Nanoporous nickel-selenide as high-active bifunctional electrocatalyst for oxygen evolution and hydrazine oxidation

Abstract Designing efficient oxygen evolution reaction (OER) catalyst or employing hydrazine oxidation (HzOR) to replace OER are two promising approaches to reduce the water electrolysis overpotential for hydrogen production. In this work, NiSe-1, NiSe-2 and NiSe-3 were electrodeposited from the baths with different ratios of NiCl2·6H2O and SeO2 (2:1, 1:1 and 1:2) on nickel foam (NFs) as bifunctional electrocatalyst for HzOR and OER. respectively. In comparison with NiSe-1 and NiSe-3, NiSe-2 with nanoporous structure exhibits superior catalytic performance towards OER with a low overpotential of 252 mV vs. RHE to achieve 10 mA cm−2 and a high durability (16 h at 100 mA cm−2). NiSe-2 further shows excellent performance towards HzOR with an enomous current density of 318 mA cm−2 at 0.4 V vs. RHE and a high stability (24 h at 100 mA cm−2). A special mechanism was suggested and demonstrated for remarkably enhanced catalytic performance of bifunctional NiSe-2 electrocatalyst. This can be associated with its high conductivity, uniformly distributed nanoporous structure, large electrochemically surface area and more importance of the superaerophobic surface caused by nanoporous structure of NiSe-2. The as-prepared bifunctional Ni-based selenide catalyst suggests its potential use for HzOR and OER during water electrolysis.