Gold nanoparticles−supported Ti₃C₂ MXene nanosheets for enhanced electrocatalytic hydrogen evolution reaction

The hydrogen evolution reaction (HER) is being widely researched and developed because it is a favorable alternative to fossil fuels to produce renewable energy. The prominent development in HER is to construct an efficient electrocatalyst aside from Pt-based catalysts, with low economic cost. In this study, gold nanoparticles (Au NPs) supported MXene (Ti₃C₂T_x) was designed to enhance the performance of a HER electrocatalyst. The preparation of Au NPs-supported MXene was confirmed by XRD, FTIR, Raman spectroscopy, and UV-Vis DRS. The addition of Au NPs in the MXene structure is believed to improve its catalytic performance in the hydrogen evolution reaction. The catalytic performance data of Au/MXene exhibits a better result than non-modified MXene, with a lower overpotential (179.9 mV), onset potential (87.6 mV), Tafel slope (91 mV/dec), and a higher ECSA value (54 cm²), with excellent electrocatalyst stability after ten hours of reaction time. Furthermore, the Tafel slope data of Au/MXene indicated the reaction was using the Volmer-Heyrovsky path, with the rate-determining stage being that of the Heyrovsky mechanism. The increased activity as an electrocatalyst in HER was assigned to the synergetic effect between Au nanoparticles and MXene structures, which results in high-conductivity materials with enhanced ion diffusion and charge transfer.