Paulraj Gnanasekar, Dharmaraj Periyanagounder, Purushothaman Varadhan
Nov 4, 2019
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0
Influential Citations
33
Citations
Journal
ACS applied materials & interfaces
Abstract
In recent days, 2-dimensional (2D) niobium disulphide (NbS2) with the near-zero Gibbs free energy and superlative acid electrolyte stability has provoked a great deal of interest towards hydrogen evolution reaction (HER) electrocata-lyst due to its active basal and edge sulphur sites. Here in, we developed a single step method for the direct deposition of 2D-NbS2 on high-aspect ratio topographies of silicon nanowires (NWs) by chemical vapor deposition for the appli-cations in HER electrocatalyst. The resultant 2D-NbS2 electrocatalyst demonstrates the HER overpotential of ~74mV vs. RHE (reversible hydrogen electrode) @ 1 mA/cm2 under acidic conditions and stable for more than 20 hours. More importantly, we developed the Si NWs array based photoelectrochemical water-splitting system with the direct deposi-tion of 2D-NbS2 as HER catalyst. The resultant 2D-NbS2-Si NWs photocathode system demonstrates improved charge transfer characteristics at the Si-NbS2 interfaces that leads to an enhanced turn on potential (from 0.06 V to 0.34 V vs. RHE) with the current density of -28 mA/cm2 at the 0 V vs. RHE. The results evidence the synergistic effect of 2D-NbS2 electrocatalysts that addresses poor surface kinetics of Si towards solar water electrolysis. Our comprehensive studies reveal that NbS2 as a new class of photoelectrochemical co-catalyst for efficient solar HER performance by promoting the charge transfer process with prolonged acid stability.