硫化镉光催化氧化二苯甲醇的反应及二次电子转移在反应中的作用

Photo-Induced Catalytic Oxidation of Benzhydrol by CdS and the Effects of Secondary Electron Transfer Reaction

本文报道紫精化合物及亚硫酸盐在硫化镉光催化氧化二苯甲醇及其它芳香醇反应中的作用。认为紫精化合物通过二次电子转移作为反应中负氧离子(O_2^-)的中继体。亚硫酸盐通过与硫化镉的价带发生电子转移作用减少光生电子-空穴对的复合,提高半导体的光催化效率,同时对硫化镉的腐蚀有抑制作用。认为提高半导体光催化效率的途径在于有效地促使光生电荷分离。

With CdS powder as photo-catalyzer, the oxidation of benzyl alcohol derivatives (benzhydrol, benzyl alcohol, benzoin) were investigated. Based on the secondary electron transfer principle, certain attempts were taken to accelerate the CdS photo-induced eatalytic oxidations. Alkyl viologens are good electron mediator of O_2^- in CdS photocata- lytic reaction. It was demonstrated that sulfite is a sufficient hole scavenger to prevent the photocorrosion of CdS and it can promote the reaction. It seems that the methods leading to the separation of photogenarated e^-/h^+ pairs can increase the photocatalytic efficiency.