Effects of conditions for preparation of nano-CdS on photocatalysis activity
Cao Wei-liang Zhang Kai-hua Zhang Jing-chang (College of Science, Beijing University of Chemical Technology, Beijing 100029, China)
The effects of the conditions for preparation of nano-CdS on the photocatalysis activity, namely [Cd 2+]/[S 2-], superfluous S 2- and coating material PVP, were investigated through a photodegrading phenol solution as a probe reaction. The results show that whether or not there is PVP, [Cd 2+]/[S 2-] has no effect on the photocatalysis activity under the condition of low Cd 2+ and S 2- concentrations. The photocatalysis activity of the samples without PVP is higher than that of the samples with PVP when there is no superfluous S 2-. The difference in superfluous S 2- concentration determines the difference in photocatalysis activity and the higher S 2- concentration is, the lower photocatalysis activity is without PVP but superfluous S 2-. The difference in photocatalysis activity bears not only on the difference in superfluous S 2- concentration, but also on that whether there is PVP or not where there is superfluous S 2-. In addition, the conditions for preparation of nano-CdS with the optimal photocatalysis activity were summarized.