Constructing Z-scheme type photocatalyst is an efficient way to improve the charge separation efficiency and enhance the photocatalytic activity. In this report, the Cd：TiO2 nanoparticles are prepared via the sol-gel...Constructing Z-scheme type photocatalyst is an efficient way to improve the charge separation efficiency and enhance the photocatalytic activity. In this report, the Cd：TiO2 nanoparticles are prepared via the sol-gel route and employed as a starting material. When it was reduced by NaBH4 at 300°C,the surface oxygen vacancies were produced and Cd2＋ was reduced into metal Cd0 nanoparticle（denoted as R-Cd：TiO2）.Subsequently, the formed R-Cd：TiO2 was treated with thioureain the hydrothermal reaction. Through the decomposition of thiourea, the oxygen vacancies were refilled by S2- from thiourea to form S：TiO2/TiO2（d-TiO2） and Cd was partially converted into CdS to form CdS/Cd/d-TiO2 composite. The formed CdS/Cd/d-TiO2 composite exhibits improved photocatalytic activity. Under visible light irradiation（λ〉400 nm）,the H2 production rate of CdS/Cd/d-TiO2 reaches 119 μmol h-1 with 50 mg of photocatalyst without any cocatalyst, which is about 200 and 60 times higher than that of S：TiO2/TiO2（0.57 μmol h-1）, CdS（2.03 μmol h-1） and heterojunction CdS/d-TiO2（2.17 μmol h-1） materials, respectively. The results illustrate that metal Cd greatly promotes the charge separation efficiency due to the formation of Z-scheme type composite. In addition, the photocatalytic activity in the visible light region was dramatically enhanced due to the contribution of both CdS and d-TiO2. The method could be easily extended to other wide bandgap semiconductors for constructing visible light responsive Z-scheme type photocatalysts.展开更多
基金financial support from the National Natural Science Foundation of China (21671011)Beijing High Talent Program+5 种基金Beijing Natural Science Foundation (KZ201710005002)China Postdoctoral Science FoundationBeijing Postdoctoral Research FoundationDongguan Program for International S&T Cooperationsupport from China Scholarship Councilsupported by the National Science Foundation (DMR-1506661, Feng P)
文摘Constructing Z-scheme type photocatalyst is an efficient way to improve the charge separation efficiency and enhance the photocatalytic activity. In this report, the Cd：TiO2 nanoparticles are prepared via the sol-gel route and employed as a starting material. When it was reduced by NaBH4 at 300°C,the surface oxygen vacancies were produced and Cd2＋ was reduced into metal Cd0 nanoparticle（denoted as R-Cd：TiO2）.Subsequently, the formed R-Cd：TiO2 was treated with thioureain the hydrothermal reaction. Through the decomposition of thiourea, the oxygen vacancies were refilled by S2- from thiourea to form S：TiO2/TiO2（d-TiO2） and Cd was partially converted into CdS to form CdS/Cd/d-TiO2 composite. The formed CdS/Cd/d-TiO2 composite exhibits improved photocatalytic activity. Under visible light irradiation（λ〉400 nm）,the H2 production rate of CdS/Cd/d-TiO2 reaches 119 μmol h-1 with 50 mg of photocatalyst without any cocatalyst, which is about 200 and 60 times higher than that of S：TiO2/TiO2（0.57 μmol h-1）, CdS（2.03 μmol h-1） and heterojunction CdS/d-TiO2（2.17 μmol h-1） materials, respectively. The results illustrate that metal Cd greatly promotes the charge separation efficiency due to the formation of Z-scheme type composite. In addition, the photocatalytic activity in the visible light region was dramatically enhanced due to the contribution of both CdS and d-TiO2. The method could be easily extended to other wide bandgap semiconductors for constructing visible light responsive Z-scheme type photocatalysts.
