Activating BaWO4 ceramics through atomic-level Ni doping for enhanced hydrogen evolution reaction

Abstract

Achieving exceptional electrocatalytic activity in conventional low-cost materials is of great significance but remains highly challenging. BaWO₄ is recognized for its favorable stability and corrosion resistance in acidic/alkaline media, while intrinsically exhibiting limited activity for the electrocatalytic hydrogen evolution reaction (HER) due to its low electrical conductivity and insufficient active sites for optimal hydrogen adsorption/desorption kinetics. Herein, we report the successful activation of a BaWO₄ ceramic as a binder-free HER self-catalytic electrode via atomic-level Ni doping. The incorporation of trace amounts of Ni effectively modulates the electronic structure and surface morphology of the BaWO₄ self-catalytic ceramic, significantly enhancing charge transfer capability and exposing more catalytically active sites, thereby endowing it with improved intrinsic catalytic properties. As a result, the Ni-doped BaWO₄ (Ni_0.01-BaWO₄) ceramic electrode delivers an outstanding HER performance with a low overpotential of 122 mV at 10 mA cm⁻² in alkaline media, outperforming the undoped BaWO₄ (287 mV), and retains good durability with negligible degradation over 500 hours of continuous operation. Combined experimental analyses and density functional theory (DFT) calculations reveal that Ni doping lowers the energy barrier for H₂O dissociation by weakening H–OH adsorption and facilitating hydroxyl desorption, thereby improving overall HER kinetics. Notably, the catalyst exhibits superior structural integrity and long-term operational stability under harsh electrochemical and ultrasonic conditions. This work presents an effective approach to activate inert ceramic electrodes, achieving improved electrocatalytic activity and durability for practical HER applications.