纳米硫化镉制备条件对光催化活性的影响

Effects of conditions for preparation of nano-CdS on photocatalysis activity

以光降解苯酚溶液为探针反应 ,考察了 [Cd2 + ]/ [S2 -]、表面过剩S2 -和表面修饰剂PVP等纳米硫化镉(CdS)晶粒制备条件对其光催化活性的影响。结果表明 ,在Cd2 + ,S2 -浓度较低时 ,无论PVP是否存在 ,[Cd2 + ]/[S2 -]的不同均不影响光催化活性 ;当表面无过剩S2 -时 ,不加PVP的样品光催化活性优于加入PVP的样品 ;当表面有过剩S2 -但无表面修饰剂PVP时 ,光催化活性的差异主要由过剩S2 -浓度不同引起的 ,过剩S2 -浓度越高样品的光催化活性越低 ;当表面有过剩S2 -时 ,样品光催化活性的差异不仅与过剩S2 -浓度有关 ,还与PVP存在与否有关。此外 ,总结了光催化活性最佳时CdS催化剂的制备条件。

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.