紫外線の量は、非常に少なく、可視光量の約４〜１０％しかない。換言すれば、自然光の大部分は可視光で占められており、従来の酸化チタンを光触媒材料として利用する場合、自然光の大部分を占める可視光領域を利用することができない。そのため、光の利用効率は極端に低く、とりわけ光の絶対量が少ない室内においては光触媒の機能が充分に発揮されず、室内での光触媒技術は、ほとんど使用されることもなく未利用状態のままに放置されていたといっても過言ではない。 On the other hand, the amount of ultraviolet rays contained in sunlight and fluorescent lamps that serve as excitation light sources for the photocatalytic material is very small, only about 4 to 10% of the visible light amount. In other words, most of natural light is occupied by visible light, and when conventional titanium oxide is used as a photocatalytic material, the visible light region occupying most of natural light cannot be used. Therefore, the light utilization efficiency is extremely low, especially in a room where the absolute amount of light is small, the function of the photocatalyst is not fully exhibited, and the indoor photocatalyst technology is hardly used and remains unused. It is no exaggeration to say that he was left alone.
しかしながら、近年では、光の絶対量が少ない室内空間においても機能しうる可視光応答型光触媒材料の開発が期待されつつあり、可視光領域の波長に対しても活性を示す各種光触媒材料が提案され、さかんに研究開発がおこなわれている。 However, in recent years, development of visible light responsive photocatalytic materials that can function even in an indoor space with a small absolute amount of light has been expected, and various photocatalytic materials that are active against wavelengths in the visible light region have been proposed. R & D is being carried out quickly.
たとえば、その一つに、酸化チタンにＣｒやＶなどの金属イオンをドープすることによって、可視光に対しても触媒活性を発現しうる触媒が提案されている（非特許文献１）。この提案によるとＣｒやＶなどの金属イオンがドープされることによって、酸化チタンの伝導帯と価電子帯の間にエネルギー準位が新たに作り出され、その結果、バンドギャップが狭くなり、確かに可視光を吸収することができるようになる。しかしながら、金属イオンのドープによって導入されたエネルギー準位は電子とホールの再結合準位にもなりえ、活性の上昇を期待できない場合が多い。 For example, as one of the catalysts, a catalyst that can exhibit catalytic activity even for visible light by doping titanium oxide with metal ions such as Cr and V has been proposed (Non-patent Document 1). According to this proposal, by doping metal ions such as Cr and V, a new energy level is created between the conduction band and the valence band of titanium oxide, and as a result, the band gap is narrowed. Visible light can be absorbed. However, the energy level introduced by doping metal ions can also be a recombination level of electrons and holes, and in many cases, an increase in activity cannot be expected.
さらに、酸化チタンに窒素などのアニオンをドープすることによって可視光応答型光触媒材料を作製することが提案されている（特許文献１）。この提案による酸化チタン光触媒は、金属イオンドープ型光触媒よりも確かに可視光照射下における活性は上昇するが、窒素をドープすることによって酸化チタン内部に酸素欠陥が作製され、光触媒活性が低下してしまうという欠点があった。また、何れにしてもドープという手法を用いることによって作製された可視光応答型光触媒材料は、現段階ではその活性はまだ不十分であり、更に一段と高いレベルの光触媒活性を発現しうる材料が求められている。 Furthermore, it has been proposed to produce a visible light responsive photocatalytic material by doping titanium oxide with an anion such as nitrogen (Patent Document 1). The titanium oxide photocatalyst produced by this proposal certainly increases the activity under visible light irradiation than the metal ion doped photocatalyst, but doping with nitrogen creates an oxygen defect inside the titanium oxide, reducing the photocatalytic activity. There was a drawback of end. In any case, the visible light responsive photocatalyst material produced by using the dope method is still insufficient at the present stage, and there is a demand for a material that can express a higher level of photocatalytic activity. It has been.
これに対し、非ドープ型の複合型酸化物光触媒は有効な可視光応答型光触媒材料であることが報告されている。最近では、酸化チタン以外の酸化物を利用した可視光応答型光触媒を作製する試みもなされている。たとえば、ＢｉＶＯ４は可視光照射下において硝酸銀水溶液から酸素を生成する光触媒材料であると報告されている（非特許文献２）。しかし、この材料は有機物に対する酸化力が不足しており、４−ノニルフェノールといった有機物を分解して二酸化炭素にまで完全に酸化分解することができない（非特許文献３）。すなわち、価電子帯のトップのポテンシャルが小さすぎて、有機物を完全に酸化分解することができないことが示唆されている。 On the other hand, it has been reported that an undoped complex oxide photocatalyst is an effective visible light responsive photocatalyst material. Recently, an attempt has been made to produce a visible light responsive photocatalyst using an oxide other than titanium oxide. For example, BiVO 4 is reported to be a photocatalytic material that generates oxygen from an aqueous silver nitrate solution under irradiation with visible light (Non-patent Document 2). However, this material has insufficient oxidizing power for organic matter, and cannot decompose organic matter such as 4-nonylphenol and completely oxidize and decompose it to carbon dioxide (Non-patent Document 3). That is, it is suggested that the top potential of the valence band is too small to completely oxidize and decompose organic matter.
また、ＡｇＮｂＯ３はバンドギャップが２．８ｅＶと可視光を吸収する特性をもち、実際、有機物を二酸化炭素にまで完全に酸化分解する特性を持つ材料である。しかし、固相法やゾルーゲル法など、一般的に利用されている材料作製方法では結晶性が悪く、単相の材料が作製しづらい。また、そのためか比較的比表面積が小さくなってしまう場合が多く、可視光での光触媒活性がそれほど高くないことが報告されている（非特許文献４）。 AgNbO 3 has a band gap of 2.8 eV and absorbs visible light. In fact, AgNbO 3 is a material that completely oxidizes and decomposes organic substances to carbon dioxide. However, a generally used material manufacturing method such as a solid phase method or a sol-gel method has poor crystallinity and it is difficult to manufacture a single-phase material. For this reason, the specific surface area often becomes relatively small, and it has been reported that the photocatalytic activity in visible light is not so high (Non-patent Document 4).
以上述べたように、近年、太陽光や室内照明に含まれているエネルギーの高い紫外光以外にも、これよりエネルギーの低い、波長の長い可視光領域の光に対して触媒活性を有する、光スペクトルを効率よく利用し得る光触媒、すなわち、紫外線、可視光線の両方に対しても高い活性を示す可視光応答型光触媒を希求する研究が活発に行われている。とりわけ、容易に入手しえる酸化物によって調製され、酸化チタンあるいはドープ型酸化チタンあるいは既存の可視光応答型光触媒材料の触媒活性と比較して遜色のない、あるいはこれを上回る触媒活性を有する可視光応答性光触媒が求められている。本発明は、この要請に応えようというものである。さらには、光を照射することによって有害物質を酸化、還元、分解する、有害物質の無害化処理、あるいは汚れの清浄化さらには抗菌特性に供する光触媒材料とこの触媒を用いた有害物質の無害化処理方法、あるいは汚れ物質分解清浄化方法さらには抗菌方法を提供しようと云うものである。特に、最近では光触媒を表面にコーティングし、そこに付着した汚れが光の作用あるいは光と表面の相互作用によって分解あるいは除去されるセルフクリーニング技術が注目されている。このようなセルフクリーニング技術に用いられる光触媒材料としては、良好な成膜性と環境に曝されても変質しない耐久性が要求されているが、本発明の汚れの清浄化に供せられる態様には、このようなセルフクリーニング技術による態様も含むものであり、この要請に対しても応えようというものである。 As described above, in addition to the high-energy ultraviolet light contained in sunlight and indoor lighting in recent years, light that has catalytic activity for light in the visible light region with a lower energy and longer wavelength than this. Research has been actively conducted to find a photocatalyst that can efficiently use the spectrum, that is, a visible light responsive photocatalyst exhibiting high activity against both ultraviolet rays and visible light. In particular, visible light that is prepared by readily available oxides and has a catalytic activity comparable or superior to that of titanium oxide or doped titanium oxide or existing visible light responsive photocatalytic materials There is a need for a responsive photocatalyst. The present invention seeks to meet this need. Furthermore, it oxidizes, reduces, and decomposes harmful substances by irradiating light, detoxifies harmful substances, or cleans dirt, and also detoxifies harmful substances using this catalyst for antibacterial properties. The present invention intends to provide a treatment method, a method for decomposing and cleaning dirt substances, and an antibacterial method. In particular, recently, a self-cleaning technique in which a photocatalyst is coated on the surface and dirt adhered thereto is decomposed or removed by the action of light or the interaction between light and the surface has attracted attention. As a photocatalyst material used in such a self-cleaning technique, good film formability and durability that does not change even when exposed to the environment are required. This includes such a self-cleaning technique and is intended to meet this demand.
そのため本発明者等においては、様々な材料について鋭意研究を重ねてきた。その結果、本発明者等は、銀とニオブ、アルカリ金属元素とからなる、一般式；ＡｇｘＭ１−ｘＮｂＯ３（Ｍは、１価の金属元素を示す。具体的にはＬｉ、Ｎａ、Ｋ、Ｒｂ、Ｃｓ、Ｃｕから選ばれる１種または２種以上のアルカリ金属元素）で示される固溶体材料が可視光照射下において優れた光触媒特性を持ち、ＡｇＮｂＯ３よりも可視光照射下における光触媒活性が大いに向上することを見出した。
本発明は、この知見に基づいてなされたものである。その構成は、以下に記載するとおりである。
For this reason, the present inventors have conducted extensive research on various materials. As a result, the inventors of the present invention have a general formula; Ag x M 1-x NbO 3 (M is a monovalent metal element composed of silver, niobium, and an alkali metal element. Specifically, Li, Na , K, Rb, Cs, Cu selected from a solid solution material having excellent photocatalytic properties under visible light irradiation, and a photocatalyst under visible light irradiation than AgNbO 3 It was found that the activity was greatly improved.
The present invention has been made based on this finding. The configuration is as described below.
一般式；ＡｇｘＭ１−ｘＮｂＯ３（０＜ｘ＜１、M：Mは１価の金属を示す。具体的にはＬｉ、Ｎａ、Ｋ、Ｒｂ、Ｃｓ、Ｃｕの１つ以上の金属元素からなる。）で表される組成を有する複合酸化物固溶体半導体からなることを特徴とする、可視光応答性光触媒。 General formula: Ag x M 1-x NbO 3 (0 <x <1, M: M represents a monovalent metal. Specifically, one or more metals of Li, Na, K, Rb, Cs, Cu A visible light responsive photocatalyst comprising a complex oxide solid solution semiconductor having a composition represented by:
本発明は、銀とその他の１価の金属元素、ニオブ、酸素とからなる複合酸化物半導体からなる光触媒であって、光を照射すると可視光領域の波長のスペクトルを十分に吸収することができ、これまで実用化されてきた酸化チタンをベースとした紫外光応答型光触媒に比して、極めて優位性を持つ材料である。また、ＣｒやＮをドープした材料に比べても、欠陥量が少なく、電子とホールの再結合も起こりづらく、光触媒活性も高い。本発明によれば、紫外光のみならず、可視光を利用して、工場などで最もよく利用されているＶＯＣの１種、２−プロピルアルコール（ＩＰＡ）を効率よく分解できる格別の効果を有してなるものである。この光触媒の特性はこれだけにとどまらず、光を照射することによってその他の有害ガス、たとえば、シックハウス症候群の原因ガスの１つであるアルデヒドガスや環境ホルモンなどの様々な有害物質を分解、除去することができる能力を有している。また、ウィルスや細菌に対しても抗ウィルス、抗菌効果を期待できる。本発明の複合酸化物半導体光触媒は、可視光、紫外光領域に対して活性を有することは上記の通りであり、その特性の故、前示した使用例以外にも多様な用途に利用できることが期待され、今後その果たす役割は、非常に大きいものと考えられる。さらにまた、その触媒性能は、前述した可視光応答性光触媒に比しても、本発明の光触媒能は優るとも劣ることはない。 The present invention is a photocatalyst composed of a composite oxide semiconductor composed of silver and other monovalent metal elements, niobium, and oxygen, and can sufficiently absorb the wavelength spectrum in the visible light region when irradiated with light. The material is extremely superior to the titanium oxide-based ultraviolet light-responsive photocatalyst that has been put to practical use. Also, compared to materials doped with Cr or N, the amount of defects is small, recombination of electrons and holes hardly occurs, and photocatalytic activity is high. According to the present invention, not only ultraviolet light but also visible light can be used to effectively decompose one type of VOC, 2-propyl alcohol (IPA), which is most often used in factories and the like. It is made. This photocatalyst is not limited to this, but it also decomposes and removes other harmful gases, such as aldehyde gas and environmental hormones, which are one of the cause gases of sick house syndrome, by irradiating light. Has the ability to Antiviral and antibacterial effects can also be expected against viruses and bacteria. As described above, the composite oxide semiconductor photocatalyst of the present invention has activity in the visible light and ultraviolet light regions, and because of its characteristics, it can be used in various applications other than the use examples shown above. Expected and expected to play a very important role in the future. Furthermore, the catalytic performance of the present invention is not inferior or inferior to the visible light responsive photocatalyst described above.
本発明の可視光領域においても触媒活性を示す優れた光触媒機能の発現は、ＡｇＮｂＯ３とＭＮｂＯ３との単純混合物化では説明できない現象であり、固溶体の形成が極めて重要であると考えられ、固溶体の形成を抜きにしては考えられない。すなわち、固溶体の形成は、より大きな光触媒活性をもたらすためのキーポイントであるといえる。これは固溶体を形成したことにより、価電子帯のトップの位置を最適にすることができ、すなわち、可視光の吸収能力を保持しながら、十分な酸化力を保持でき、また、固溶体化により反応場である表面に到達するホールの量が増加したためであると考えられる。また、これらの材料は他のドーピング材料に比べて欠陥も少なく、再結合も起こりづらく、バンド構造的にも光に安定な光触媒材料であると考えられる。 The expression of an excellent photocatalytic function exhibiting catalytic activity even in the visible light region of the present invention is a phenomenon that cannot be explained by a simple mixture of AgNbO 3 and MNbO 3, and the formation of a solid solution is considered to be extremely important. Without thinking of the formation of That is, it can be said that the formation of a solid solution is a key point for providing a larger photocatalytic activity. By forming a solid solution, the top position of the valence band can be optimized, that is, sufficient oxidizing power can be maintained while maintaining the ability to absorb visible light, and the reaction can be achieved by solid solution. This is probably because the amount of holes reaching the surface of the field has increased. In addition, these materials are considered to be light-catalyzed photocatalytic materials that are less susceptible to recombination than other doping materials and are less susceptible to recombination.
本発明の光触媒としての複合酸化物固溶体半導体を得るためには、通常の固相反応法、すなわち原料となる各金属成分の酸化物あるいは金属炭酸塩あるいは金属硝酸塩あるいは金属硫酸塩、あるいは金属塩化物を目的組成の比率で混合し、常圧下空気中で焼成することによって合成することができる。また、焼成の際、原料成分によっては、昇華し、触媒の材料設計に、計画された設計とはズレが生ずることもあるが、この場合、昇華に見合う量を最初から多めに加えておくことによって対処することができる。また、上記原料以外に金属アルコキシドや金属塩を原料とし、これをいわゆるゾルーゲル法、共沈法、錯体重合法、スパッタリング法、化学蒸着法、水熱合成法などといった様々な方法によって調製することができ、何れの調製プロセスによっても実施可能である。調整された配合原料を焼成する際の焼成温度は、原料物質が分解して酸化物に転換され、酸化物からなる焼結体が得られる温度であればよい。 In order to obtain a composite oxide solid solution semiconductor as a photocatalyst of the present invention, an ordinary solid phase reaction method, that is, an oxide, metal carbonate, metal nitrate, metal sulfate, or metal chloride of each metal component as a raw material Can be synthesized by mixing at a ratio of the desired composition and firing in air under normal pressure. Also, depending on the raw material components during firing, the material design of the catalyst may deviate from the planned design, but in this case, add an amount appropriate for sublimation from the beginning. Can be dealt with by. In addition to the above raw materials, a metal alkoxide or a metal salt can be used as a raw material, which can be prepared by various methods such as so-called sol-gel method, coprecipitation method, complex polymerization method, sputtering method, chemical vapor deposition method, hydrothermal synthesis method and the like. It can be carried out by any preparation process. The firing temperature at which the adjusted blended raw material is fired may be any temperature at which the raw material is decomposed and converted into an oxide to obtain a sintered body made of the oxide.
本発明の光触媒の形状、粒径は、光を有効に利用するためにできるだけ表面積が大きくなるように設計されることが望ましい。固相反応法によって作製した複合酸化物光触媒は、大きな成型物あるいは塊状物として得られるため、これをボールミルなどで粉砕するか、あるいは酸などでエッチングすることによってさらに表面積を大きくすることができる。また、メソポーラス構造になるように合成して、表面積を大きくしてもよい。さらに、粉末粒子を適宜大きさの形状、形態に成形して使用することもできる。本発明の光触媒は、焼結法以外にも、前述記載した様々な調整手段が利用でき、たとえば、触媒成分を含む水溶液等の反応原料溶液を用意し、反応溶液から共析反応、あるいは共沈反応によって、触媒成分を含む物質を共析、共沈させ、それらをさらに乾燥脱水あるいは焼成することによっても作製することができる。 The shape and particle size of the photocatalyst of the present invention are desirably designed so that the surface area becomes as large as possible in order to effectively use light. Since the composite oxide photocatalyst produced by the solid phase reaction method is obtained as a large molded product or a lump, the surface area can be further increased by pulverizing it with a ball mill or etching with an acid or the like. Further, the surface area may be increased by synthesizing so as to have a mesoporous structure. Furthermore, it is possible to use the powder particles by appropriately shaping them into a shape and shape. The photocatalyst of the present invention can use the various adjusting means described above in addition to the sintering method. For example, a reaction raw material solution such as an aqueous solution containing a catalyst component is prepared, and a eutectoid reaction or coprecipitation is performed from the reaction solution. It can also be produced by co-depositing and co-precipitating a substance containing a catalyst component by reaction and further drying or dehydrating or calcining them.
本発明の光触媒材料の光触媒反応により分解あるいは酸化あるいは還元反応により除去できる有害物質としては環境ホルモン、農薬、殺虫剤、カビ、細菌、ウィルス、藻類、環境汚染物質、フロンガス、炭化水素、アルコール、アルデヒド、ケトン、カルボン酸、一酸化炭素、アミン、油、芳香族化合物、有機ハロゲン化合物、窒素化合物、硫黄化合物、有機リン化合物、蛋白質などが挙げられる。さらに身の回りの汚れの原因となっている石鹸や油、手垢、茶渋、台所のシンクなどのぬめりなどもこの光触媒材料の光触媒反応により分解できる。 Hazardous substances that can be decomposed or removed by oxidation or reduction reaction of the photocatalytic material of the present invention include environmental hormones, agricultural chemicals, insecticides, molds, bacteria, viruses, algae, environmental pollutants, chlorofluorocarbons, hydrocarbons, alcohols, aldehydes , Ketone, carboxylic acid, carbon monoxide, amine, oil, aromatic compound, organic halogen compound, nitrogen compound, sulfur compound, organic phosphorus compound, protein and the like. In addition, soap and oil, hand stains, tea astringents, and slimes such as kitchen sinks that cause personal contamination can be decomposed by the photocatalytic reaction of this photocatalytic material.
以下、本発明を具体的な実施例と図面に基づいて詳細に説明するが、これらは本発明を限定するものではない。以下の実施例においては、一般式；ＡｇｘＭ１−ｘＮｂＯ３（０＜ｘ＜１、M：Mは１価の金属を示す。具体的にはＬｉ、Ｎａ、Ｋ、Ｒｂ、Ｃｓ、Ｃｕの１つ以上の金属元素からなる。）で示される複合酸化物固溶体半導体光触媒を実施例として開示し、これを固相反応法で合成した場合の実施例である。繰り返すが、この実施例は、あくまでも本発明を具体的に説明するための一つの実施例であって、本発明は、この実施例によって限定されるものでない。 Hereinafter, although the present invention is explained in detail based on a concrete example and a drawing, these do not limit the present invention. In the following examples, a general formula: Ag x M 1-x NbO 3 (0 <x <1, M: M represents a monovalent metal. Specifically, Li, Na, K, Rb, Cs, The composite oxide solid solution semiconductor photocatalyst represented by 1 or more of Cu is disclosed as an example, and this is an example in which this is synthesized by a solid phase reaction method. Again, this example is merely an example for specifically explaining the present invention, and the present invention is not limited to this example.
実施例１；
銀、ナトリウム、ニオブからなる複合酸化物固溶体半導体の１つであるＡｇ０．４Ｎａ０．６ＮｂＯ３を以下に述べるように固相反応法によって合成した。
先ず、酸化銀を０．９３ｇと炭酸ナトリウムを０．６４ｇ、酸化ニオブを２．６６ｇそれぞれ秤量した。これらをボールミルや乳鉢などの粉砕混合器具を利用して十分に粉砕混合したあと、アルミナるつぼに入れて、大気圧空気雰囲気下で９００℃にて１０時間焼結し、粉末を得た。また、必要ならば空気雰囲気に変えて酸素雰囲気で焼成をおこなってもよい。この粉末をＸ線回折装置を用いて、測定したところ、銀や酸化銀などの不純物相は確認されず、単相のＡｇ０．４Ｎａ０．６ＮｂＯ３固溶体が得られていることがわかった（図１）。紫外−可視吸収スペクトル測定の結果、本実施例の光触媒は紫外線領域から約４２０ｎｍ程度までの可視光領域まで吸収を示した（図２）。
Example 1;
Ag 0.4 Na 0.6 NbO 3 , which is one of complex oxide solid solution semiconductors composed of silver, sodium, and niobium, was synthesized by a solid phase reaction method as described below.
First, 0.93 g of silver oxide, 0.64 g of sodium carbonate, and 2.66 g of niobium oxide were weighed. These were sufficiently pulverized and mixed using a pulverizing and mixing device such as a ball mill and a mortar, then placed in an alumina crucible and sintered at 900 ° C. for 10 hours in an atmospheric air atmosphere to obtain a powder. Further, if necessary, firing may be performed in an oxygen atmosphere instead of an air atmosphere. When this powder was measured using an X-ray diffractometer, an impurity phase such as silver or silver oxide was not confirmed, and it was found that a single-phase Ag 0.4 Na 0.6 NbO 3 solid solution was obtained. (FIG. 1). As a result of ultraviolet-visible absorption spectrum measurement, the photocatalyst of this example showed absorption from the ultraviolet region to the visible light region of about 420 nm (FIG. 2).
実施例２；
実施例１で得られた０．４ｇのＡｇ０．４Ｎａ０．６ＮｂＯ３で約４００ｐｐｍの２−プロピルアルコールの分解試験を行った。光源には３００Ｗ Ｘｅランプを用い、カットオフフィルターを利用して、４００ｎｍから５２０ｎｍの可視光（光量：１．６ｍＷｃｍ−２）を反応容器に照射した。２−プロピルアルコールとその分解物質のアセトン、二酸化炭素の検出及び定量はメタナイザー付ガスクロマトグラフィー（検出器はＦＩＤ）で行い、２−プロピルアルコールを分解したときに生成する中間体アセトンの発生量の時間変化について調べた（図３）。その結果、８０分間の光照射で約７０ｐｐｍものアセトンが生成し、この材料は可視光応答型の光触媒であることが明らかになった。また、さらに長時間光照射すると、二酸化炭素にまで完全に酸化分解することも明らかになった。
Example 2;
A decomposition test of about 400 ppm of 2-propyl alcohol was conducted with 0.4 g of Ag 0.4 Na 0.6 NbO 3 obtained in Example 1. A 300 W Xe lamp was used as the light source, and the reaction vessel was irradiated with visible light (light amount: 1.6 mWcm −2 ) from 400 nm to 520 nm using a cutoff filter. Detection and quantification of 2-propyl alcohol and its decomposition substances acetone and carbon dioxide are performed by gas chromatography with a methanizer (detector is FID), and the amount of intermediate acetone generated when 2-propyl alcohol is decomposed is measured. The change with time was examined (FIG. 3). As a result, about 70 ppm of acetone was produced by light irradiation for 80 minutes, and it was revealed that this material is a visible light responsive photocatalyst. It was also revealed that when light was irradiated for a longer time, it was completely oxidatively decomposed to carbon dioxide.
実施例３；
銀、ナトリウム、ニオブからなる複合酸化物固溶体半導体の１つであるＡｇ０.７Ｎａ０．３ＮｂＯ３を以下に述べるように固相反応法によって合成した。
先ず、酸化銀を１．６２ｇと炭酸ナトリウムを０．４２ｇ、酸化ニオブを２．６６ｇそれぞれ秤量した。これらをボールミルや乳鉢などの粉砕混合器具を利用して十分に粉砕混合したあと、アルミナるつぼに入れて、大気圧空気雰囲気下で９００℃にて１０時間焼結し、粉末を得た。この粉末をＸ線回折装置を用いて、測定したところ、銀や酸化銀などの不純物相は確認されず、単相のＡｇ０.７Ｎａ０．３ＮｂＯ３固溶体が得られていることがわかった（図１）。紫外−可視吸収スペクトル測定の結果、本実施例の光触媒は紫外線領域から約４４０ｎｍ程度までの可視光領域まで吸収を示した（図２）
Example 3;
Ag 0.7 Na 0.3 NbO 3 , which is one of complex oxide solid solution semiconductors composed of silver, sodium, and niobium, was synthesized by a solid phase reaction method as described below.
First, 1.62 g of silver oxide, 0.42 g of sodium carbonate, and 2.66 g of niobium oxide were weighed. These were sufficiently pulverized and mixed using a pulverizer such as a ball mill or a mortar, then placed in an alumina crucible and sintered at 900 ° C. for 10 hours in an atmospheric air atmosphere to obtain a powder. When this powder was measured using an X-ray diffractometer, an impurity phase such as silver or silver oxide was not confirmed, and it was found that a single-phase Ag 0.7 Na 0.3 NbO 3 solid solution was obtained. (FIG. 1). As a result of ultraviolet-visible absorption spectrum measurement, the photocatalyst of this example showed absorption from the ultraviolet region to the visible light region up to about 440 nm (FIG. 2).
実施例４；
実施例１で得られた０．４ｇのＡｇ０.７Ｎａ０．３ＮｂＯ３で約４００ｐｐｍの２−プロピルアルコールの分解試験を行った。光源には３００Ｗ Ｘｅランプを用い、カットオフフィルターを利用して、４００ｎｍから５２０ｎｍの可視光（光量：１．６ｍＷｃｍ−２）を反応容器に照射し、２−プロピルアルコールを分解したときに生成する中間体アセトンの発生量の時間変化について調べた（図３）。その結果、８０分間の光照射で約４０ｐｐｍものアセトンが生成し、この材料は可視光応答型の光触媒であることが明らかになった。また、さらに長時間光照射すると、二酸化炭素にまで完全に酸化分解することも明らかになった。
Example 4;
A decomposition test of about 400 ppm of 2-propyl alcohol was performed with 0.4 g of Ag 0.7 Na 0.3 NbO 3 obtained in Example 1. A 300 W Xe lamp is used as the light source, and a visible light of 400 to 520 nm (light quantity: 1.6 mWcm −2 ) is irradiated to the reaction vessel using a cutoff filter, and generated when 2-propyl alcohol is decomposed. The time variation of the amount of intermediate acetone generated was examined (FIG. 3). As a result, about 40 ppm of acetone was produced by light irradiation for 80 minutes, and it was revealed that this material is a visible light responsive photocatalyst. It was also revealed that when light was irradiated for a longer time, it was completely oxidatively decomposed to carbon dioxide.
比較例１；
代表的な光触媒であるアナターゼ型ＴｉＯ２を利用して２−プロピルアルコール分解の可視光分解活性を調べた。測定に使用した機器は実施例２と同じであった。その結果、１時間経過してもアセトン、二酸化炭素の生成量はなく、気相中の２−プロピルアルコールの量に変化もないことから２−プロピルアルコールは、全く分解されないことが確認された（図３）。紫外光において優れた活性を示すＴｉＯ２も可視光照射においては活性を示さず、可視光領域における光触媒活性はＡｇｘＭ１−ｘＮｂＯ３（０＜ｘ＜１、M：Mは１価の金属を示す。具体的にはＬｉ、Ｎａ、Ｋ、Ｒｂ、Ｃｓ、Ｃｕの１つ以上の金属元素からなる。）よりも著しく劣っていた。以上のことから、このＴｉＯ２光触媒は、可視光照射下においては２−プロピルアルコールをはじめとする有機物を分解する能力がないことが再確認された。
Comparative Example 1;
The visible light decomposition activity of 2-propyl alcohol decomposition was investigated using anatase TiO 2 which is a typical photocatalyst. The equipment used for the measurement was the same as in Example 2. As a result, it was confirmed that 2-propyl alcohol was not decomposed at all since there was no production of acetone and carbon dioxide even after 1 hour, and there was no change in the amount of 2-propyl alcohol in the gas phase. FIG. 3). TiO 2 exhibiting excellent activity in ultraviolet light also does not show activity in visible light irradiation, and the photocatalytic activity in the visible light region is Ag x M 1-x NbO 3 (0 <x <1, M: M is monovalent) A metal, specifically composed of one or more metal elements of Li, Na, K, Rb, Cs, and Cu.). From the above, it was reconfirmed that this TiO 2 photocatalyst has no ability to decompose organic substances such as 2-propyl alcohol under irradiation with visible light.
比較例２；
代表的な可視光応答型光触媒であるＡｇＮｂＯ３を利用して２−プロピルアルコールの可視光分解活性を調べた。測定に使用した機器は実施例２と同じであった。その結果、１時間でアセトンが約２０ｐｐｍ生成することが確認され、実施例２、４と比較した場合、光触媒活性は約２倍以上劣っていることがわかった（図３）。このように銀、その他の１価の金属、ニオブからなる複合酸化物半導体は既存の可視光応答型材料よりも高い活性を持っており、非常に有効な可視光応答型の光触媒材料であることがわかる。
Comparative Example 2;
The visible light decomposition activity of 2-propyl alcohol was examined using AgNbO 3 which is a typical visible light responsive photocatalyst. The equipment used for the measurement was the same as in Example 2. As a result, it was confirmed that about 20 ppm of acetone was produced in 1 hour, and it was found that the photocatalytic activity was inferior by about twice or more when compared with Examples 2 and 4 (FIG. 3). Thus, the composite oxide semiconductor composed of silver, other monovalent metals, and niobium has a higher activity than existing visible light responsive materials, and is a very effective visible light responsive photocatalyst material. I understand.
以上の結果について、図１―３に示していることは、前述したとおりである。また、上記実施例以外にもぺロブスカイト構造を持つＡｇ０．５Ｋ０．５ＮｂＯ３などは可視光に吸収を示し、可視光照射下で有機物を効率よく分解する。
すなわち、銀、その他の１価の金属、ニオブからなる複合酸化物半導体は高活性な可視光応答型光触媒材料であり、前述の目的に沿う材料の開発に成功したことを示している。これによって、照射される光の波長に対して、利用効率が高まり、光触媒反応に一層有効に利用され、寄与するものと期待される。
The above results are shown in FIG. 1-3 as described above. In addition to the above examples, Ag 0.5 K 0.5 NbO 3 having a perovskite structure absorbs visible light and efficiently decomposes organic substances under visible light irradiation.
In other words, a composite oxide semiconductor composed of silver, other monovalent metals, and niobium is a highly active visible light responsive photocatalytic material, indicating that the material has been successfully developed in accordance with the above-mentioned purpose. As a result, the use efficiency is increased with respect to the wavelength of the irradiated light, and it is expected to be more effectively utilized and contribute to the photocatalytic reaction.
以上説明してきたように、本発明は、一般式；ＡｇｘＭ１−ｘＮｂＯ３（０＜ｘ＜１、Ｍ：Ｍは１価の金属を示す。具体的にはＬｉ、Ｎａ、Ｋ、Ｒｂ、Ｃｓ、Ｃｕの１つ以上の金属元素からなる。）固溶体半導体光触媒は、紫外光のみならず、十分に可視光まで吸収できる。本発明によって、これまでの実用光触媒、ＴｉＯ２が、紫外光領域でのみ機能していたことを考えると、有効利用できる波長領域を大きく広げることができたという意義は極めて大きい。また、可視光領域においても既存のＡｇＮｂＯ３よりも活性が高い。本発明によれば、可視光を利用して各種有害な化合物、例えば、環境ホルモンや細菌等いわゆる有害物質に作用し、これらを殺菌、分解、除去等無害化するのに使用される環境対策技術を始めとして各種化学反応に大いに利用され、産業の発展に寄与するものと期待される。 As described above, the present invention has the general formula: Ag x M 1-x NbO 3 (0 <x <1, M: M represents a monovalent metal. Specifically, Li, Na, K, It consists of one or more metal elements of Rb, Cs, and Cu.) The solid solution semiconductor photocatalyst can absorb not only ultraviolet light but also visible light. Considering that the present practical photocatalyst, TiO 2 , functioned only in the ultraviolet light region according to the present invention, it is extremely significant that the wavelength region that can be effectively used can be greatly expanded. Moreover, the activity is higher than that of the existing AgNbO 3 in the visible light region. According to the present invention, environmental countermeasure technology used to make various harmful compounds using visible light, such as environmental hormones and bacteria, so-called harmful substances, sterilize, decompose, remove, etc. It is expected to contribute to the development of industry by being used for various chemical reactions.
Claims (1)
General formula; Ag x M 1-x NbO 3 (0 <x <1, M represents a monovalent metal element. Specifically, one or more metal elements of Li, Na, K, Rb, Cs, Cu A visible light-responsive photocatalyst comprising a composite oxide solid solution semiconductor having a composition represented by:
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2006176577A JP2008006328A (en) | 2006-06-27 | 2006-06-27 | Photocatalyst comprising visible light responsive composite oxide semiconductor |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2006176577A JP2008006328A (en) | 2006-06-27 | 2006-06-27 | Photocatalyst comprising visible light responsive composite oxide semiconductor |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JP2008006328A true JP2008006328A (en) | 2008-01-17 |
Family
ID=39065030
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP2006176577A Pending JP2008006328A (en) | 2006-06-27 | 2006-06-27 | Photocatalyst comprising visible light responsive composite oxide semiconductor |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP2008006328A (en) |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN109794243A (en) * | 2019-01-18 | 2019-05-24 | 陕西科技大学 | A kind of Ag with excellent photocatalysis performance2O/AgNbO3Powder and preparation method thereof |
| CN114177928A (en) * | 2021-12-27 | 2022-03-15 | 吉林大学 | Composite photocatalyst Bi @ H-TiO with visible light response2/B-C3N4Preparation method and application thereof |
| CN114455664A (en) * | 2021-07-20 | 2022-05-10 | 杭州同晨环保科技有限公司 | Visible light illumination enhanced type sterilization and decoloration dual-function water treatment agent |
-
2006
- 2006-06-27 JP JP2006176577A patent/JP2008006328A/en active Pending
Cited By (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN109794243A (en) * | 2019-01-18 | 2019-05-24 | 陕西科技大学 | A kind of Ag with excellent photocatalysis performance2O/AgNbO3Powder and preparation method thereof |
| CN109794243B (en) * | 2019-01-18 | 2021-12-21 | 陕西科技大学 | Ag with excellent photocatalytic performance2O/AgNbO3Powder and preparation method thereof |
| CN114455664A (en) * | 2021-07-20 | 2022-05-10 | 杭州同晨环保科技有限公司 | Visible light illumination enhanced type sterilization and decoloration dual-function water treatment agent |
| CN114455664B (en) * | 2021-07-20 | 2024-02-20 | 茂名众和国颂水处理技术有限公司 | Visible light enhanced sterilization and decoloration dual-functional water treatment agent |
| CN114177928A (en) * | 2021-12-27 | 2022-03-15 | 吉林大学 | Composite photocatalyst Bi @ H-TiO with visible light response2/B-C3N4Preparation method and application thereof |
| CN114177928B (en) * | 2021-12-27 | 2023-10-03 | 吉林大学 | Composite photocatalyst Bi@H-TiO with visible light response 2 /B-C 3 N 4 Preparation method and application thereof |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| JP6342225B2 (en) | Photocatalyst composite material and method for producing the same | |
| Zaleska | Doped-TiO2: a review | |
| KR100945035B1 (en) | Tungstates based visible-light induced oxides photocatalysts and synthesis methods thereof | |
| TWI476043B (en) | Photocatalytic materials and process for producing the same | |
| JP2009078211A (en) | Photocatalyst | |
| JP6995334B2 (en) | Photocatalyst and how to use it | |
| JP2007216223A (en) | Photocatalytic material having semiconductor properties, and its manufacturing method and use | |
| Anandan et al. | [Retracted] Highly Active Rare‐Earth‐Metal La‐Doped Photocatalysts: Fabrication, Characterization, and Their Photocatalytic Activity | |
| Mohamed et al. | Mesoporous BiVO4/2D-g-C3N4 heterostructures for superior visible light-driven photocatalytic reduction of Hg (II) ions | |
| JP6552090B2 (en) | Photocatalyst composite material and method for producing the same | |
| Hu et al. | One‐Step Cohydrothermal Synthesis of Nitrogen‐Doped Titanium Oxide Nanotubes with Enhanced Visible Light Photocatalytic Activity | |
| JP4871325B2 (en) | PHOTOCATALYST AGENT HAVING TITANIUM OXIDE / IRON TITANATE JOINT STRUCTURE AND METHOD FOR PRODUCING THE SAME | |
| JP4997627B2 (en) | Visible light responsive photocatalyst | |
| Truong et al. | A critical innovation of photocatalytic degradation for toxic chemicals and pathogens in air | |
| WO2005087371A1 (en) | Photocatalyst based on composite oxide responsive to visible light and method for decomposition and removal of harmful chemical material using the same | |
| Salmanzadeh-Jamadi et al. | Facile fabrication of TiO2/Bi5O7Br photocatalysts for visible-light-assisted removal of tetracycline and dye wastewaters | |
| JP2007098293A (en) | Visible light response type photocatalyst, visible light response type photocatalyst composition and its production method | |
| JP2003019437A (en) | Photocatalyst, method for producing hydrogen using the photocatalyst, and method for decomposing harmful matter | |
| JP2008006328A (en) | Photocatalyst comprising visible light responsive composite oxide semiconductor | |
| KR20200126593A (en) | Fe-doped perovskite photocatalyst, its preparation method and environmental pollution control using it | |
| JP4660766B2 (en) | Visible light responsive complex oxide photocatalyst | |
| Ansari et al. | Perovskite-type catalytic materials for water treatment | |
| JP2015100755A (en) | Photocatalyst material and method for producing the same | |
| Yang et al. | Review of N and metal co-doped TiO2 for water purification under visible light irradiation | |
| KR101242576B1 (en) | Photocatalyst having a tin oxide with metal ion and titanium dioxide composite structure and preparation method thereof |