Zig-zag Ag_2S nanostructures for superior optical absorption and photoelectrochemical water splitting performance

摘要

Here, we report synthesis of Ag2S nanostructures of zig-zag geometry to achieve the improved photo electrochemical (PEC) water splitting response for hydrogen generation. A two-step process was utilized for the fabrication of working electrodes. The synthesis of zig-zag nanorods was carried out using glancing angle deposition followed by sulfurization. The PEC performance was studied by varying the number of zig-zag arms of Ag2S. The as-prepared four arm Ag2S zig-zag electrodes exhibited superior optical absorption, as well as photocurrent density of 3.04 mA/cm(2) (at 1 V vs Ag/AgCl), compared to one arm Ag2S nanorods with minimum charge transfer resistance at the semiconducting electrode/electrolyte interface. The improved photocurrent density of four arm Ag2S zig-zag nanorods electrode was attributed to increased optical trapping and hence, effective absorption of light due to its wavy structure. The theoretical simulations based on rigorous coupled wave analysis were performed to understand the light absorption mechanism for the zig-zag Ag2S nanorods structures. This work provides a simple and effective approach towards the development of an efficient PEC electrode by tuning the morphology of nanostructured materials. (c) 2021 Elsevier Ltd. All rights reserved.