Hydrogen photoproduction from hydrogen sulfide on Bi2S3 catalyst

Films of polycrystalline Bi2S3 have been prepared onto bismuth and platinum substrates by electrodeposition from an aqueous sulfide bath. The films were thin, uniform and well adhered. Bi2S3 is a direct band gap semiconductor with a value of 1.28 eV optimally matched with the solar spectrum. The photoelectrochemical study was undertaken for the generation of hydrogen by using illuminated n-Bi2S3 particles; it was found that hydrogen evolution depends highly on the synthesis method of powder. Impregnation of platinum onto Bi2S3 shows a production enhancement of about 25%. The most active photocatalyst, prepared by a solvent thermal process and loaded with Pt in 0.1 M S2− alkaline electrolyte, yields 2.13×10−2 ml mg−1 of H2 after 4 h of irradiation with the visible output of a 500 W halogen lamp.