Enhanced Hydrogen Evolution Reactions on Nanostructured Cu2ZnSnS4 (CZTS) Electrocatalyst

A novel and facile one-step sonochemical method is used to synthesize Cu2ZnSnS4 (CZTS) nanopartides (2.6 +/- 0.4 nm) as cathode electrocatalyst for hydrogen evolution reactions. The detailed morphology, crystal and surface structure, and composition of the CZTS nanostructures were characterized by high resolution transmission electron microscopy (HR-TEM), Selected area electron diffraction (SAED), X-ray diffraction, Raman spectroscopy, FTIR analysis, Brunauer Emmett-Teller (BET) surface area measurements, Electron dispersive analysis, X-ray photoelectron spectroscopy respectively. Electrocatalytic abilities of the nanoparticles toward Hydrogen Evolution Reactions (HER) were verified through cyclic voltammograms (CV) and Linear sweep voltammetry (LSV), electrochemical impedance spectroscopy (EIS), and Tafel polarization measurements. It reveals enhanced activity at lower onset potential 300 mV v/s RHE, achieved at exceptionally high current density 130 mA/cm(2), which is higher than the existing non-nobel metal based cathodes. Further result exhibits Tafel slope of 85 mV/dec, exchange current density of 882 mA/cm2, excellent stability ( >500 cycles) and lower charge transfer resistance. This sonochemically fabricated CZTSs nanoparticles are leading to significantly reduce cell cost and simplification of preparation process over existing high efficiency Pt and other nobel metal-free cathode electrocatalyst. (C) 2017 Elsevier B.V. All rights reserved.