Cobalt-doped copper vanadate: a dual active electrocatalyst propelling efficient H2 evolution and glycerol oxidation in alkaline water

Abstract

Strategically doped metal oxide nanomaterials signify a rapidly growing genre of functional materials with a wide range of practical applications. Copper vanadate (CuV) represents one such highly active system, which has been rarely explored following its doping with an abundant first-row transition metal. Here, we have developed a series of CuV samples with varying cobalt(II) doping concentrations deploying a relatively simple solid state synthetic procedure. Among the samples, the 10% Co(II)-doped CuV (Co_10%–CuV) exhibited excellent reactivity for both the H₂ evolution reaction (HER) and glycerol oxidation reaction (GOR) in an alkaline aqueous medium (pH 14.0) during cathodic and anodic scans, respectively. During this dual-active catalysis, surface-immobilized Co_10%–CuV operates at exceptionally low overpotentials of 176 mV and 160 mV for the HER and GOR, respectively, while achieving 10 mA cm² current density. The detailed spectroscopic analysis revealed the formation of formate as the major product during the GOR with a faradaic efficiency of >90%. Therefore, this Co_10%–CuV can be included on either side of a two-electrode electrolyzer assembly to trigger a complete biomass-driven H₂ production, establishing an ideal carbon-neutral energy harvest process.