A bicomponent TiO2/SnO2 particulate film for photocatalysis

Plasma-enhanced chemical vapor deposition (PECVD) was used in the preparation of a series of bicomponent TiO2/SnO2 particulate films. The photocatalytic activities of the films are evaluated by photodegradation of phenol in solution. When both the TiO2 and SnO2 components of the bicomponent TiO2/SnO2 catalysts are accessible to reactants at the catalyst surface, photocatalytic degradation efficiencies are improved as compared to those obtained with TiO2 films. When this condition prevails, the two components are believed to act in a cooperative manner by increasing the degree of charge carrier separation sufficient to reduce recombination, while simultaneously allowing sufficient time for photoelectrons and photoholes on the catalyst surface to form reaction intermediates (for example, the superoxide radical ion, O-2(.-), formed by reaction of O-2 With photoelectrons, and the phenol radical, formed by reaction of phenol with photoholes or OH. radicals) which cooperatively participate in later stages of the degradation process.