Surface defect engineering via acid treatment improving photoelectrocatalysis of β-In2S3 nanoplates for water splitting

Hydrogen generation via photoelectrocatalytic water splitting is one of the promising ways to achieve clean energy. In the process of photoelectroncatalysis, charge transfer is of the key for enhancing the efficiency of water splitting. In this work, surface-defective beta-In2S3 nanoplates arraying on fluorine-doped tin dioxide (FTO) glass were successfully prepared via a simple solution method with acid treatment. When used as photoanode, the beta-In2S3 nanoplates with hydrochloric acid treatment showed an enhanced photoelectrocatalytic reaction activity for water splitting. The photocurrent density reached 1.26 mA cm(-2) at 1.23 V versus reversible hydrogen electrode (vs RHE) under the irradiation of 100 mWcm(-2) without sacrifice agent, which was about 8.5 times higher than that of the beta-In2S3 photoanode with no acid treatment. The max photoelectric conversion efficiency of 0.4% was achieved at a very low potential (0.45 V vs RHE). In-depth analysis showed that the enhanced photoelectrocatalysis was mainly due to the promotion of charge transfer by the produced surface defect engineering during the acid treatment process.