Transition metal mixed oxide-embedded graphene oxide bilayers as an efficient electrocatalyst for optimizing hydrogen evolution reaction in alkaline media

Abstract

A novel electrocatalyst containing different percentages of iron-titanium mixed oxide onto graphene oxide (GO) support was prepared by embedding via the thermal decomposition method (TD) and was coated on a Cu substrate through facile electroless Ni–Co–P plating. The embedding of GO for improving the catalytic properties of the composites towards electrocatalytic hydrogen evolution reaction (HER) in alkaline media. The optimized mixed oxide-embedded GO exhibited superior electrocatalytic activity, which was attributed to the favourable surface structure and the electrochemical properties that were further confirmed by X-ray diffraction (XRD), HRTEM, SEM-EDX, XPS analysis, and electrochemical analysis. It was found that a benchmark current density of 6.02 mA cm⁻² has been achieved at an overpotential of 104 mV dec⁻¹ in 1 M KOH with a low Tafel slope of 37 mV dec⁻¹. The prepared catalyst was economically viable and its performance was consistent over a long duration of time. The remarkable activity of the FTG-incorporated electrode can be ascribed to the synergetic effect of Ti, Ni and P elements over the reactive sites and also due to the increased electrical conductivity. The binder-free coating of active ingredients over the working electrode surface also enriches the catalytic behaviour. These findings may open a new insight into the design and construction of novel, efficient, and durable electrocatalysts for HER.