Hydrogen evolution from water using CdS as photosensitizer

Colloidal chemical approaches are increasingly utilised for the preparation and stabilization of semiconductor nanoparticles. We prepared a colloidal CdS in excess of Na2S using a method described in the literature and determined the particle size from its absorption spectrum by Brus equation. A diameter of about 50 angstrom was calculated. For the stabilization of colloid we choosed from various tested polymers a 1% in weight copolymer (1/1), styrene/maleic anhydride. As redox catalyst we used colloidal Pt obtained "in situ " by irradiaton of PtCl6K2. We established the role of each of the system partners as: CdS concentration, Na2S excess, Pt catalyst concentration, the irradiation time, and the system temperature. We studied the in fluence of each participant to the hydrogen evolution in order to optimize this system. The formation of nanosize composite particles Cd1-xZnxS showed an increasing of H-2 amount generated under irradiation, in comparison with CdS particles. The results obtained permitted us to calculate the turnover number (TO) of the system.