Ar/NH3 plasma-tailored Pt–O–W interfaces enable sub-1% Pt loading self-supported electrode for enhanced hydrogen evolution reaction

The manufacturing of defect-engineered heterojunction catalysts is achieved using Ar/NH3 plasma treatment, which enhances the interaction between tungsten carbide (WC) and platinum (Pt) nanoparticles through the formation of Pt–O–W bonds, resulting in increased stability and improved performance. Specifically, a self-supporting carbon fiber-based electrode (p-Pt@WC@NCNTs@CC) is synthesized by loading WC onto carbon cloth, which is embedded with nitrogen-doped carbon nanotubes (NCNTs) serving as a support for ultra-low content Pt loading. Surface modification is performed using Ar/NH3 plasma. Compared to the commercial catalyst (20 wt. % Pt/C), p-Pt@WC@NCNTs@CC with only 0.98 wt. % Pt loading exhibited superior hydrogen evolution reaction performance in both alkaline and acidic media. In a 1 M KOH solution at a current density of 50 mA cm−2, p-Pt@WC@NCNTs@CC displays an overpotential of only 45 mV, significantly lower than that of 20 wt. % Pt/C (51 mV). In a 0.5 M H2SO4 solution, p-Pt@WC@NCNTs@CC requires overpotentials of only 7.5 and 40.5 mV to achieve current densities of 10 and 100 mA cm−2, respectively. This work presents a promising approach for synthesizing low-cost, efficient, and stable electrodes by employing surface modification through plasma treatment, wherein octahedral tungsten carbide is loaded onto NCNTs and coated with NCNT structures to enhance conductivity and structural stability.