Laser-induced graphene nano-anchored WS2/WO3 heterostructures for electrocatalytic oxygen evolution reaction

Abstract

Tailoring surface components and nanostructures via integration of dual transition metal heteroatoms is a highly effective technique for the design and synthesis of electrocatalysts with superior performance. In this study, we report WS₂/WO₃ nanostructure enriched with sulphur and oxygen vacancies, embedded within laser-induced graphene (LIG) as carbon support, to improve alkaline and seawater splitting applications for the oxygen evolution reaction (OER). The LIG-WS₂/WO₃ nanohybrid demonstrates high OER activity and improved stability due to the synergistic interaction between LIG, WS₂, WO₃, and optimized proportion of sulphur and oxygen vacancies, which facilitates efficient charge transfer, reduces recombination losses and allows significant tuning of various electrocatalytic parameters as a function of annealing temperature. The optimized sample, LWSO@450, exhibits excellent electrocatalytic activity with a low overpotential of 350 mV at a current density of 50 mA/cm2 and an exceptionally low Tafel slope of 33 mV/decade in an alkaline medium. Moreover, the high electrochemically active surface area of 134 cm2, mass activity of 60 A/g, and turnover frequency of 0.012 s⁻1 indicate a substantial number of active sites. These findings highlight the considerable potential of this catalyst in various electrochemical domains, particularly in energy conversion, and other renewable energy systems, due to its cost-effectiveness, availability, and scalability.