Bi_2S_3 anchored ZnS/ZnO nanorod arrays photoanode for enhanced visible light driven photo electrochemical properties

摘要

We report on the enhanced photoelectrochemical water splitting of hybrid ZnS/ZnO core-shell nanorod arrays functionalized with Bi2S3 nanosheets as photoanode. The ZnO nanorod arrays were prepared by a facile hydrothermal approach and sulphurized to form ZnS shell. Subsequently porous Bi2S3 nanosheets were arbitrarily decorated on the nanorod arrays by ionic adsorption and reaction method. Substantial enhancement in photocurrents with twofold increment is observed for hybrid photoanode compared to pristine counterparts. The structural and morphological properties of nano hybrid Bi2S3/ZnS/ZnO samples were analyzed by field emission scanning electron microscopy and X-ray diffraction. The higher wavelength shift in the absorption edge of Bi2S3/ZnS/ZnO photocatalyst was observed in diffuse reflectance UV-Visible spectra. The low temperature photoluminescence and impedance spectra of Bi2S3/ZnS/ZnO photoanode confirm that Bi2S3 functionalization reduces the recombination of electron-hole pair and facilitates barrier free charge transfer. The Bi2S3/ZnS/ZnO photoanode device exhibits photocurrent density of 220 mu A/cm(2) at 0.2 V vs. Ag/AgCl under the electrolyte solution at pH similar to 10.8. The resultant hybrid photoanode withhold good stability and maintain the facile charge carrier generation and separation. Bi2S3 topological nanosheets are responsible for the absorption of complete visible photons while ZnS/Bi2S3 inter-junction provides the robust electronhole pair separation at their interface due to infiltration pathway. The photoactive hybridization of Bi2S3/ZnS/ZnO provokes the enhanced donor charge density for efficient hydrogen evolution reaction. (C) 2020 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.