Kinetics of hydrogen production from illuminated CdS/Pt/Na2SO3 and ZnS/Pt/Na2S dispersions
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/Na2S dispersions (J. Phys. Chem., 1986, 90, 2388) and further examine the importance of ‘potential-determining’ ions in controlling the rate of H2 production.