Interlayer-bonded Ni/MoO2 electrocatalyst for efficient hydrogen evolution reaction with stability over 6000 h at 1000 mA cm−2

The mechanical stability of the catalytic electrodes used for hydrogen evolution reactions (HER) is crucial for their industrial applications in anion exchange membrane water electrolysis (AEM-WE). This study develops a corrosion strategy to construct a self-supported electrocatalyst (Int-Ni/MoO₂) with high mechanical stability by anchoring the Ni/MoO₂ catalytic layer with a dense interlayer of MoO₂ nanoparticles. The Int-Ni/MoO₂ exhibits a strengthened homostructural interface between the interlayer and catalytic layer, preventing the detachment of the catalyst during ultrasonic treatment. The blade-shaped catalytic layer reduces bubble shock and potential fluctuations at high current densities up to -6000 mA cm^-2. As a result, the Int-Ni/MoO₂ electrode exhibits a low overpotential of 73.2 ± 14.2 mV and long-term stability for 6000 h at -1000 mA cm^-2 in a 1 M KOH solution. The Int-Ni/MoO₂ assembled AEM-WE device demonstrates long-term stability at 1000 mA cm^-2 for 1000 h with a very low degradation rate of 3.96 µV h^-1.