Chloride ion: A promising hole scavenger for photocatalytic hydrogen generation

Abstract The investigation pertains to elucidation of promising role of in-situ chloride ions generated during the photoreduction of HAuCl 4 as an internal sacrificial donor for photocatalytic hydrogen generation. The hydrogen evolution rate (HER) observed was 4.16 mmol h −1 using in-situ route of photocatalyst formation which is significantly higher than the conventional route of formation of recovered photocatalyst. This unreported and unprecedented enhancement is explained on the basis of role of chloride ions released from the gold precursor. Experimental data inferring the effect of chloride ions on photocatalytic hydrogen generation using Au TiO 2 are also briefly explained. The role of anionic sacrificial donors suggests several potential possibilities for their applications in photocatalysis considering their presence in wastewater as well as their low cost and abundant availability. The work also introduces one-step photodeposition and hydrogen generation process against traditional recovered photocatalyst, wherein the catalysts were prepared first by normal route of photodeposition, recovered and then employed for hydrogen generation.