Interface engineering of NiO/RuO2 heterojunction nano-sheets for robust overall water splitting at large current density

Abstract

NiO/RuO 2 heterojunction nano-sheets in situ grown on nickel foam can steadily work for 72h towards overall water splitting in industrial condition (1500 mA cm −2 , 6.0 M KOH electrolyte, 60 ℃). • Interface coupling effect could tune electronic structure to boost water splitting. • NiO/RuO 2 /NF can work stably in industrial condition for 72 h. • Only 1.44 V is needed to get 10 mA cm −2 for overall water splitting. It is of great potential to develop efficient and robust Ru based bifunctional catalysts for water electrolysis. In this work, NiO/RuO 2 heterojunction nano-sheets in situ grown on nickel foam (NiO/RuO 2 /NF) is successfully prepared, which shows good activity and stability for both oxygen and hydrogen evolution reaction (OER and HER). For overall water splitting (OWS), it only needs 1.44 V to obtain 10 mA cm −2 in 1.0 M KOH solution. Notably, it can work for 72 h at ± 1,500 mA cm −2 toward OER, HER and OWS with small activity decrease. Under simulated industrial conditions, 1.90 V is needed to drive 1,500 mA cm −2 , and it also can work steadily for 72 h. The reason could be attributed to the heterogeneous interface coupling effect and nano-sheets with rough surface directly grown on NF. Hence, this work provides a feasible strategy for developing robust bifunctional Ru based water splitting catalysts.