Two-Dimensional rGO-Supported Mo2S3 Catalysts with Tunable Electronic Structure for Efficient Electrochemical Water Splitting

The rational design of cost-effective and highly active electrocatalysts for overall water splitting remains a critical challenge for sustainable hydrogen production. Herein, we report a two-dimensional reduced graphene oxide (rGO)-supported Mo2S3 nanohybrid catalyst with a tunable electronic structure engineered through interfacial coupling. The intimate integration of Mo2S3 nanoflakes with conductive rGO nanosheet facilitates rapid electron transport, enhanced active site exposure, and optimized adsorption energetics for reaction intermediates. Structural and spectroscopic analyses confirm strong electronic interaction between Mo2S3 and rGO, leading to modulated charge density distribution and improved intrinsic catalytic activity. Electrochemical evaluations reveal significantly reduced overpotentials for oxygen evolution reaction (OER) with 166 mV overpotential at 10 mA cm−2 current density, along with favorable Tafel kinetics with 38.1 mV dec−1 and long-term operational stability in alkaline electrolyte. The rGO-Mo2S3-2||Pt-C cell delivers 10 mA cm−2 at 1.64 V, indicating efficient alkaline water splitting. The enhanced performance is attributed to synergistic effects arising from electronic modulation, enhanced active sites, and accelerated interfacial charge transfer.