Fabrication of MoS2/rGO hybrids as electrocatalyst for water splitting applications

Abstract

Environmental degradation and energy constraint are important risks to long-term sustainability in the modern world. Water splitting is a vital approach for environmentally friendly and sustainable energy storage, providing a clean way to produce hydrogen without pollutants. Preparing a catalyst that is active, bifunctional, and durable for water splitting is a difficult task. We addressed the difficulty by creating a bifunctional heterogeneous catalyst, MoS₂/rGO, with an ideal weight percentage of 5 wt% by a hydrothermal process. The optimized sample showed exceptional electrocatalytic activity, requiring an overpotential of 242 mV and 120 mV to achieve a current density of 10 mA cm⁻² in the Hydrogen Evolution Reaction (HER) and Oxygen Evolution Reaction (OER). Furthermore, our synthesized catalyst was validated for its exceptional water-splitting capacity, with the optimized sample showing low Tafel slope values of 59 mV dec⁻¹ for HER and 171 mV dec⁻¹ for OER. The significant OER and HER activity seen in the 5 wt% MoS₂/rGO hybrid, compared to other hybrids, is due to the many catalytic active sites that aid in charge and electron transport, as well as the synergistic interaction between MoS₂ and rGO.