Pt-enhanced WO3 nanoparticles for efficient hydrogen production: synthesis and electrochemical evaluation.

In this study, Pt/WO₃ nanoparticles were synthesized using a simple room-temperature impregnation-reduction method and characterized by advanced techniques including ICP, TEM-EDX, FE-SEM-EDX, and XRD. The ICP-OES analysis confirmed a 1.0 wt. % Pt loading on the WO₃ support. TEM and FE-SEM analyses revealed that the Pt nanoparticles were well dispersed with an average size of approximately 3.7 nm. The XRD patterns showed characteristic WO₃ peaks without any detectable Pt diffraction peaks, indicating the high dispersion of Pt. Electrochemical evaluations demonstrated that the Pt/WO₃ catalyst exhibited outstanding hydrogen evolution reaction (HER) performance, with -27.8 mV vs. RHE onset potential and -37.4 mV overpotential at 10 mA.cm^-2, outperforming bare WO₃. The Tafel slope (b) of 68.6 mV·dec^-1 indicates efficient reaction kinetics following the Volmer-Heyrovsky pathway. The impedance analysis confirmed efficient charge transfer, with a b value of 69.7 mV.dec^-1. The ECSA was calculated as 8.575 cm², highlighting the high surface activity of the catalyst. Stability tests showed minor degradation but retained significant catalytic activity. This work emphasizes the potential of Pt/WO₃ as an environmentally friendly, cost-efficient catalyst with promising applications in HER, providing a scalable and effective approach to hydrogen production.