Simultaneous hydrogen production and decomposition of H2SH2S dissolved in alkaline water over CdS–TiO2CdS–TiO2 composite photocatalysts under visible light irradiation

A process of simultaneous hydrogen production and H2SH2S removal has been investigated over a highly active composite photocatalyst made of bulk CdS decorated with nanoparticles of TiO2TiO2, i.e. CdS(bulk)/TiO2TiO2. The photocatalytic activity was evaluated for hydrogen production from aqueous electrolyte solution containing H2SH2S dissolved in water or alkaline solution under visible light irradiation. The rate of hydrogen production from the H2SH2S-containing alkaline solution was similar to the rate obtained from photocatalytic hydrogen production from water containing sacrificial reagents (Na2S+Na2SO3)Na2S+Na2SO3) in the similar concentration. The isotope experiment was carried out with D2OD2O instead of H2OH2O to investigate the source of hydrogen from photocatalytic decomposition of H2SH2S dissolved in H2OH2O or alkali solution under visible light. Hydrogen originated from both H2SH2S and H2OH2O when the reaction solution contained H2SH2S absorbed in alkaline water.