Phosphorization engineering ameliorated electrocatalytic activity for overall water splitting on Ni3S2 nanosheets
Phosphorization engineering is an alternative method to explore high-efficiency electrocatalysts for water splitting. Herein, we present a heterostructure consisting of Ni2P and Ni3S2 supported on commercial nickel foam (Ni3S2-Ni2P/NF) through converting partial Ni3S2 into Ni2P in terms of phosphorization engineering. Electrochemical tests reveal that partial phosphorization of Ni3S2 effectively enhances the catalytic activities toward oxygen evolution reaction (OER) and hydrogen evolution reaction (HER) in 1 M KOH. In particular, the Ni3S2-Ni2P/NF electrode drives a current density of 50 mA cm-2 at a very low OER overpotential of 287 mV, and takes a low overpotential of 130 mV to afford 10 mA cm-2 for HER. Moreover, the alkaline electrolyzer assembled by two Ni3S2-Ni2P/NF electrodes can deliver 10 mA cm-2 at low voltage of 1.58 V, accompanying with excellent durability during the electrolysis of 15 h. Therefore, our work opens up an attractive fabrication strategy of highly active heterostructure electrocatalysts.