Molybdenum Sulfo-Selenide Nanoarrays Anchored on Reduced Graphene Oxide for Efficient Hydrogen Evolution and...

Transition metal dichalcogenide two-dimensional (2D) alloys are evolving as auspicious constituents for energy storage and electrocatalytic energy conversion owing to their distinctive physicochemical characteristics. Heterostructuring these materials with other 2D compounds represents an effective strategy for enhancing charge storage kinetics and optimising water-splitting reactions. This work elaborates the synthesis of defective molybdenum sulfo-selenide/reduced graphene oxide (MoSeS/rGO) hybrids via a simple hydrothermal process, specifically engineered for energy storage and hydrogen evolution applications. Surface characterization reveals nano-dot-embedded pine-cone-like domains, confirming the formation of MoSeS integrated within an rGO hybrid architecture. Electrochemical investigations demonstrate that this architectural design significantly reduces the energy barrier and mitigates structural degradation during electrolyte ion diffusion. Notably, the MoSeS/rGO hybrid demonstrates high asymmetric capacitance of 306 F g^-1 with 109 Wh kg^-1 specific energy at 800 W kg^-1 specific power and admirable cycling stability of 93% preservation over 10 000 cycles. Furthermore, the MoSeS/rGO hybrid displays remarkable hydrogen evolution reaction behaviour, achieving overpotentials of 48 mV in potassium hydroxide  and 43 mV in sulfuric acid at -10 mA cm^-2. These improved electrochemical performances are ascribed to the hierarchical layered structure of MoSeS anchored on rGO, where strategic defect engineering yields a robust hybrid framework that is highly effective for both high-performance supercapacitors and efficient hydrogen evolution kinetics.