JPH08283022A - Titanium dioxide based composite superfine particle and its production - Google Patents
Titanium dioxide based composite superfine particle and its productionInfo
- Publication number
- JPH08283022A JPH08283022A JP7109172A JP10917295A JPH08283022A JP H08283022 A JPH08283022 A JP H08283022A JP 7109172 A JP7109172 A JP 7109172A JP 10917295 A JP10917295 A JP 10917295A JP H08283022 A JPH08283022 A JP H08283022A
- Authority
- JP
- Japan
- Prior art keywords
- ultrafine particles
- tio
- particles
- composite
- oxygen
- 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
- 239000002131 composite material Substances 0.000 title claims abstract description 72
- GWEVSGVZZGPLCZ-UHFFFAOYSA-N Titan oxide Chemical compound O=[Ti]=O GWEVSGVZZGPLCZ-UHFFFAOYSA-N 0.000 title claims abstract description 44
- 239000002245 particle Substances 0.000 title claims abstract description 38
- 238000004519 manufacturing process Methods 0.000 title claims description 12
- 239000004408 titanium dioxide Substances 0.000 title 1
- 238000000034 method Methods 0.000 claims abstract description 35
- 239000012298 atmosphere Substances 0.000 claims abstract description 34
- 229910052751 metal Inorganic materials 0.000 claims abstract description 24
- 239000002184 metal Substances 0.000 claims abstract description 24
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 claims abstract description 20
- 239000001301 oxygen Substances 0.000 claims abstract description 20
- 229910052760 oxygen Inorganic materials 0.000 claims abstract description 20
- IJGRMHOSHXDMSA-UHFFFAOYSA-N Atomic nitrogen Chemical compound N#N IJGRMHOSHXDMSA-UHFFFAOYSA-N 0.000 claims abstract description 16
- 229910052763 palladium Inorganic materials 0.000 claims abstract description 16
- 239000011261 inert gas Substances 0.000 claims abstract description 15
- 239000002994 raw material Substances 0.000 claims abstract description 13
- 229910052697 platinum Inorganic materials 0.000 claims abstract description 11
- 229910052707 ruthenium Inorganic materials 0.000 claims abstract description 8
- 229910052757 nitrogen Inorganic materials 0.000 claims abstract description 7
- 229910052703 rhodium Inorganic materials 0.000 claims abstract description 7
- 229910052709 silver Inorganic materials 0.000 claims abstract description 7
- 229910052737 gold Inorganic materials 0.000 claims abstract description 6
- 229910052759 nickel Inorganic materials 0.000 claims abstract description 6
- 229910052802 copper Inorganic materials 0.000 claims abstract description 4
- 239000010419 fine particle Substances 0.000 claims abstract description 3
- 239000011882 ultra-fine particle Substances 0.000 claims description 154
- 229910010413 TiO 2 Inorganic materials 0.000 claims description 71
- 239000007789 gas Substances 0.000 claims description 28
- 239000000956 alloy Substances 0.000 claims description 23
- 229910045601 alloy Inorganic materials 0.000 claims description 23
- 229910001873 dinitrogen Inorganic materials 0.000 claims description 6
- 229910052742 iron Inorganic materials 0.000 claims description 6
- 229910052799 carbon Inorganic materials 0.000 claims description 4
- 150000001875 compounds Chemical class 0.000 claims description 3
- 239000000919 ceramic Substances 0.000 claims description 2
- 239000000203 mixture Substances 0.000 abstract description 10
- 238000010438 heat treatment Methods 0.000 abstract description 9
- 230000000694 effects Effects 0.000 abstract description 8
- 230000001699 photocatalysis Effects 0.000 abstract description 4
- 230000008018 melting Effects 0.000 description 22
- 238000002844 melting Methods 0.000 description 22
- KDLHZDBZIXYQEI-UHFFFAOYSA-N Palladium Chemical compound [Pd] KDLHZDBZIXYQEI-UHFFFAOYSA-N 0.000 description 20
- 239000003054 catalyst Substances 0.000 description 20
- 239000000843 powder Substances 0.000 description 18
- 239000010936 titanium Substances 0.000 description 18
- MYMOFIZGZYHOMD-UHFFFAOYSA-N Dioxygen Chemical compound O=O MYMOFIZGZYHOMD-UHFFFAOYSA-N 0.000 description 15
- 229910001882 dioxygen Inorganic materials 0.000 description 15
- 239000004065 semiconductor Substances 0.000 description 15
- BASFCYQUMIYNBI-UHFFFAOYSA-N platinum Chemical compound [Pt] BASFCYQUMIYNBI-UHFFFAOYSA-N 0.000 description 13
- 238000000354 decomposition reaction Methods 0.000 description 9
- 239000011941 photocatalyst Substances 0.000 description 9
- 230000003197 catalytic effect Effects 0.000 description 8
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 8
- 238000002441 X-ray diffraction Methods 0.000 description 7
- 230000000844 anti-bacterial effect Effects 0.000 description 7
- OKKJLVBELUTLKV-UHFFFAOYSA-N Methanol Chemical compound OC OKKJLVBELUTLKV-UHFFFAOYSA-N 0.000 description 6
- 239000012535 impurity Substances 0.000 description 6
- 239000007791 liquid phase Substances 0.000 description 6
- 229910052719 titanium Inorganic materials 0.000 description 6
- CURLTUGMZLYLDI-UHFFFAOYSA-N Carbon dioxide Chemical compound O=C=O CURLTUGMZLYLDI-UHFFFAOYSA-N 0.000 description 4
- RTAQQCXQSZGOHL-UHFFFAOYSA-N Titanium Chemical compound [Ti] RTAQQCXQSZGOHL-UHFFFAOYSA-N 0.000 description 4
- 230000005540 biological transmission Effects 0.000 description 4
- 238000010586 diagram Methods 0.000 description 4
- UFHFLCQGNIYNRP-UHFFFAOYSA-N Hydrogen Chemical compound [H][H] UFHFLCQGNIYNRP-UHFFFAOYSA-N 0.000 description 3
- 239000007864 aqueous solution Substances 0.000 description 3
- 238000006243 chemical reaction Methods 0.000 description 3
- 230000001747 exhibiting effect Effects 0.000 description 3
- 239000010931 gold Substances 0.000 description 3
- 239000001257 hydrogen Substances 0.000 description 3
- 229910052739 hydrogen Inorganic materials 0.000 description 3
- 239000002923 metal particle Substances 0.000 description 3
- 230000003647 oxidation Effects 0.000 description 3
- 238000007254 oxidation reaction Methods 0.000 description 3
- 239000010948 rhodium Substances 0.000 description 3
- 239000010944 silver (metal) Substances 0.000 description 3
- 238000000629 steam reforming Methods 0.000 description 3
- 230000001954 sterilising effect Effects 0.000 description 3
- 238000004659 sterilization and disinfection Methods 0.000 description 3
- 239000000126 substance Substances 0.000 description 3
- 239000012808 vapor phase Substances 0.000 description 3
- 241000894006 Bacteria Species 0.000 description 2
- LFQSCWFLJHTTHZ-UHFFFAOYSA-N Ethanol Chemical compound CCO LFQSCWFLJHTTHZ-UHFFFAOYSA-N 0.000 description 2
- 238000003917 TEM image Methods 0.000 description 2
- 239000004566 building material Substances 0.000 description 2
- 229910002092 carbon dioxide Inorganic materials 0.000 description 2
- 239000001569 carbon dioxide Substances 0.000 description 2
- 239000007809 chemical reaction catalyst Substances 0.000 description 2
- 235000009508 confectionery Nutrition 0.000 description 2
- 230000018044 dehydration Effects 0.000 description 2
- 238000006297 dehydration reaction Methods 0.000 description 2
- 238000006356 dehydrogenation reaction Methods 0.000 description 2
- 238000001514 detection method Methods 0.000 description 2
- 239000007788 liquid Substances 0.000 description 2
- 239000002905 metal composite material Substances 0.000 description 2
- 230000033116 oxidation-reduction process Effects 0.000 description 2
- 239000012071 phase Substances 0.000 description 2
- TXUICONDJPYNPY-UHFFFAOYSA-N (1,10,13-trimethyl-3-oxo-4,5,6,7,8,9,11,12,14,15,16,17-dodecahydrocyclopenta[a]phenanthren-17-yl) heptanoate Chemical compound C1CC2CC(=O)C=C(C)C2(C)C2C1C1CCC(OC(=O)CCCCCC)C1(C)CC2 TXUICONDJPYNPY-UHFFFAOYSA-N 0.000 description 1
- 241000186361 Actinobacteria <class> Species 0.000 description 1
- 229910018072 Al 2 O 3 Inorganic materials 0.000 description 1
- 241000195493 Cryptophyta Species 0.000 description 1
- 244000061176 Nicotiana tabacum Species 0.000 description 1
- 235000002637 Nicotiana tabacum Nutrition 0.000 description 1
- 240000004808 Saccharomyces cerevisiae Species 0.000 description 1
- 229910002367 SrTiO Inorganic materials 0.000 description 1
- 229910021626 Tin(II) chloride Inorganic materials 0.000 description 1
- 239000002253 acid Substances 0.000 description 1
- 239000004480 active ingredient Substances 0.000 description 1
- 150000001298 alcohols Chemical class 0.000 description 1
- 239000003242 anti bacterial agent Substances 0.000 description 1
- 230000000843 anti-fungal effect Effects 0.000 description 1
- 239000003429 antifungal agent Substances 0.000 description 1
- 229940121375 antifungal agent Drugs 0.000 description 1
- 244000052616 bacterial pathogen Species 0.000 description 1
- 230000015572 biosynthetic process Effects 0.000 description 1
- 238000006555 catalytic reaction Methods 0.000 description 1
- 230000022534 cell killing Effects 0.000 description 1
- 239000011248 coating agent Substances 0.000 description 1
- 238000000576 coating method Methods 0.000 description 1
- 238000004332 deodorization Methods 0.000 description 1
- 230000001877 deodorizing effect Effects 0.000 description 1
- 238000000151 deposition Methods 0.000 description 1
- 238000010891 electric arc Methods 0.000 description 1
- 238000003411 electrode reaction Methods 0.000 description 1
- 238000010894 electron beam technology Methods 0.000 description 1
- 230000008020 evaporation Effects 0.000 description 1
- 238000001704 evaporation Methods 0.000 description 1
- 239000005357 flat glass Substances 0.000 description 1
- 239000011521 glass Substances 0.000 description 1
- 230000006698 induction Effects 0.000 description 1
- 230000001678 irradiating effect Effects 0.000 description 1
- 238000004898 kneading Methods 0.000 description 1
- 239000000463 material Substances 0.000 description 1
- 150000002739 metals Chemical class 0.000 description 1
- 244000005700 microbiome Species 0.000 description 1
- 210000000214 mouth Anatomy 0.000 description 1
- 239000012299 nitrogen atmosphere Substances 0.000 description 1
- 229910000510 noble metal Inorganic materials 0.000 description 1
- 238000006864 oxidative decomposition reaction Methods 0.000 description 1
- 239000003973 paint Substances 0.000 description 1
- PIBWKRNGBLPSSY-UHFFFAOYSA-L palladium(II) chloride Chemical compound Cl[Pd]Cl PIBWKRNGBLPSSY-UHFFFAOYSA-L 0.000 description 1
- 238000002256 photodeposition Methods 0.000 description 1
- 231100000614 poison Toxicity 0.000 description 1
- 230000007096 poisonous effect Effects 0.000 description 1
- 238000000550 scanning electron microscopy energy dispersive X-ray spectroscopy Methods 0.000 description 1
- 239000000779 smoke Substances 0.000 description 1
- 235000011150 stannous chloride Nutrition 0.000 description 1
- 239000001119 stannous chloride Substances 0.000 description 1
- 239000007858 starting material Substances 0.000 description 1
- VEALVRVVWBQVSL-UHFFFAOYSA-N strontium titanate Chemical compound [Sr+2].[O-][Ti]([O-])=O VEALVRVVWBQVSL-UHFFFAOYSA-N 0.000 description 1
- OGIDPMRJRNCKJF-UHFFFAOYSA-N titanium oxide Inorganic materials [Ti]=O OGIDPMRJRNCKJF-UHFFFAOYSA-N 0.000 description 1
- XJDNKRIXUMDJCW-UHFFFAOYSA-J titanium tetrachloride Chemical compound Cl[Ti](Cl)(Cl)Cl XJDNKRIXUMDJCW-UHFFFAOYSA-J 0.000 description 1
- 239000002341 toxic gas Substances 0.000 description 1
- 210000004881 tumor cell Anatomy 0.000 description 1
Landscapes
- Physical Or Chemical Processes And Apparatus (AREA)
- Catalysts (AREA)
- Oxygen, Ozone, And Oxides In General (AREA)
- Inorganic Compounds Of Heavy Metals (AREA)
Abstract
Description
【0001】[0001]
【産業上の利用分野】本発明は、TiO2 系複合超微粒
子及びその製造方法に関し、さらに詳しくはTiO2 か
らなる超微粒子表面にこれより小径の超微粒子が突出し
て担持されてなるTiO2 系複合超微粒子及びその製造
方法に関する。The present invention relates to relates to TiO 2 based composite ultrafine particles and a method of manufacturing the same, and more particularly TiO 2 based ultrafine particles of smaller diameter than that ultrafine particles surface made of TiO 2, which are carried projecting The present invention relates to composite ultrafine particles and a method for producing the same.
【0002】[0002]
【従来の技術】TiO2 は光触媒として非常に有効であ
ることが知られている。例えば、半導体(TiO2 )電
極と白金電極を水中に浸漬し、光を照射すると、半導体
電極中では、価電子帯にあった電子(e- )が伝導帯に
励起され、価電子帯には正孔(h+ )が生成する。その
結果、価電子帯に生じたh+ は半導体電極表面に移動
し、下記化1の反応式(1)に従って水と反応し、半導
体電極の表面から酸素が発生する。TiO 2 is known to be very effective as a photocatalyst. For example, when a semiconductor (TiO 2 ) electrode and a platinum electrode are immersed in water and irradiated with light, electrons (e − ) in the valence band in the semiconductor electrode are excited to the conduction band, and Holes (h + ) are generated. As a result, h + generated in the valence band moves to the surface of the semiconductor electrode, reacts with water according to the reaction formula (1) of the following chemical formula 1, and oxygen is generated from the surface of the semiconductor electrode.
【化1】 2H2 O + 4h+ → O2 ↑ + 4H+ … (1)Embedded image 2H 2 O + 4h + → O 2 ↑ + 4H + (1)
【0003】一方、伝導帯に生じた励起電子(e- )は
半導体電極内部より導線を通って白金電極に到達し、こ
こで下記化2の反応式(2)のようにプロトン(H+ )
を還元して水素を発生する。On the other hand, the excited electrons (e − ) generated in the conduction band reach the platinum electrode from the inside of the semiconductor electrode through the conducting wire, where the proton (H + ) is generated as shown in reaction formula (2) below.
Is reduced to generate hydrogen.
【化2】 2H+ + 2e- → H2 ↑ … (2) このような半導体電極による水の分解反応は、本多・藤
嶋効果と呼ばれている。2H + + 2e − → H 2 ↑ (2) The water decomposition reaction by such a semiconductor electrode is called the Honda-Fujishima effect.
【0004】本多・藤嶋らの研究を発端として、半導体
光電極についての研究が世界中で進められてきたが、半
導体電極を用いる代わりに、半導体粉末上にPtやRu
などの貴金属を付着させた光触媒によっても水の分解反
応が起こることが見い出されている。この原理は電極反
応と同様であり、ここでは、半導体粉末上に付着したP
tなどがカソードの役目をすると考えられている。半導
体としては、上記TiO2 の他、SrTiO3 (チタン
酸ストロンチウム)なども用いられる。このような光触
媒は、水の分解を行うよりもっと容易にアルコールや有
機物を分解することも知られている。また、TiO2 等
の半導体粉末あるいはこれにPt等を担持させた粉末
が、細菌類、放線菌、カビ類、藻類、酵母類等の各種微
生物や腫瘍細胞などに対して殺細胞作用を有することが
特公平4−29393号に開示されている。さらに、T
iO2 等の光触媒が脱臭効果を有することは特開平4−
307066号に、またこれらが口腔内の水分と触れて
いる状態で光照射を受けた時に発生するOHラジカルに
よって歯垢分解作用もしくは歯垢を生成させる病原菌た
るミュータンス菌に対する殺菌作用を示すことは特公平
3−20363号に開示されている。Since the research by Honda and Fujishima et al. Has been carried out around the world, research on semiconductor photoelectrodes has been carried out. Instead of using semiconductor electrodes, Pt or Ru is deposited on the semiconductor powder.
It has been found that the photocatalyst having a noble metal attached thereto also causes the decomposition reaction of water. This principle is similar to the electrode reaction, and here, the P attached on the semiconductor powder is used.
It is believed that t and the like act as a cathode. As the semiconductor, SrTiO 3 (strontium titanate) or the like may be used in addition to TiO 2 . It is also known that such photocatalysts decompose alcohols and organic substances more easily than water. In addition, semiconductor powder such as TiO 2 or powder in which Pt or the like is supported has a cell-killing effect on various microorganisms such as bacteria, actinomycetes, molds, algae, yeasts and tumor cells. Is disclosed in Japanese Examined Patent Publication No. 4-29393. Furthermore, T
the photocatalyst iO 2 or the like having a deodorizing effect Hei 4-
No. 307066, and these show bactericidal action against plaque-degrading action or mutans bacterium which is a pathogenic bacterium that produces plaque by OH radicals generated when they are exposed to light in a state where they are exposed to water in the oral cavity. It is disclosed in Japanese Examined Patent Publication No. 3-20363.
【0005】上記のようにTiO2 粒子の表面に金属を
付着した粉末の製造方法としては、例えば特開平2−6
333号には、四塩化チタンを気相酸化分解して得られ
たルチル型TiO2 粉末をまず塩化第一錫水溶液中に浸
漬し、次いで塩化パラジウム水溶液中に浸漬することに
よって、TiO2 粒子表面にパラジウムを付着させる方
法が開示されている。また、前記特公平3−20363
号には、塩化白金酸水溶液中に半導体粉末を懸濁させ、
窒素雰囲気下に光照射することにより白金を半導体上に
析出させる光電析法や、半導体粉末を白金黒と混練する
混練法が提案されている。As a method for producing a powder in which a metal is attached to the surface of TiO 2 particles as described above, for example, Japanese Patent Laid-Open No. 2-6
The No. 333, by titanium tetrachloride was immersed rutile TiO 2 powder obtained by vapor phase oxidative decomposition is first in stannous chloride aqueous solution and then immersed in a palladium chloride aqueous solution, TiO 2 particle surface A method of depositing palladium on is disclosed. In addition, the Japanese Patent Publication No. 3-20363
No. 1, semiconductor powder is suspended in a chloroplatinic acid aqueous solution,
A photodeposition method in which platinum is deposited on a semiconductor by irradiating light in a nitrogen atmosphere and a kneading method in which a semiconductor powder is kneaded with platinum black have been proposed.
【0006】[0006]
【発明が解決しようとする課題】前記したように、Ti
O2 は光触媒として非常に有効である。特に、TiO2
超微粒子の表面に金属やその酸化物等の超微粒子を担持
した複合超微粒子は、前記したような種々の触媒特性を
発現する高活性な光触媒として期待できる。従来、Ti
O2 粒子表面に金属等を付着させた粉末は、前記したよ
うに主として液相法により作製されている。しかしなが
ら、液体中で作製するために、粉末中に液体に含まれて
いる成分が不純物として残ってしまい、それによって触
媒としての活性が低くなってしまうという問題がある。
特に高活性の触媒を得るためには粉末の純度を上げるこ
とが必要となるが、液相法の場合には、その対応が困難
であるか、あるいは製造工程が複雑でコスト高なものと
なってしまう。As described above, Ti
O 2 is very effective as a photocatalyst. In particular, TiO 2
The composite ultrafine particles in which ultrafine particles such as a metal or an oxide thereof are supported on the surface of the ultrafine particles can be expected as a highly active photocatalyst exhibiting various catalytic properties as described above. Conventionally, Ti
The powder in which a metal or the like is attached to the surface of O 2 particles is mainly produced by the liquid phase method as described above. However, since it is produced in a liquid, there is a problem in that the components contained in the liquid in the powder remain as impurities, which reduces the activity as a catalyst.
Particularly in order to obtain a highly active catalyst, it is necessary to raise the purity of the powder, but in the case of the liquid phase method, it is difficult to cope with it, or the manufacturing process becomes complicated and costly. Will end up.
【0007】また、従来公知の液相法の場合、TiO2
粉末の化学的処理によってTiO2粒子表面に金属を付
着させるものである。TiO2 超微粒子の生成と同時
に、TiO2 超微粒子の表面に金属やその酸化物等の超
微粒子を担持したnmオーダーの複合超微粒子を気相法
により一段の工程で作製することは、本発明者らの知る
限りでは、従来知られていない。さらに、市販されてい
るアナターゼ型のTiO2 粉末はルチル型と比較して低
い温度で作製されるため不純物が多く、そのため、従来
公知の液相法においては、一般に出発材料としてアナタ
ーゼ型よりも不純物が少ないルチル型のTiO2粉末が
用いられている(前掲特開平2−6333号参照)。し
かしながら、反面、ルチル型のTiO2 粉末はアナター
ゼ型と比較して光触媒の活性が低いという難点がある。In the case of the conventionally known liquid phase method, TiO 2
The metal is attached to the surface of the TiO 2 particles by the chemical treatment of the powder. Simultaneously with the generation of TiO 2 ultrafine particles, can be produced by a vapor phase method composite ultrafine particles of nm order carrying ultrafine particles such as metal or its oxide on the surface of the TiO 2 ultrafine particles in one stage of the process, the present invention To the best of our knowledge, it has not been known so far. Furthermore, commercially available anatase-type TiO 2 powder has many impurities because it is produced at a lower temperature than rutile-type powder. Therefore, in the conventionally known liquid phase method, impurities as an starting material are generally used as impurities. A rutile type TiO 2 powder having a small amount is used (see Japanese Patent Application Laid-Open No. 2-6333). However, on the other hand, the rutile type TiO 2 powder has a drawback that the photocatalytic activity is lower than that of the anatase type.
【0008】従って、本発明の基本的な目的は、TiO
2 超微粒子の表面に金属やその酸化物等の超微粒子を担
持したnmオーダーの複合超微粒子を提供することにあ
る。さらに本発明の目的は、金属やその酸化物等の超微
粒子を担持するTiO2 の超微粒子がアナターゼ型及び
ルチル型両方のTiO2 超微粒子を含み、比較的広範囲
な波長域の光により前記したような種々の光触媒特性を
発現し得る高活性かつ高純度の複合超微粒子を提供する
ことにある。本発明の他の目的は、上記のような複合超
微粒子を気相法により一段の工程で比較的簡単に製造で
きる方法を提供することにある。Therefore, the basic object of the present invention is to obtain TiO 2.
(2) To provide nm-order composite ultrafine particles in which ultrafine particles such as a metal and its oxide are carried on the surface of the ultrafine particles. Further, the object of the present invention is that the TiO 2 ultrafine particles supporting ultrafine particles such as a metal and an oxide thereof include both anatase type and rutile type TiO 2 ultrafine particles, and are described above by light in a relatively wide wavelength range. It is to provide highly active and highly pure composite ultrafine particles capable of exhibiting various photocatalytic properties as described above. Another object of the present invention is to provide a method capable of producing the composite ultrafine particles as described above by a vapor phase method in a single step in a relatively simple manner.
【0009】[0009]
【課題を解決するための手段】前記目的を達成するため
に、本発明によれば、粒径が5〜300nmのTiO2
からなる超微粒子表面に、これより小径の粒径0.5〜
50nmの超微粒子が突出して担持されてなる複合超微
粒子であって、上記TiO2 超微粒子がアナターゼ型T
iO2 とルチル型TiO2 の超微粒子を含むことを特徴
とするTiO2系複合超微粒子が提供される。好適な態
様においては、前記担持される超微粒子はFe、Co、
Ni、Cu、Ru、Rh、Pd、Ag、Pt及びAuか
らなる群から選ばれた少なくとも1種の金属又は/及び
その化合物(セラミックスを含む)である。In order to achieve the above object, according to the present invention, TiO 2 having a particle size of 5 to 300 nm is used.
On the surface of ultrafine particles consisting of
A composite ultrafine particle in which ultrafine particles of 50 nm are projected and supported, wherein the TiO 2 ultrafine particles are anatase type T
Provided is a TiO 2 -based composite ultrafine particle, which contains ultrafine particles of iO 2 and rutile TiO 2 . In a preferred embodiment, the supported ultrafine particles are Fe, Co,
At least one metal selected from the group consisting of Ni, Cu, Ru, Rh, Pd, Ag, Pt, and Au, and / or a compound thereof (including ceramics).
【0010】さらに本発明によれば、前記のような複合
超微粒子を製造するための方法も提供され、その方法
は、一般式Ti・M(但し、MはFe、Co、Ni、C
u、Ru、Rh、Pd、Ag、Pt及びAuからなる群
から選ばれた少なくとも1種の元素である。)で示され
る組成からなる原材料を、酸素又は/及び窒素を含むガ
ス雰囲気中、不活性ガス雰囲気中、又は窒素ガス雰囲気
中で加熱溶解し、蒸発した原材料を上記雰囲気中の酸素
と反応させるか、又は超微粒子生成後に酸素と反応さ
せ、TiO2 からなる超微粒子表面にこれより小径の超
微粒子が突出して担持されてなる複合超微粒子を作製す
ることを特徴としている。好適な態様においては、上記
原材料としてTi50〜99原子%とM元素1〜50原
子%とからなる合金が用いられる。Further, according to the present invention, there is also provided a method for producing the composite ultrafine particles as described above, which method is represented by the general formula Ti.M (where M is Fe, Co, Ni, C).
It is at least one element selected from the group consisting of u, Ru, Rh, Pd, Ag, Pt, and Au. ) Is heated and melted in a gas atmosphere containing oxygen or / and nitrogen, in an inert gas atmosphere, or in a nitrogen gas atmosphere, and the evaporated raw material is reacted with oxygen in the atmosphere. Alternatively, after the formation of the ultrafine particles, it is reacted with oxygen to produce composite ultrafine particles in which ultrafine particles of TiO 2 are projected and carried on the surface of the ultrafine particles. In a preferred embodiment, an alloy composed of 50 to 99 atomic% of Ti and 1 to 50 atomic% of M element is used as the raw material.
【0011】[0011]
【発明の作用及び態様】本発明者らは、前記目的を達成
すべく鋭意研究の結果、アーク等により合金を溶融し超
微粒子を製造する際、その雰囲気として酸素又は/及び
窒素を含むガス雰囲気、不活性ガス雰囲気、又は窒素ガ
ス雰囲気を用いると共に、アーク等により溶解する母合
金として、一般式Ti・M(M=Fe、Co、Ni、C
u、Ru、Rh、Pd、Ag、Pt又はAu)で示され
る組成の合金を用いると、図1に示すように、TiO2
からなる超微粒子表面にこれより小径の金属(M)やそ
の酸化物(M−O)などの超微粒子が複数個接合した構
造のnmレベルの微細な複合超微粒子が作製されること
を見い出した。この場合、個々のTiO2 超微粒子はア
ナターゼ型TiO2 超微粒子又はルチル型TiO2 超微
粒子のいずれかからなるが、両方の型のTiO2 超微粒
子が生成する。すなわち、作製される複合超微粒子は、
全体的には、担体粒子(より小径の粒子を担持している
径の大きな粒子)がアナターゼ型のTiO2 からなる複
合超微粒子とルチル型のTiO2 からなる複合超微粒子
の混合物から構成されている。一方、個々のTiO2 超
微粒子により担持されるより小径の超微粒子は、金属
(M)やその酸化物のみであったり、あるいは金属とそ
の酸化物が混合して存在する。The present inventors have conducted extensive studies as a result of the achievement of the above-mentioned object. As a result, when an alloy is melted by an arc or the like to produce ultrafine particles, the atmosphere is a gas atmosphere containing oxygen and / or nitrogen. , An inert gas atmosphere or a nitrogen gas atmosphere is used, and as a master alloy that is melted by an arc or the like, a general formula Ti · M (M = Fe, Co, Ni, C
u, Ru, Rh, Pd, Ag, when an alloy having a composition represented by Pt or Au), as shown in FIG. 1, TiO 2
It was found that nano-scale fine composite ultrafine particles having a structure in which a plurality of ultrafine particles such as a metal (M) and its oxide (MO) having a smaller diameter are bonded to the surface of the ultrafine particles made of . In this case, the individual TiO 2 ultrafine particles consist of either anatase type TiO 2 ultrafine particles or rutile type TiO 2 ultrafine particles, but both types of TiO 2 ultrafine particles are produced. That is, the composite ultrafine particles produced are
Overall, the carrier particles (larger diameter particles carrying smaller particles) are composed of a mixture of composite ultrafine particles of anatase-type TiO 2 and composite ultrafine particles of rutile-type TiO 2. There is. On the other hand, the ultrafine particles having a smaller diameter carried by the individual TiO 2 ultrafine particles are only the metal (M) and its oxide, or are present as a mixture of the metal and its oxide.
【0012】雰囲気ガスとして酸素を含むガス(不活性
ガス又は窒素ガス)雰囲気を用いた場合、超微粒子生成
過程で前記した構造の複合超微粒子が作製される。一
方、雰囲気ガスが酸素を含まない場合、超微粒子生成過
程で生成した超微粒子は酸化物系とはなっていないの
で、その後酸素と反応させ、酸化物系に変換する必要が
ある。雰囲気ガスとして窒素ガスのみを用いた場合、T
iN粒子によってより小径のM金属粒子を複数個担持し
た構造の複合超微粒子が生成するので、その後、酸素雰
囲気(例えば大気)中で熱処理して酸化する。それによ
って、TiO2 超微粒子の表面にこれより小径の金属
(M)やその酸化物(M−O)が複数個接合した構造の
複合超微粒子が得られる。熱処理条件としては、200
〜600℃、好ましくは250〜400℃の温度で2分
〜4時間、好ましくは10分〜40分程度が適当であ
る。一方、雰囲気ガスとして不活性ガス(Ar,He,
Kr,Xe等)のみを用いた場合、TiとM金属の合金
もしくは化合物からなる超微粒子が生成するが、Ti粒
子は徐酸化処理過程で酸化されてTiO2 粒子に変化
し、またM金属粒子もその種類に応じて一部酸化され
る。ここで、徐酸化処理とは、蒸発室内で生成した超微
粒子をそのまま大気中に出すと燃焼してしまうため、酸
素を徐々にチャンバー内に供給して粒子表面に酸化膜を
形成して安定化する処理をいう。このような超微粒子の
生成過程については、Ti粒子が雰囲気ガスの流れによ
って運ばれている途中、M金属の蒸気がTi粒子表面で
凝縮して粒子状に接合し、酸化され易いTi粒子が徐酸
化処理の過程で酸化されてTiO2 粒子になるものと考
えられる。M金属粒子が酸化されるかどうかは、その金
属が酸化され易い金属であるかどうかに依存する。When a gas atmosphere containing oxygen (inert gas or nitrogen gas) is used as the atmosphere gas, composite ultrafine particles having the above-mentioned structure are produced in the process of producing ultrafine particles. On the other hand, when the atmospheric gas does not contain oxygen, the ultrafine particles produced in the process of producing ultrafine particles are not oxide-based, and therefore it is necessary to subsequently react with oxygen to convert them to oxide-based. When only nitrogen gas is used as the atmosphere gas, T
Since the iN particles generate composite ultrafine particles having a structure in which a plurality of M metal particles having a smaller diameter are supported, the composite ultrafine particles are thereafter heat-treated in an oxygen atmosphere (for example, air) to be oxidized. As a result, composite ultrafine particles having a structure in which a plurality of metals (M) and oxides thereof (MO) having a smaller diameter are bonded to the surface of the TiO 2 ultrafine particles can be obtained. The heat treatment condition is 200
It is suitable to be at a temperature of up to 600 ° C, preferably 250 to 400 ° C for 2 minutes to 4 hours, preferably 10 minutes to 40 minutes. On the other hand, an inert gas (Ar, He,
When only Kr, Xe, etc.) is used, ultrafine particles composed of an alloy or compound of Ti and M metal are produced, but the Ti particles are oxidized during the gradual oxidation process and converted into TiO 2 particles, and M metal particles Is also partially oxidized depending on its type. Here, the gradual oxidation treatment means that the ultrafine particles generated in the evaporation chamber will burn if they are directly exposed to the atmosphere, so oxygen is gradually supplied into the chamber to form an oxide film on the particle surface and stabilize it. This is the process to do. Regarding the generation process of such ultrafine particles, while Ti particles are being carried by the flow of atmospheric gas, vapor of M metal condenses on the surface of the Ti particles and joins them into particles, and the Ti particles that are easily oxidized are gradually removed. It is considered that the particles are oxidized into TiO 2 particles during the oxidation process. Whether or not the M metal particles are oxidized depends on whether or not the metal is a metal that is easily oxidized.
【0013】前記したように、アナターゼ型TiO2
は、光触媒の活性はルチル型TiO2と比較して高い
が、バンドギャップが3.2eVのため、ルチル型Ti
O2 と比較して350nm以下の短い波長の光のみしか
利用できないという難点がある。逆に、ルチル型TiO
2 は、光触媒の活性はアナターゼ型TiO2 と比較して
低いが、バンドギャップが3.0eVのため、アナター
ゼ型TiO2 と比較して400nmまでの若干長い波長
の光も利用できる。本発明により作製される複合超微粒
子の担体粒子は、TiO2 全体に対してアナターゼ型T
iO2 が50〜80重量%、ルチル型TiO2 が20〜
50重量%の割合を占めるため、単体のアナターゼ型T
iO2 やルチル型TiO2 に比べて、アナターゼ型Ti
O2 により触媒活性が高められ、またルチル型TiO2
の存在により有効に太陽光(波長360〜780nm)
を利用できる。As described above, the anatase type TiO 2
Has a higher photocatalytic activity than rutile-type TiO 2 , but has a band gap of 3.2 eV, the rutile-type Ti
There is a problem that only light with a short wavelength of 350 nm or less can be used as compared with O 2 . On the contrary, rutile TiO
2 , the activity of the photocatalyst is lower than that of the anatase type TiO 2 , but since the bandgap is 3.0 eV, light having a slightly longer wavelength up to 400 nm can be used as compared with the anatase type TiO 2 . Carrier particles of composite ultrafine particles produced by the present invention are anatase-type T with respect to TiO 2 total
50 to 80% by weight of iO 2 and 20 to 20 of rutile type TiO 2
Since it accounts for 50% by weight, it is a single anatase type T
Compared with iO 2 and rutile type TiO 2 , anatase type Ti
O 2 enhances catalytic activity, and rutile TiO 2
Due to the presence of sunlight (wavelength 360-780nm)
Is available.
【0014】一般に触媒反応は触媒表面で進行するた
め、触媒粒子を高純度かつ微細にすれば、単位質量当た
りの活性点が著しく増加し、高活性が期待できる。本発
明の方法によれば、後述する透過電子顕微鏡(TEM)
写真から明らかなように、粒径5〜300nmのTiO
2 からなる超微粒子表面にこれより小径の粒径0.5〜
50nmの金属やその酸化物などの超微粒子が突出して
担持されてなるnmオーダーの複合超微粒子が作製され
る。このように、本発明により得られる複合超微粒子
は、TiO2 超微粒子と金属やその酸化物等からなるよ
り微細な超微粒子がnmレベルで複合化していることに
より、高温での粒成長が起き難くなることが予想され、
特に高温使用下での耐久性が向上することが考えられ
る。また、従来の液相法により作製された酸化物粒子と
は異なり、粒子が極めて微細であり、かつ不純物を含ま
ず、純度が極めて高い。Since the catalytic reaction generally proceeds on the surface of the catalyst, if the catalyst particles are made highly pure and fine, the number of active sites per unit mass is remarkably increased, and high activity can be expected. According to the method of the present invention, a transmission electron microscope (TEM) described below is used.
As is clear from the photograph, TiO with a particle size of 5 to 300 nm
The small diameter of the particle size of 0.5 to than this to ultra-fine particles surface consisting of two
Nano-scale composite ultra-fine particles in which ultra-fine particles of 50 nm of metal or oxide thereof are projected and carried are produced. As described above, in the composite ultrafine particles obtained by the present invention, since TiO 2 ultrafine particles and finer ultrafine particles made of metal or oxide thereof are compounded at the nm level, grain growth at high temperature occurs. Expected to be difficult,
It is considered that the durability is improved especially under high temperature use. Further, unlike the oxide particles produced by the conventional liquid phase method, the particles are extremely fine, contain no impurities, and have extremely high purity.
【0015】従って、本発明の方法により得られる複合
超微粒子は、前記したような水の完全分解反応のための
光触媒として有効に用い得るだけでなく、非常に強力な
酸化−還元性触媒のため、二酸化炭素の分解触媒、アル
コールの脱水、脱水素化反応触媒、フロンの分解触媒、
有毒ガスの分解触媒等として用いることができる。この
他にも、上記のような性質を利用して、本発明の複合超
微粒子を有効成分として含有する抗菌、殺菌、滅菌、タ
バコの煙の分解などの作用を持った膜や粉末として、ガ
ラス上や建築部材上にコーティングし、これらを建物の
窓ガラスや建材として用い、室内の殺菌、消臭、防黴に
活用することができる。さらに、複合超微粒子の生成に
用いる母合金の元素(M)の種類や組成比を変化させる
ことにより、生成粉末の色を赤、黒、青等に自由に変化
させることができるため、抗菌特性を持った塗料として
利用することも可能である。Therefore, the composite ultrafine particles obtained by the method of the present invention can be effectively used not only as a photocatalyst for the complete decomposition reaction of water as described above but also because it is a very strong oxidation-reduction catalyst. , Carbon dioxide decomposition catalyst, alcohol dehydration, dehydrogenation reaction catalyst, CFC decomposition catalyst,
It can be used as a catalyst for decomposing toxic gases. In addition to the above, utilizing the above properties, antibacterial containing the composite ultrafine particles of the present invention as an active ingredient, sterilization, sterilization, as a film or powder having the action of decomposing tobacco smoke, glass, It can be used for indoor sterilization, deodorization, and mildew proofing by coating the top and building materials and using them as building window glass and building materials. Furthermore, the color of the produced powder can be freely changed to red, black, blue, etc. by changing the type and composition ratio of the element (M) of the mother alloy used for the production of the composite ultrafine particles, so that the antibacterial property It is also possible to use it as a paint with.
【0016】使用する原材料の組成としては、チタン5
0〜99原子%、M元素1〜50原子%の範囲内が好ま
しく、この範囲内の原材料を用いることにより、前記し
たような構造を有する触媒活性の高い複合超微粒子を作
製できる。原材料中のチタンの量が50原子%未満の場
合、作製される超微粒子に含有されるM金属やその酸化
物の割合が多くなり過ぎ、超微粒子が図1に示すような
触媒材料としての理想形態の複合超微粒子になり難くな
る。また、M金属やその酸化物単独の超微粒子が発生し
易くなり、またその粒成長が起こり易くなるので好まし
くない。逆に、チタンの量が99原子%を超えた場合に
も、図1に示すような構造の複合超微粒子になり難く、
全体としての触媒活性が低下する傾向にあるので好まし
くない。The composition of the raw materials used is titanium 5
It is preferably in the range of 0 to 99 atomic% and M element in the range of 1 to 50 atomic%. By using the raw materials in this range, composite ultrafine particles having the above-described structure and high catalytic activity can be produced. If the amount of titanium in the raw material is less than 50 atomic%, the proportion of M metal and its oxide contained in the ultrafine particles produced becomes too large, and the ultrafine particles are ideal as a catalyst material as shown in FIG. It becomes difficult to form composite ultrafine particles. Further, ultrafine particles of M metal or its oxide alone are likely to be generated, and grain growth thereof is likely to occur, which is not preferable. On the contrary, even when the amount of titanium exceeds 99 atomic%, it is difficult to form the composite ultrafine particles having the structure shown in FIG.
It is not preferable because the catalytic activity as a whole tends to decrease.
【0017】本発明の複合超微粒子を作製する雰囲気と
しては、前記したように酸素又は/及び窒素を含むガス
雰囲気を用いることができるが、好ましくは酸素ガスを
含む不活性ガス(Ar,He,Kr,Xe,N2 等)を
用いることが望ましい。この場合の雰囲気ガスの組成と
しては、Ar、He、N2 等の不活性ガス50〜99
%、酸素ガス1〜50%の範囲、特に不活性ガス50〜
95%、酸素ガス5〜50%の範囲が好ましい。雰囲気
中の酸素ガスの割合が1%未満の場合、酸素プラズマの
効果が殆どなくなり、酸化物が生成し難く、図1に示す
ような理想的な形態の複合超微粒子が作製され難くな
る。一方、酸素ガスの割合が50%を超えると、酸素プ
ラズマの効果が強くなり、原料の母合金の表面が酸化膜
で覆われてしまい、アークが不安定になったり、最悪の
場合発生しなくなり、超微粒子が作製されなくなる恐れ
がある。原料の母合金の表面が酸化膜で覆われ難いよう
にし、また図1に示すような理想的な形態の複合超微粒
子が作製され易いようにするためには、混合ガス中の酸
素ガスの割合は5〜20%の範囲がより好ましい。な
お、酸素ガスと窒素ガスの混合ガスの場合、乾燥空気を
利用することもでき、それによって複合超微粒子を安価
に製造することができる。雰囲気ガスの圧力は10To
rr以上、好ましくは50Torr以上、1500To
rr以下の範囲が適当である。10Torr未満ではア
ークプラズマが不安定となり、超微粒子が発生し難くな
る。一方、1500Torrを超えると、発生する超微
粒子の生成量は殆ど変化しなくなる。As the atmosphere for producing the composite ultrafine particles of the present invention, a gas atmosphere containing oxygen or / and nitrogen can be used as described above, but an inert gas containing oxygen gas (Ar, He, Kr, Xe, N 2 etc.) is preferably used. In this case, the composition of the atmosphere gas is such that an inert gas such as Ar, He or N 2 is 50 to 99.
%, Oxygen gas in the range of 1 to 50%, especially inert gas 50 to
A range of 95% and oxygen gas of 5 to 50% is preferable. When the proportion of oxygen gas in the atmosphere is less than 1%, the effect of oxygen plasma is almost eliminated, oxides are less likely to be formed, and it becomes difficult to produce composite ultrafine particles having an ideal form as shown in FIG. On the other hand, when the proportion of oxygen gas exceeds 50%, the effect of oxygen plasma becomes strong, the surface of the raw material mother alloy is covered with an oxide film, and the arc becomes unstable, or in the worst case it does not occur. However, ultrafine particles may not be produced. In order to make it difficult for the surface of the raw material mother alloy to be covered with an oxide film and to facilitate the production of ideal composite ultrafine particles as shown in FIG. 1, the proportion of oxygen gas in the mixed gas Is more preferably in the range of 5 to 20%. In the case of a mixed gas of oxygen gas and nitrogen gas, dry air can also be used, whereby composite ultrafine particles can be manufactured at low cost. Atmospheric gas pressure is 10To
rr or more, preferably 50 Torr or more, 1500 To
A range of rr or less is suitable. If it is less than 10 Torr, the arc plasma becomes unstable and it becomes difficult to generate ultrafine particles. On the other hand, when it exceeds 1500 Torr, the amount of ultrafine particles generated hardly changes.
【0018】尚、母合金は酸素ガスを含む不活性ガス雰
囲気で溶解する前に、予め不活性ガス雰囲気中で溶製し
ておくことが好ましいが、この母合金は酸素ガスを含む
不活性ガス雰囲気で溶解する前に同じ超微粒子作製装置
内で不活性ガス雰囲気中もしくは真空中で作製してもよ
く、あるいは別のアーク溶解装置等の高温溶解装置を用
いて作製しても良い。また、本発明における加熱溶解法
としては、アーク溶解法の他、高周波加熱溶解法、プラ
ズマジェット加熱法、高周波誘導加熱法(高周波プラズ
マ加熱)、電子ビーム加熱法、レーザービーム加熱法な
ども用いることが可能である。The master alloy is preferably melted in an inert gas atmosphere in advance before being melted in an inert gas atmosphere containing oxygen gas. This master alloy is inert gas containing oxygen gas. Before melting in an atmosphere, it may be manufactured in the same ultrafine particle manufacturing apparatus in an inert gas atmosphere or in a vacuum, or may be manufactured using another high temperature melting apparatus such as an arc melting apparatus. Further, as the heating melting method in the present invention, in addition to the arc melting method, a high frequency heating melting method, a plasma jet heating method, a high frequency induction heating method (high frequency plasma heating), an electron beam heating method, a laser beam heating method, etc. may be used. Is possible.
【0019】[0019]
【実施例】以下、実施例を示して本発明について具体的
に説明するが、本発明が下記実施例に限定されるもので
ないことはもとよりである。EXAMPLES The present invention will be specifically described below with reference to examples, but it goes without saying that the present invention is not limited to the following examples.
【0020】図2は、本発明に従ってアーク溶解により
複合超微粒子を作製するのに好適な装置の一例を示し、
後述する実施例において使用した装置の概略構成図であ
る。この装置1は、溶解室2とグローブボックス3とか
らなる。溶解室2内には、原料(母合金)Aを配置する
ハース4がモータ12により回転自在に配設されてい
る。また、溶解室2内のハース4上部には、ハース4に
配置された母合金Aに接近自在にアーク電極5が配設さ
れている。溶解室2とグローブボックス3は収集管6に
よって連通されており、該収集管6のグローブボックス
3内に位置する収集管後端7にはフィルター8が着脱自
在に取り付けられている。符号9はガス混合器であり、
所定濃度の酸素ガスを含む不活性ガスを溶解室2中へ供
給する。符号10はターボ分子ポンプ、11はメカニカ
ルブースターポンプとロータリーポンプであり、これら
によって溶解室2とグローブボックス3との間の差圧が
制御される。FIG. 2 shows an example of an apparatus suitable for producing composite ultrafine particles by arc melting according to the present invention,
It is a schematic block diagram of the apparatus used in the Example mentioned later. This apparatus 1 comprises a melting chamber 2 and a glove box 3. In the melting chamber 2, a hearth 4 for arranging the raw material (mother alloy) A is rotatably arranged by a motor 12. An arc electrode 5 is arranged above the hearth 4 in the melting chamber 2 so as to be accessible to the mother alloy A arranged in the hearth 4. The melting chamber 2 and the glove box 3 are communicated with each other by a collecting pipe 6, and a filter 8 is detachably attached to a rear end 7 of the collecting pipe 6 located inside the glove box 3. Reference numeral 9 is a gas mixer,
An inert gas containing a predetermined concentration of oxygen gas is supplied into the melting chamber 2. Reference numeral 10 is a turbo molecular pump, and 11 is a mechanical booster pump and a rotary pump, which control the differential pressure between the melting chamber 2 and the glove box 3.
【0021】次に、操作手順について説明する。まず、
溶解室2内のハース4に母合金Aを配置した後、装置内
の真空引きを行う。装置内の真空度が所定の圧力(1×
10-3Torr)以下になった後に、所定濃度の酸素ガ
スを含む不活性ガスを所定の流量(1〜200 l/m
in.)で溶解室2内へ供給し、溶解室2内のガス圧を
所定の圧力に設定する。この際、雰囲気ガスとして大気
を用いる場合以外は、上記のように装置内を予め真空引
きしておいた方が好ましい。その後、通常のアーク溶解
と同様、母合金Aとアーク電極5との間でアーク放電を
起こしてアークプラズマCを発生させることにより、母
合金Aが高温になり、蒸発し、超微粒子Bが発生する。
この母合金Aから発生した超微粒子Bは、雰囲気中の酸
素と反応し、溶解室2とグローブボックス3との間の差
圧によって生ずるガスの流れに乗って収集管6に吸引さ
れ、その後端に設置されたフィルター8により捕集され
る。Next, the operation procedure will be described. First,
After the mother alloy A is placed on the hearth 4 in the melting chamber 2, the inside of the apparatus is evacuated. The degree of vacuum in the device depends on the specified pressure (1 x
After becoming 10 −3 Torr or less, an inert gas containing a predetermined concentration of oxygen gas is supplied at a predetermined flow rate (1 to 200 l / m
in. ), And the gas pressure in the melting chamber 2 is set to a predetermined pressure. At this time, it is preferable to evacuate the inside of the apparatus in advance as described above, except when the atmosphere is used as the atmospheric gas. After that, as in the case of normal arc melting, an arc discharge is generated between the mother alloy A and the arc electrode 5 to generate an arc plasma C, so that the mother alloy A is heated to a high temperature and evaporated to generate ultrafine particles B. To do.
The ultrafine particles B generated from the mother alloy A react with oxygen in the atmosphere and are sucked by the collecting pipe 6 along with the gas flow generated by the pressure difference between the melting chamber 2 and the glove box 3, and the rear end It is collected by the filter 8 installed at.
【0022】実施例1 各々99.9mass%以上の純度を持つチタンとパラ
ジウムを原料とし、Ar雰囲気中でアーク溶解を行い、
89.6at%Ti−10.4at%Pdの組成を有す
る合金のボタン状インゴットを作製した。ここで、8
9.6at%Ti−10.4at%Pdの母合金組成と
した理由は、超微粒子作製の際にTiとPdがほぼ同程
度に発生すると仮定して、生成超微粒子のTiO2 に対
するPdの体積分率が5%になるように計算から求めた
ことによる。このボタン状インゴットを用い、図2に示
すような装置により、10%の酸素ガスを含むArガス
の雰囲気(ガス圧200Torr)中においてアーク溶
解を行い、複合超微粒子を製造した。生成超微粒子の相
の同定はX線回折法を用い、また超微粒子の構造の観察
は透過電子顕微鏡(TEM)により行った。Example 1 Using titanium and palladium as raw materials each having a purity of 99.9 mass% or more, arc melting was performed in an Ar atmosphere,
An alloy button ingot having a composition of 89.6 at% Ti-10.4 at% Pd was prepared. Where 8
The reason why the mother alloy composition of 9.6 at% Ti-10.4 at% Pd is set is that it is assumed that Ti and Pd are generated at approximately the same level during the production of ultrafine particles, and the volume of Pd with respect to TiO 2 of the produced ultrafine particles is increased. This is because it was calculated so that the fraction would be 5%. Using this button-shaped ingot, arc melting was carried out in an Ar gas atmosphere (gas pressure of 200 Torr) containing 10% oxygen gas by an apparatus as shown in FIG. 2 to produce composite ultrafine particles. The phase of the generated ultrafine particles was identified by an X-ray diffraction method, and the structure of the ultrafine particles was observed by a transmission electron microscope (TEM).
【0023】図3に、上記のようにして作製した超微粒
子のX線回折図を示す。図3から明らかなように、Ti
O2 とPdが生成しており、またTiO2 はアナターゼ
型とルチル型の両方が生成していた。図4は、作製した
超微粒子のTEM(透過電子顕微鏡)写真を示す。図4
から明らかなように、約10〜300nmの略球状の超
微粒子に約1〜50nmの超微粒子が一体的に接合さ
れ、担持された複合形態を有する複合超微粒子が作製さ
れた。これらの複合超微粒子は、エネルギー分散型検出
法(SEM EDX)により調べた結果、微細な超微粒
子を担持する担体超微粒子からはTiの強いピークのみ
が検出され、一方、担体超微粒子に担持された超微粒子
からはTi及びPdのピークが検出された。上記X線回
折、TEM、及びEDXの結果より、作製された複合超
微粒子は、TiO2 超微粒子とそれに担持されたより微
細なPd超微粒子がnmレベルで複合した酸化物−金属
複合超微粒子になっているものと考えられる。FIG. 3 shows an X-ray diffraction pattern of the ultrafine particles produced as described above. As is clear from FIG.
O 2 and Pd were produced, and both anatase type and rutile type of TiO 2 were produced. FIG. 4 shows a TEM (transmission electron microscope) photograph of the produced ultrafine particles. FIG.
As is clear from the above, composite ultrafine particles having a composite morphology in which ultrafine particles of approximately 1 to 50 nm were integrally bonded to approximately spherical ultrafine particles of approximately 10 to 300 nm were produced. As a result of investigating these composite ultrafine particles by an energy dispersive detection method (SEM EDX), only a strong peak of Ti was detected from the carrier ultrafine particles carrying the fine ultrafine particles, while the carrier ultrafine particles were supported by the carrier ultrafine particles. Peaks of Ti and Pd were detected in the ultrafine particles. From the results of the above X-ray diffraction, TEM, and EDX, the produced composite ultrafine particles were oxide-metal composite ultrafine particles in which TiO 2 ultrafine particles and the finer Pd ultrafine particles carried thereon were combined at the nm level. It is considered that
【0024】複合超微粒子の触媒特性:前記のようにし
て作製した複合超微粒子について、メタノールの水蒸気
改質触媒としての調査を行った。また、比較として、市
販のCuO−ZnO−Al2 O3 触媒についても調査を
行った。触媒性能評価は超微粒子0.1gを充填した常
圧固定床流通式反応装置を用いて行った。各触媒を用い
た水蒸気改質反応について、種々の温度における水素発
生量を図5に示す。図5から明らかなように、本発明の
複合超微粒子は、市販触媒と同等程度の高い触媒活性を
示した。Catalytic properties of composite ultrafine particles: The composite ultrafine particles produced as described above were investigated as a steam reforming catalyst for methanol. Further, as a comparison, it was also investigated for commercial CuO-ZnO-Al 2 O 3 catalyst. The catalyst performance was evaluated using an atmospheric pressure fixed bed flow type reaction apparatus filled with 0.1 g of ultrafine particles. FIG. 5 shows the amount of hydrogen generated at various temperatures in the steam reforming reaction using each catalyst. As is clear from FIG. 5, the composite ultrafine particles of the present invention exhibited a catalytic activity as high as that of a commercially available catalyst.
【0025】複合超微粒子の抗菌作用:前記のようにし
て作製したTiO2 系複合超微粒子をお菓子の上に振り
撒いてその抗菌作用を調査した。また、対照としてTi
O2 系複合超微粒子を振り撒いていないお菓子を用い
た。抗菌作用は、黴の発生している面積の範囲(%)に
より評価した。その結果を表1に示す。Antibacterial action of composite ultrafine particles: The antibacterial action of TiO 2 -based composite ultrafine particles prepared as described above was sprinkled on a candy to investigate its antibacterial action. Also, as a control, Ti
A sweet that was not sprinkled with O 2 -based composite ultrafine particles was used. The antibacterial action was evaluated by the range (%) of the area where mold was generated. Table 1 shows the results.
【表1】 上記表1に示す結果から明らかなように、本発明のTi
O2 系複合超微粒子は長期間にわたって優れた防黴作用
を示した。[Table 1] As is clear from the results shown in Table 1 above, Ti of the present invention
The O 2 -based composite ultrafine particles exhibited an excellent antifungal action for a long period of time.
【0026】実施例2 実施例1と同様にして、89.6at%Ti−10.4
at%Pdの組成を有する合金のボタン状インゴットを
作製した。このボタン状インゴットを用い、図2に示す
ような装置により、10%の酸素ガスを含むHeガスの
雰囲気(ガス圧50Torr)中においてアーク溶解を
行い、複合超微粒子を製造した。Example 2 In the same manner as in Example 1, 89.6 at% Ti-10.4.
An alloy button ingot having a composition of at% Pd was prepared. Using this button-shaped ingot, arc melting was carried out in an atmosphere of He gas containing 10% oxygen gas (gas pressure 50 Torr) using a device as shown in FIG. 2 to produce composite ultrafine particles.
【0027】図6に、上記のようにして作製した超微粒
子のX線回折図を示す。図6から明らかなように、Ti
O2 とPdが生成しており、またTiO2 はアナターゼ
型とルチル型の両方が生成していた。図7は、作製した
超微粒子のTEM(透過電子顕微鏡)写真を示す。図7
から明らかなように、約5〜100nmの略球状の超微
粒子に約0.5〜30nmの超微粒子が一体的に接合さ
れ、担持された複合形態を有する複合超微粒子が作製さ
れた。上記X線回折及びTEM観察の結果、並びにエネ
ルギー分散型検出法(SEMEDX)により調べた結果
より、作製された複合超微粒子は、TiO2 超微粒子と
それに担持されたより微細なPd超微粒子がnmレベル
で複合した酸化物−金属複合超微粒子になっているもの
と考えられる。FIG. 6 shows an X-ray diffraction pattern of the ultrafine particles produced as described above. As is clear from FIG.
O 2 and Pd were produced, and both anatase type and rutile type of TiO 2 were produced. FIG. 7 shows a TEM (transmission electron microscope) photograph of the produced ultrafine particles. Figure 7
As is apparent from the above, composite ultrafine particles having a composite morphology supported by integrally bonding ultrafine particles of approximately 0.5 to 30 nm to approximately spherical ultrafine particles of approximately 5 to 100 nm were produced. From the results of the above X-ray diffraction and TEM observation, and the results of examination by the energy dispersive detection method (SEMEDX), the produced composite ultrafine particles were TiO 2 ultrafine particles and finer Pd ultrafine particles carried thereon in the nm level. It is considered that the oxide-metal composite ultrafine particles are composited in (1).
【0028】[0028]
【発明の効果】以上のように、本発明のの方法により得
られる複合超微粒子は、TiO2 超微粒子表面に、これ
より小径のM元素(但し、MはFe、Co、Ni、C
u、Ru、Rh、Pd、Ag、Pt及びAuからなる群
から選ばれた少なくとも1種の金属である。)からなる
金属やその酸化物等の超微粒子が突出して担持された構
造のnmオーダーの複合超微粒子であり、比較的高温域
においても安定に複合状態が保持される。また、本発明
の複合超微粒子は、従来の液相法により作製された酸化
物粒子とは異なり、粒子が極めて微細であり、かつ不純
物を含まず、純度が極めて高い。従って、本発明に係る
複合超微粒子は、前記したような水の完全分解反応のた
めの光触媒として有効に用い得るだけでなく、非常に強
力な酸化−還元性触媒のため、二酸化炭素の分解触媒、
アルコールの脱水、脱水素化反応触媒、フロンの分解触
媒、有毒ガスの分解触媒等各種触媒や抗菌剤、防黴剤な
どとして用いることができる。また、本発明の複合超微
粒子の担体粒子は、アナターゼ型TiO2 超微粒子とル
チル型TiO2 超微粒子を含むものであるため、単体の
アナターゼ型TiO2やルチル型TiO2 に比べて、ア
ナターゼ型TiO2 により触媒活性が高められ、またル
チル型TiO2 の存在により有効に太陽光(波長360
〜780nm)を利用できる。また、本発明によれば、
種々の触媒活性を示す上記のような複合超微粒子を、気
相法により安価にしかも比較的簡単な方法により作製で
きる。INDUSTRIAL APPLICABILITY As described above, the composite ultrafine particles obtained by the method of the present invention have M elements of smaller diameter (where M is Fe, Co, Ni, C) on the surface of the TiO 2 ultrafine particles.
It is at least one metal selected from the group consisting of u, Ru, Rh, Pd, Ag, Pt and Au. Is a nanometer-order composite ultrafine particle having a structure in which ultrafine particles such as a metal and an oxide thereof are projected and supported, and the composite state is stably maintained even in a relatively high temperature range. Further, unlike the oxide particles produced by the conventional liquid phase method, the composite ultrafine particles of the present invention have extremely fine particles, contain no impurities, and have extremely high purity. Therefore, the composite ultrafine particles according to the present invention can be effectively used as a photocatalyst for the complete decomposition reaction of water as described above, and also because it is a very strong oxidation-reduction catalyst, it is a decomposition catalyst of carbon dioxide. ,
It can be used as various catalysts such as alcohol dehydration and dehydrogenation reaction catalysts, freon decomposition catalysts, poisonous gas decomposition catalysts, antibacterial agents and antifungal agents. Further, carrier particles of composite ultrafine particles of the present invention, since those containing anatase TiO 2 ultrafine particles and rutile-type TiO 2 ultrafine particles, compared to a single anatase TiO 2 and rutile TiO 2, anatase TiO 2 The catalytic activity is enhanced by the presence of rutile TiO 2 and the sunlight (wavelength 360
˜780 nm) is available. Further, according to the present invention,
The above-mentioned composite ultrafine particles exhibiting various catalytic activities can be produced by the gas phase method at a low cost and by a relatively simple method.
【図1】本発明の複合超微粒子の構造を概略的に示す模
式図である。FIG. 1 is a schematic view schematically showing the structure of composite ultrafine particles of the present invention.
【図2】本発明に従ってアーク溶解により複合超微粒子
を作製する装置の一例の概略構成図である。FIG. 2 is a schematic configuration diagram of an example of an apparatus for producing composite ultrafine particles by arc melting according to the present invention.
【図3】実施例1において、89.6at%Ti−1
0.4at%Pdの母合金を用い、10%の酸素ガスを
含むArガス雰囲気(ガス圧200Torr)中におい
て作製した複合超微粒子のX線回折図である。FIG. 3 is the same as Example 1 except that 89.6 at% Ti-1.
FIG. 4 is an X-ray diffraction diagram of composite ultrafine particles produced in an Ar gas atmosphere (gas pressure of 200 Torr) containing 10% oxygen gas using a 0.4 at% Pd mother alloy.
【図4】実施例1で作製した複合超微粒子の透過電子顕
微鏡写真である。FIG. 4 is a transmission electron micrograph of the composite ultrafine particles produced in Example 1.
【図5】実施例1で作製した複合超微粒子を触媒として
用いたメタノールの水蒸気改質反応において、種々の温
度における水素発生量を示すグラフである。FIG. 5 is a graph showing the amount of hydrogen generated at various temperatures in a steam reforming reaction of methanol using the composite ultrafine particles produced in Example 1 as a catalyst.
【図6】実施例2において、89.6at%Ti−1
0.4at%Pdの母合金を用い、10%の酸素ガスを
含むHeガス雰囲気(ガス圧50Torr)中において
作製した複合超微粒子のX線回折図である。FIG. 6 is the same as Example 2 except that 89.6 at% Ti-1 is used.
FIG. 3 is an X-ray diffraction diagram of composite ultrafine particles produced in a He gas atmosphere (gas pressure of 50 Torr) containing 10% oxygen gas using a master alloy of 0.4 at% Pd.
【図7】実施例2で作製した複合超微粒子の透過電子顕
微鏡写真である。FIG. 7 is a transmission electron micrograph of the composite ultrafine particles produced in Example 2.
1 超微粒子作製装置 2 溶解室 3 グローブボックス 5 アーク電極 6 収集管 8 フィルター 9 ガス混合器 10 ターボ分子ポンプ 11 メカニカルブースターポンプ、ロータリーポンプ A 母合金 B 超微粒子 C アークプラズマ 1 Ultrafine Particle Production Device 2 Melting Chamber 3 Glove Box 5 Arc Electrode 6 Collection Tube 8 Filter 9 Gas Mixer 10 Turbo Molecular Pump 11 Mechanical Booster Pump, Rotary Pump A Mother Alloy B Ultrafine Particle C Arc Plasma
───────────────────────────────────────────────────── フロントページの続き (51)Int.Cl.6 識別記号 庁内整理番号 FI 技術表示箇所 B01J 23/89 B01J 23/89 M 35/02 35/02 J C01B 13/14 C01B 13/14 Z ─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. 6 Identification code Internal reference number FI Technical display location B01J 23/89 B01J 23/89 M 35/02 35/02 J C01B 13/14 C01B 13/14 Z
Claims (5)
る超微粒子表面に、これより小径の粒径0.5〜50n
mの超微粒子が突出して担持されてなる複合超微粒子で
あって、上記TiO2 超微粒子がアナターゼ型TiO2
とルチル型TiO2 の超微粒子を含むことを特徴とする
TiO2 系複合超微粒子。1. An ultrafine particle surface made of TiO 2 having a particle diameter of 5 to 300 nm, and a particle diameter of 0.5 to 50 n having a smaller diameter than that.
m is a composite ultrafine particle in which ultrafine particles of m are projected and carried, wherein the TiO 2 ultrafine particles are anatase type TiO 2
And TiO 2 composite ultrafine particles comprising the ultrafine particles of rutile TiO 2.
i、Cu、Ru、Rh、Pd、Ag、Pt及びAuから
なる群から選ばれた少なくとも1種の金属又は/及びそ
の化合物(セラミックスを含む)である請求項1に記載
のTiO2 系複合超微粒子。2. The supported ultrafine particles are Fe, Co, N.
The TiO 2 -based composite superstructure according to claim 1, which is at least one metal selected from the group consisting of i, Cu, Ru, Rh, Pd, Ag, Pt and Au and / or a compound thereof (including ceramics). Fine particles.
ゼ型TiO2 超微粒子50〜80重量%とルチル型Ti
O2 超微粒子20〜50重量%からなる請求項1又は2
に記載のTiO2 系複合超微粒子。Wherein ultrafine particles composed of TiO 2 is anatase TiO 2 ultrafine particles 50 to 80% by weight and a rutile type Ti
The ultrafine particles of O 2 comprising 20 to 50% by weight.
TiO 2 -based composite ultrafine particles described in 1.
o、Ni、Cu、Ru、Rh、Pd、Ag、Pt及びA
uからなる群から選ばれた少なくとも1種の元素であ
る。)で示される組成からなる原材料を、酸素又は/及
び窒素を含むガス雰囲気中、不活性ガス雰囲気中、又は
窒素ガス雰囲気中で加熱溶解し、蒸発した原材料を上記
雰囲気中の酸素と反応させるか、又は超微粒子生成後に
酸素と反応させ、TiO2 からなる超微粒子表面にこれ
より小径の超微粒子が突出して担持されてなる複合超微
粒子を作製することを特徴とするTiO2 系複合超微粒
子の製造方法。4. The general formula Ti.M (where M is Fe, C
o, Ni, Cu, Ru, Rh, Pd, Ag, Pt and A
It is at least one element selected from the group consisting of u. ) Is heated and melted in a gas atmosphere containing oxygen or / and nitrogen, in an inert gas atmosphere, or in a nitrogen gas atmosphere, and the evaporated raw material is reacted with oxygen in the atmosphere. , or super after particles produced is reacted with oxygen, of smaller diameter than that ultrafine particles surface made of TiO 2 ultrafine particles, which are carried projecting composite ultrafine particles features that TiO 2 based composite ultrafine particles to produce Production method.
元素1〜50原子%とからなる合金を用いる請求項4に
記載の方法。5. Ti = 50 to 99 atomic% and M as raw materials
The method according to claim 4, wherein an alloy consisting of 1 to 50 atomic% of elements is used.
Priority Applications (1)
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JP7109172A JPH08283022A (en) | 1995-04-11 | 1995-04-11 | Titanium dioxide based composite superfine particle and its production |
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Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP7109172A JPH08283022A (en) | 1995-04-11 | 1995-04-11 | Titanium dioxide based composite superfine particle and its production |
Publications (1)
Publication Number | Publication Date |
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JPH08283022A true JPH08283022A (en) | 1996-10-29 |
Family
ID=14503490
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- 1995-04-11 JP JP7109172A patent/JPH08283022A/en active Pending
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Publication number | Priority date | Publication date | Assignee | Title |
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JPH0966237A (en) * | 1995-08-30 | 1997-03-11 | Agency Of Ind Science & Technol | Photocatalyst particles and synthesis thereof |
JPH0975746A (en) * | 1995-09-08 | 1997-03-25 | Okaya Electric Ind Co Ltd | Magnetic photocatalyst material, water treatment the same and water treating device using |
WO1998011984A1 (en) * | 1996-09-20 | 1998-03-26 | Daiken Chemical Co., Ltd. | Ultrafine metal particle carrying photocatalyst, highly function material loaded with the photocatalyst, and method of manufacturing them |
CN1078181C (en) * | 1997-11-14 | 2002-01-23 | 中国科学院化工冶金研究所 | Process for producing nanometre-grade titanic-schorl type titanium dioxide |
EP1393803A1 (en) * | 2001-03-29 | 2004-03-03 | Ecodevice Corporation | Light-responsive material and method of manufacturing the same |
JP2003251195A (en) * | 2002-03-01 | 2003-09-09 | Tayca Corp | Titanium oxide photocatalyst having excellent nitrogen oxide removing capacity |
WO2004026471A1 (en) * | 2002-09-20 | 2004-04-01 | Andes Electric Co.,Ltd. | Photocatalyst material and process for producing the same |
CN1323752C (en) * | 2005-04-30 | 2007-07-04 | 中国地质大学(武汉) | Manufacture of Ag+-Fe+ dosed TiO2 weakly exciting catalytic luminating film |
JP2009233590A (en) * | 2008-03-27 | 2009-10-15 | National Institute Of Advanced Industrial & Technology | Toxic substance treatment method and device for treatment |
JP5548991B2 (en) * | 2009-02-02 | 2014-07-16 | 独立行政法人物質・材料研究機構 | TiO2 nanoparticles |
WO2010087445A1 (en) * | 2009-02-02 | 2010-08-05 | パイオニア株式会社 | TiO2 NANOPARTICLES |
JP2009148764A (en) * | 2009-04-06 | 2009-07-09 | Japan Fine Ceramics Center | Manufacturing method for photocatalyst composite material |
WO2012105631A1 (en) | 2011-02-02 | 2012-08-09 | 独立行政法人産業技術総合研究所 | Noble metal-oxide joined nanoparticles and method for high-purity production of the same |
US9675964B2 (en) | 2011-02-02 | 2017-06-13 | National Institute Of Advanced Industrial Science And Technology | Noble metal-oxide combined nanoparticle, and, method of producing the same with high purity |
CN102513103A (en) * | 2011-11-14 | 2012-06-27 | 浙江大学 | Preparation method of surfactant for photo-reduction method of Ag/TiO2 nano heterogenous junction by virtue of induction |
CN102716742A (en) * | 2012-07-06 | 2012-10-10 | 苏州大学 | Visible light degradation agent for dyeing wastewater treatment and preparation method of visible light degradation agent |
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