LAUSR

Abstract In this paper, the toxic H2S was transformed efficiently into valuable S and H2O2 and its chemical reaction energy was converted into electric energy through a self-driven photoelectrocatalytic(PEC) system, which consisted of a microporous gas diffusion electrode(GDE) and a self-bias photoanode. In the cathode region, high yield of H2O2 up to 0.8 mmol/L/h, was achieved because of the fast gas diffusion and direct two-electron reduction of molecular oxygen on the microporous GDE cathode. In the anodic region, H2S was completely converted into S without persulfide based on a I−/I3− redox system and the production rate of S recovery was about 0.60 mmol/h, 42 times higher than before. The remarkable catalytic efficiency also benefited from the self-bias design of photoanode, which included a front photoanode of WO3 and a rear Si photovoltaic cell (Si PVC). The constituted self-driven PEC system could accelerate the charges separation and increase the electron transfer rate of PEC cell. In addition, electricity was generated simultaneously, with a maximum power density of 0.19 mW/cm2. The proposed self-driven PEC cell system offers an efficient, complete and sustainable way for H2S resourcization.