Preparation and electrocatalytic oxygen evolution performance of CoWO₄/NC composites

Transition metal-based electrocatalysts with abundant reserves and low cost have been widely studied as potential substitutes for efficient oxygen evolution reaction (OER) precious metal electrocatalysts, but there are still problems of poor activity and conductivity. Here, a Co-MOF (ZIF-67) as precursor was designed to prepare a nitrogen-doped carbon (NC) based CoWO₄ (CoWO₄/NC) catalyst was reported with abundant oxygen vacancy through pyrolysis after adoption Tungsten chloride (WCl₆). The feeding ratio and calcination temperature of the catalyst were explored. OER performance in alkaline medium was tested. The test results showed that the catalyst prepared at a feeding ratio of 1∶1 and a calcination temperature of 550℃ exhibited a lower overpotential (346 mV, J=10 mA·cm⁻²), a lower Tafel slope (65 mV·dec⁻¹) and a higher conductivity. The stability of the catalyst under alkaline conditions was tested by the timing potential method. The performance did not degrade significantly within 22 hours. This work provides a new idea for the research of transition metal-based catalyst and has certain guiding significance for the design of catalyst.