Synthesis and exploration of NiSe2-GO composites as electrocatalysts with high-performance oxygen evolution reaction

Abstract

In this study, NiSe₂/GO composites were successfully synthesized by using a facile and effective chemical method to increase the catalytic activity and charge transfer efficiency for oxygen evolution reaction (OER). The structural analysis confirmed the successful preparation of NiSe₂ and NiSe₂-GO (10 %, 25 %) composites. Similarly, the morphology of NiSe₂ appeared to be nanocubes, whilst NiSe₂-GO (10 %, 25 %) composites revealed features comprising of both NiSe₂ nanocubes and GO sheets. The electrochemical performance of NiSe₂ and NiSe₂-GO (10 %, 25 %) composites was also investigated for enhanced OER. Among the synthesized compositions, NiSe₂–25 % GO demonstrated the most superior electrocatalytic performance, which exhibited a significantly lower Tafel slope (66 mV/dec at 10 mV/s). Electrochemical impedance spectroscopy (EIS) analysis further confirmed the high efficiency of NiSe₂–25 % GO, where a smallest semicircle in the Nyquist plot was observed. In terms of overpotential, NiSe₂–25 % GO achieved a remarkably low value of ∼350 mV, demonstrating superior catalytic efficiency compared to NiSe₂–10 % GO (∼500 mV) and pristine NiSe₂ (∼600 mV). The significantly reduced overpotential suggested that the NiSe₂–25 % GO material required the least energy input to drive the reaction at a given current density. This enhanced performance was attributed to the synergistic effect between NiSe₂ and GO, where the GO matrix provided a favorable pathway for electron transfer, while NiSe₂ acted as an active catalytic site for OER. These findings highlight NiSe₂–25 % GO as a highly effective and promising electrocatalyst for OER applications. Its superior charge transport characteristics, lower overpotential, and faster reaction kinetics make it a strong candidate for next-generation energy conversion and storage technologies.