Effect of 100 KeV Ar+ ion beam irradiation on ZnO thin films - Influence of morphology vis-a-vis electrode/electrolyte interface and its impact on photoelectrochemical water splitting

The present study attempts quantitative determination of changes in the morphological surface features viz. fractal dimension, lower and upper cut off length scale through Power Spectral Density analysis prior to and after irradiation of 100 KeV Ar+ ion beam at incidence angles of 0 degrees, 40 degrees and 60 degrees on ZnO thin films. All the unirradiated and irradiated samples are subjected to photoelectrochemical characterization and a correlation between photo electrochemical performance and morphological parameters is established. Sample irradiated at 40 degrees angle at the fluence of 5 x 10(16) ions/cm(2) is found to possess maximum fractal dimension of 2.72, lower and upper cut off length scale of 3.16 nm and 63.00 nm respectively. This sample exhibits maximum photocurrent density of 3.19 mA/cm(2) and applied bias photon-to-current efficiency of 1.12% at 1.23 V/RHE. Hydrogen gas collected for duration of 1 h for the same sample was -4.83 mLcm(-2). (C) 2021 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.