Synthesis of Visible Light Active Photocatalyst Controlling the Nanostructure of Layered Titanate

控制层状钛酸盐纳米结构的可见光活性光催化剂的合成

• 批准号: 12450349
• 负责人: SATO Tsugio
• 金额: $ 9.22万
• 依托单位: Tohoku University
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (B)
• 财政年份: 2000
• 资助国家: 日本
• 起止时间: 2000 至 2002
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-12450349/
• 关键词: H_2Ti_4O_9; HTaWO6; TiO_2; CbS; Nanocomposite; Intercalation; Photocatalytic activity; Visible light reactivity; 白金; 光化学特性; チタニア; 光触媒; 可視光; 遷移金属付活; ルチル; 酸化鉄; 水熱晶析反応; イオン交換反応

Layered titanate, H_2Ti_4O_9 incorporating CdS, Fe_2O_3 and TiO_2, H_2Ti_4O_9 simultaneously alloyed with Cu^<2+> and Nb^<5+> or Ta^<5+>, and layered HTaWO_6 incorporating TiO_2 and Pt were prepared and their photocatarytic activities under visible light irradiation were investigated. All samples possessed photocatalytic activity for the hydrogen evolution from sodium sulfide or methano aqeous solution under visible light irradiation (λ 0x(3E) 400 nm). HTaWO_6 was unstable in methanol aqueous solution under UV light irradiation, but HTaWO_6/(TiO_2,Pt) nanocomposite was stable and showed visible light active photocatalytic activity for evolving hydrogen gas from methanol aqueous solutionn. The excellent photocatalitic activity of semiconductor particles incorporated was attributed to the charge separation by guest to host electron transfer. By analyzing the fluorescence life times of CdS and TiO_2 incorporated in H_2Ti_4O_9 and H_4Nb_6O_<17>, it was confirmed that photoinduced electron in CdS and/or TiO_2 in the interlayer quickly transfer to the host layers. The electron transfer rate constant from CdS to H_2Ti_4O_9 and/or H_4Nb_6O_<17> were determined as ca. 10^6 sec^<-1> and those from TiO_2 to H_2Ti_4O_9 and H_4Nb_6O_<17> were 10^8 sec^<-1>.

制备了层状钛酸盐、掺入CdS、Fe_2O_3和TiO_2的H_2Ti_4O_9、同时与Cu^<2+>和Nb^<5+>或Ta^<5+>合金化的H_2Ti_4O_9以及掺入TiO_2和Pt的层状HTaWO_6，并考察了它们的光催化活性。研究了可见光照射下所有样品都具有光催化析氢活性。可见光照射下硫化钠或甲醇水溶液(λ 0x(3E) 400 nm)在甲醇水溶液中HTaWO_6在紫外光照射下不稳定,而HTaWO_6/(TiO_2,Pt)纳米复合材料表现出可见光活性光催化活性。从甲醇水溶液中析出氢气的优异光催化活性归因于掺入的半导体颗粒。通过分析H_2Ti_4O_9和H_4Nb_6O_<17>中掺入的CdS和TiO_2的荧光寿命，证实了中间层中CdS和/或TiO_2中的光生电子快速转移到主体层。从CdS到H_2Ti_4O_9和/或H_4Nb_6O_<17>的电子转移速率常数确定为：约10^6秒^<-1>，而从TiO_2到H_2Ti_4O_9和H_4Nb_6O_<17>的时间为10^8秒^<-1>。