Insights into the Effect of Reaction Temperature on Photocatalytic Hydrogen Evolution Over Cadmium Sulfide

Various morphologies of CdS photocatalysts, including one dimensional nanorods, and three dimensional nanosheet assembled flowers were prepared via a solvothermal process by tailoring the solvothermal temperature. CdS nanosheet assembled flowers prepared with lower temperature displayed excellent photocatalytic hydrogen production rate of 510 mu mol g(-1) h(-1) under visible light, which exceeded the CdS nanorods by more than 2.1 times. The enhanced photocatalytic activity was ascribed to the high purity, unique microstructure and band structure, which was favorable for transfer of photogenerated carriers and thus reduced the recombination of electron hole pairs. The reaction temperature had a significant effect on the hydrogen production of CdS, and the hydrogen production peak area sharply increased to 2.3 times of that at 6 degrees, only when the temperature was raised from 6 degrees to 17 degrees. The apparent hydrogen production rate of 17 degrees was 2.3 times that of the 6 degrees reaction, namely 1183 mu mol g(-1) h(-1). However, the true rate was 657 mu mol g(-1)h(-1), slightly greater than that of 6 degrees. Therefore, the reaction temperature of the system should be strictly controlled, and the fluctuation of the temperature will cause a change in the amount of hydrogen.