Cu2O/Cu2S microstructure regulation towards high efficiency photocatalytic hydrogen production and its theoretical mechanism analysis

Abstract

Cu₂O with a cubic structure was prepared by a water bath method, and then a Cu₂O/Cu₂S core–shell material was obtained by the redox reaction of Cu₂O and Na₂S with the prepared cubic Cu₂O as a template and Na₂S·9H₂O solution as the reaction solution. At the same time, the effect of sulfidization time on the Cu₂O/Cu₂S structure and photohydrogen production performance was studied. The structure of the samples was further confirmed and characterized through SEM, HRTEM, XRD and XPS. The photohydrogen production properties of the Cu₂O/Cu₂S composites with different morphologies were tested. The flower-shaped hollow structure of Cu₂O/Cu₂S can be obtained by proper sulfidization, and the hydrogen production can reach 1076.95 μmol g⁻¹ after 5 h of illumination. Then, through photocurrent response and impedance spectrum tests and DFT calculations, it is proved that the Cu₂O/Cu₂S heterostructure can effectively improve the photoresponse ability and carrier transport properties. It was confirmed that the interfacial charge transfer in Cu₂O/Cu₂S helped increase the photocatalytic hydrogen production performance.