Constructing urchin-like Ni3S2@Ni3B on Ni plate as a highly efficient bifunctional electrocatalyst for water splitting reaction.

Developing efficient and promising non-noble catalysts that can promote both the HER and OER in the same electrolyte is vital. Currently, these reported bifunctional catalysts show only moderate electrocatalytic water-splitting performance, which is much lower than expected. In addition, most of these promising nonprecious electrocatalysts work well only at small current densities (e.g. 10 mA cm-1), but at large current densities their stability and activity are far from satisfactory for practical applications. Herein, we have successfully constructed an urchin-like Ni3S2@Ni3B heterostructure electrocatalyst on Ni plates. The resulting material exhibits great catalytic activities for both the HER and OER, even at large current densities, reaching a current density of 1000 mA cm-l at relatively low applied overpotentials of 517 and 632 mV, respectively. The excellent catalytic performance of Ni3S2@Ni3B/NP is found to benefit from the effective integration of the unique surface structure and the interface electronic structure.