Effective surface roughening of three-dimensional copper foam via sulfurization treatment as a bifunctional electrocatalyst for water splitting

Cost effective electrocatalysts in water splitting reaction are critically important for the practical application of hydrogen fuel. The surface of three-dimensional copper foam is successfully roughened via one-step sulfurization reaction, and cuprous sulfide is formed on copper foam accordingly, which is denoted as Cu2S@Cu. The as-prepared Cu2S@Cu electrocatalyst exhibits remarkable performance on oxygen evolution reaction in basic solution, with a low overpotential of 345 mV to achieve 20 mA cm(-2). Cu2S@Cu also shows enhanced performance on hydrogen production, compared to the original copper foam. Furthermore, Cu2S@Cu can work as both cathode and anode in full water splitting, with superior activity to the noble metal-based electrocatalysts under large current densities. This study demonstrates that surface roughening technique on copper foam by sulfurization reaction can be valuable for developing novel copper-based electrocatalysts for water splitting. (C) 2018 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.