In-situ construction of 2D/1D Bi2O2S/Bi2S3 heterojunction from the topological transformation of Bi2O2S with significantly enhanced photoelectrochemical performance

Bi2O2S has gradually attracted the interest of researchers due to its excellent carrier mobility and light absorption property. However, its application in photoelectrochemical water splitting is very limited. In this work, hydrothermal treatment is performed on the obtained Bi2O2S film. Bi2S3 nanowires are in-situ evolved by the topological transformation of Bi2O2S, and heterojunction with atomic-level contact interface is constructed. The photocurrent density of Bi2O2S/Bi2S3 photoelectrode at 1.23 V vs. RHE is 3.82 mA/cm2, which is 14 times that of monomer Bi2O2S. The Bi2O2S/Bi2S3 heterojunction co-shared by Bi atoms has a close contact coupling interface, which stimulates stronger interfacial charge transfer. In addition, the 2D/1D morphology of the synthesized Bi2O2S nanosheets combined with Bi2S3 nanowires by fine tuning builds a channel for fast carrier transport. This study provides reference and inspiration for the preparation of highly active heterostructures, and expands new paths for the design and application of Bi2O2S based photoelectrodes.