Electrochemical Profiling and Solvothermal Approach to High Performance Chromium Chalcogenides for Efficient Water splitting

Abstract

This study explores the electro-catalytic activity of solvothermally synthesized chromium chalcogenides (Cr2S3, Cr2Se3, Cr2Te3) for Water Splitting. Extensive characterization (X-Ray Diffraction, X-ray Photoelectron Spectroscopy, Energy Dispersive X-Ray, and Scanning Electron Microscope) revealed the structural and morphological properties of the catalysts. Notably, Cr2S3 exhibited superior performance in both the Oxygen Evolution Reaction and Hydrogen Evolution Reaction compared to its selenium and tellurium counterparts. In Linear Sweep Voltametry measurements, Cr2S3 demonstrated significantly lower overpotentials of 232.6 mV (OER) at 10 mA/cm², and 87.1 mV (HER) at -10 mA/cm², surpassing Cr2Se3 (270 mV and 103 mV) and Cr2Te3 (288 mV and 402 mV) at the same current density. Furthermore, Cr2S3 displayed higher charge transfer resistances in both OER and HER, evidenced by cyclic voltammetry (300 mA/cm² for Cr2S3 vs. 220 mA/cm² and 180 mA/cm² for Cr2Se3and Cr2Te3, respectively). Electrochemical impedance spectroscopy (EIS) confirmed this trend, revealing a lower charge transfer resistance (Rct) for Cr2S3 in both OER and HER. Tafel slopes further highlighted the exceptional activity of Cr2S3, with values of 70.98 mV/dec⁻¹ (OER) and 65.47 mV/dec⁻¹ (HER) compared to Cr2Se3 (75.34 mV/dec⁻¹ and 71.89 mV/dec⁻¹) and Cr2Te3 (94.16 mV/dec⁻¹ and 88.21 mV/dec⁻¹). This superior performance underscores the potential of Cr2S3 as a highly efficient and durable electrocatalyst for Water Splitting applications.