光催化分解水制氢用CoO/CaTiO3催化剂——制备方法及光催化作用机理探讨

以钛酸四丁酯的水解产物TiO(OH)₂和硝酸钙为原料，固态反应合成CaTiO₃.研究了负载组分对CaTiO₃光催化分解水制氢活性的影响，结果表明：CoO、NiO、Ag均对CaTiO₃的活性有促进作用，其中CoO的作用最为明显.考察了负载钴后处理方法对CaTiO₃活性的影响，并利用XRD、XPS、SEM等手段对负载催化剂进行了表征.研究显示：CaTiO₃被Co(NO₃)₂溶液浸渍后，经加热分解，500 ℃氢气还原，再于200 ℃氧气氧化处理后，得到均匀分布于CaTiO₃表面、金属钴表面覆盖CoO的负载结构，这种结构使催化剂表现出较高的活性.探讨了负载型催化剂CoO/CaTiO₃的光催化作用机理.

CoO/CaTiO3 Catalyst for photocatalytic decomposition of water to hydrogen--preparation method and investigation of photocatalysis mechanism

CaTiO₃ powder was synthesized by solid-state reaction of calcium nitrate with TiO(OH)₂ formed by hydrolysis of tetrabutyl titanate.The effect of supported promoters on the photocatalytic activity of CaTiO₃ for the decomposition of water to hydrogen was studied, and the results showed that the photocatalytic activity of CaTiO₃ could be promoted by CoO, NiO and Ag, and that the effect of CoO was the best.The influence of the treatment method for the supported samples on photocatalytic activity of CaTiO₃ was investigated and the samples were characterized by means of XRD, XPS and SEM.The results showed that the structure of Co-covering CoO distributing uniformly over the surface of CaTiO₃ was obtained after Co(NO₃)₂-impregnated CaTiO₃ sample underwent thermal decomposition, reduction by hydrogen at 500 ℃,and then oxidation by oxygen at 200 ℃, and the catalyst with this structure showed higher activity.The photocatalysis mechanism of CoO/CaTiO₃ was discussed.