Regulating Mo-based alloy-oxide active interfaces for efficient alkaline hydrogen evolution assisted by hydrazine oxidation

Abstract

Improving the efficiency of overall water splitting (OWS) is crucial due to the slow four-electron transfer process in the oxygen evolution reaction (OER). The coupling of the thermodynamically favorable hydrazine oxidation reaction (HzOR) with the hydrogen evolution reaction (HER) significantly boosts hydrogen production. A Ru-decorated MoNi/MoO2 micropillar (Ru-MoNi/MoO2) has been synthesized using a hydrothermal followed by reduction annealing. Benefiting from Ru moderating the active interface of Mo-based alloys/oxides and the unique one-dimensional micropillar morphology. The synthesized Ru-MoNi/MoO2 exhibits outstanding bifunctional activity for HER and HzOR, achieving 10 mA cm−2 at merely −13 mV and −34 mV in 1 M KOH and 1 M KOH + 0.5 M N2H4, respectively. Notably, with Ru-MoNi/MoO2 in a dual-electrode setup, only 0.57 V is needed to achieve 50 mA cm−2, demonstrating good stability and facilitating hydrazine-assisted water splitting (OHzS). This work offers insights into the modulation of alloy/metal oxide active interfaces, contributing to the development of efficient bifunctional catalysts for HER and HzOR.