A study on preparation coated-CdS photocatalyst and continuous reaction system

CdS is the most wildly used photocatalyst for effective hydrogen production at present. However there are two major problems existed that restricted its industrial application. One is the fixation of photocatalyst, and the other is to design a continuous photocatalytic reactor. The two problems were studied as follows: Two kinds of beading (d=100 nm and d=500 nm) coated-CdS were prepared by calcining with different temperature. The samples were characterized by several methods. Coalescent intensity of CdS-beading was analyzed by continuous stir for 20 hours, then weigh the dried samples to determine the weight removed in continuous stir. All the prepared fixed-CdS photocatalyst were characterized by XRF and their photocatalytic activity were evaluated by H₂ evolution from water under visible light. The thickness of CdS on the beading surface was estimated by a simple mathematical model. A novel continuous reactor was designed and manufactured for the experimental production hydrogen. Then the fixed photocatalyst was used to test the performance of the reactor, and found the best experimental parameter (the rotate speed of magnetic stirrer is 700 r/min, pump speed is 20 r/min).