The bamboo-like CoW alloy N-doped carbon catalysts for hydrogen evolution and oxygen evolution/reduction trifunctional electrocatalysts in water electrolyzer and the zinc-air battery.

Abstract

Tungsten-based intermetallic materials emerged as desirable alternatives for high-cost OER, HER, and ORR catalysts due to their improved activity and stability. An N-doped carbon nanotube containing CoW alloy was synthesized by pyrolysis of metatungstate@ZIF-67 and melamine precursor. Thus, the synthesized CoW-N/C catalyst shows the E ₁₀ values of oxygen and hydrogen evolution reactions as 1.6 V and −0.24 V vs RHE, respectively. It is analyzed for water-splitting performance and exhibits a cell potential of 1.79 V at 10 mA cm⁻², which is comparable with Pt/C and RuO₂ catalysts combination. The water electrolysis was performed using a chronopotentiometric experiment at 10 mA cm⁻² for 20 h. Besides, the catalyst shows the oxygen reduction activity with the E _onset of 0.93 V vs RHE and was analyzed for its performance in the zinc-air battery. Interestingly, the catalysts yield the maximum power density of 111.3 mW cm⁻², which is better than the benchmark catalysts (Pt/C + RuO₂). Thus, the CoW-containing N-doped carbon catalysts behave as trifunctional. This study highlights the multifunctional activity of CoW alloy catalysts across diverse electrochemical reactions, emphasizing their promising applications in energy storage devices and electrolyzers.