Superaerophobic Ni3N/Ni@W2N3 multi-heterointerfacial nanoarrays for efficient alkaline electrocatalytic hydrogen evolution reaction

The hydrogen evolution performances of electrocatalysts are greatly restricted by their unfavorable hydrogen evolution kinetics and the undesirable accumulation of as-evolved gas bubbles on the electrocatalysts surface. Herein, we present the fabrication of self-supporting multi-heterointerfacial nanoarrays electrode toward addressing these challenges simultaneously. A monolith Ni3N/Ni@W2N3 electrode is prepared, which exhibits a multi-heterojunction interface between the different components. The construction of this multi-heterojunction interface allows for the redistribution of the electrons, thus alleviating the strong Ni-H bond and optimizing the hydrogen adsorption free energy toward more efficient HER catalysis. Moreover, by virtue of the distinct nanoarray structure, the Ni3N/Ni@W2N3 nanoarrays exhibit improved hydrophilicity and superaerophobicity compared with Ni/Ni3N, facilitating water contact and enabling more efficient detachment of the as-evolved H-2 bubbles from the surface. Benefiting from these attractive features, the Ni3N/Ni@W2N3 nanoarrays deliver an attractive alkaline HER catalytic activity with a low overpotential of 66 mV to achieve a current density of 10 mA cm(-2), which is comparable with that of the benchmark Pt/C electrode. Moreover, the electrode exhibits remarkable stability during long-term electrolysis. The simultaneous interface and nanostructure engineering provide a feasible pathway for obtaining high-performance electrodes and beyond for various electrochemical reactions.