Construction of 2D Bi2S3/CdS Nanosheet Arrays for Enhanced Photoelectrochemical Hydrogen Evolution

Abstract 2D Bi 2 S 3 /CdS nanosheet arrays have been constructed by a simple three-step method. Firstly, BiOI nanosheet arrays have been electrochemically grown on the surface of conductive FTO substrate and then converted into Bi 2 S 3 nanosheet arrays by ion exchange. Finally, CdS was hydrothermally deposited onto the surface of Bi 2 S 3 nanosheet arrays to form hybrid Bi 2 S 3 /CdS nanosheet arrays. The obtained hybrid heterojunction arrays have been used as photoanodes for photoelectrochemical hydrogen evolution and showed enhanced performance and prolonged stability. The photocurrent density of the elegant Bi 2 S 3 /CdS nanosheet arrays reaches 9.48 mA/cm 2 at 1.23 V RHE under an illumination of 100 mW/cm 2 from AM 1.5G sun simulator, which is more than ten times higher than that of the pure Bi 2 S 3 nanosheet arrays and the photocurrent density does not decline obviously after 4 h of continuous operation. Ultimately, a rational mechanism is proposed to elucidate the high performance and excellent stability of Bi 2 S 3 /CdS nanosheet arrays for photoelectrochemical cells. Graphic Abstract To obtain nanosheet arrays : Arrays of Bi 2 S 3 /CdS nanosheets on a FTO substrate are synthesized by electrodeposition, ion exchange and hydrothermal process. The Bi 2 S 3 /CdS nanosheet photoanodes show better photoactive and photostability compared to bare Bi 2 S 3 (CdS) nanosheets for photoelectrochemical splitting of water.