采用共沉淀法制备了Cd0.53Zn0.47S固溶体光催化剂,以光还原沉积法负载Pt,水解正硅酸乙酯负载SiO2,得到了负载Pt的SiO2复合光催化剂SiO2/Pt-Cd0.53Zn0.47S,并研究了水解pH值对其催化活性的影响.通过X射线衍射(XRD)、比表面(BET)、荧光光谱(PL)、紫外-可见漫反射光谱(UV-Vis DRS)和扫描电镜(SEM)等测试技术对催化剂进行了表征.结果表明,SiO2复合光催化剂有效地抑制了Pt-Cd0.53Zn0.47S光催化过程中发生的光腐蚀和粒子团聚,促使光生电子和空穴分离,从而使可见光制氢催化剂活性和稳定性大大提高.
Cd0.53Zn0.47S was prepared by a coprecipitation method. Pt was loaded onto Cd0.53Zn0.47S by photodeposition method. SiO2 was deposited onto Cd0.53Zn0.47S by hydrolysis of the tetraethylorthosilicate (TEOS), and the effect of the hydrolysis pH on the activity of the catalysts was studied. The samples were characterized by X-ray diffraction (XRD), BET surface area, photoluminescence (PL), UV-Vis diffusive reflectance spectroscopy (UV-Vis DRS), and scanning electron microscope (SEM) techniques. The composite SiO2 prevented effectively photocorrosion and coalescence of Pt-Cd0.53Zn0.47S nanoparticles during the photocatalytic reaction, and improved the charge separation of photogenerated electrons and holes. Therefore, the stability and the activity of Pt-Cd0.53Zn0.47S for photocatalytic hydrogen generation under visible light irradiation were improved greatly.