Kinetics of hydrogen production from illuminated CdS/Pt/Na 2SO3 and ZnS/Pt/Na2S dispersions

Abstract

The rate of production of molecular hydrogen upon illumination of transparent CdS/Pt/Na2SO3 and ZnS/Pt/Na2S dispersions has been examined as a function of the intial donor concentration. The maximum rate of H2 production was found to be relatively insensitive to the concentration of Na2SO3 in the range 10-2-1 mol dm-3 whereas, for Na2S as donor, a maximum in the production rate is observed at ca. 8 × 10-3 mol dm-3. The results complement an earlier study on CdS/Pt/Na 2S dispersions (J. Phys. Chem., 1986, 90, 2388) and further examine the importance of 'potential-determining' ions in controlling the rate of H 2 production.