Co doping of worm–like Cu2S: An efficient and durable heterogeneous electrocatalyst for alkaline water oxidation

Abstract Highly efficient water oxidation electrocatalyst plays an important role in many renewable oxygen–based electrochemical technologies like fuel cells, metal–air batteries, and water splitting devices. In this communication, we report the in–situ hydrothermal sulfidization preparation of a Co doped worm–like Cu 2 S directly grown on copper foam (Co–Cu 2 S/CF) and further application as an efficient and stable electrocatalyst for alkaline water oxidation. In 1.0 M KOH, it needs overpotentials as low as 298 and 357 mV to afford 20 and 50 mA cm −2 , respectively, comparing favourably to pure Cu 2 S counterpart (Cu 2 S/CF) and most Cu based catalysts in alkaline media. Notably, it is also durable with high turnover frequency values of 0.137 and 0.473 mol O 2 s −1 at overpotentials of 400 and 500 mV, respectively.