Vertically aligned ZnO/In₂S₃ core/shell heterostructures with enhanced photoelectrochemical properties

ZnO/In₂S₃ core/shell heterostructures were successfully synthesized through a successive ion layer absorption and reaction (SILAR) method. The thickness of In₂S₃ shells were adjusted from 6.8 to 36.1 nm by adopting different SILAR cycles. Compared with pure ZnO NRs, the ZnO/In₂S₃ core/shell NRs presented better light absorption, higher photocurrent density and enhanced incident photon-to-current conversion efficiency (IPCE). Both the highest photocurrent density and IPCE of obtained ZnO/In₂S₃ core/shell heterostructures were almost three times higher than that of pristine ZnO NRs. The PL spectra, i–t curves, EIS plots, Mott–Schottky plots and ECSA curves were also recorded to investigate the influence of the In₂S₃ deposition on the photoelectrochemical (PEC) performance of ZnO NRs. The In₂S₃ nanoparticles deposited on the surface of ZnO NRs enhanced the light absorption of the heterostructures and facilitated the separation of photogenerated electron–hole pairs, eventually resulting in the enhanced PEC performance. The preparation of ZnO/In₂S₃ core/shell heterostructures by the simple SILAR method would increase the possibility for its practical application of photoelectrodes in the future.