Monolithic NixMy (M = OH, P, S, Se) nanosheets as efficient and stable electrocatalysts for overall water splitting

Development of high-performance electrocatalysts for overall water splitting is vital for the production of renewable hydrogen energy. Monolithic Ni(OH)(2) nanosheets are fabricated through a facile hydrothermal oxidation procedure of commercial Ni foam. And Ni2P, Ni2S3 and NiSe2 nanosheets are obtained by subsequent low-temperature phosphorization, sulfurization and selenization of the monolithic Ni(OH)(2) nanosheets, respectively. The resultant monolithic materials can be directly employed as self-supported electrodes for efficient oxygen evolution reaction (OER) and hydrogen evolution reaction (HER) in alkaline media, especially, Ni(OH)(2) nanosheets for OER and Ni2P nanosheets for HER, respectively, revealing their versatile and practical nature for hydrogen production. Moreover, a well water electrolyzer through a matched electrode pair with Ni(OH)(2) nanosheets as anode and Ni2P nanosheets as cathode can achieve a water splitting current density of 10 mA cm(-2) at a cell voltage of 1.64 V, and maintains this current density as least 48 h without evident decay in 1.0 mol L-1 KOH electrolyte. These efficient electrocatalysts with a low-cost, facile synthesis procedure and additive-free properties have great potential for emerging realistic energy storage and conversion fields. (C) 2018 Elsevier Ltd. All rights reserved.