Superhydrophilic Al-Doped NiP2 Nanosheets as Efficient Electrocatalysts for Hydrogen Evolution Reaction

The surface wettability of an electrocatalyst plays an important role in electrocatalysis of the hydrogen evolution reaction from water splitting. Herein, Al-doped NiP 2 nanosheets are synthesized on carbon fiber paper (Al–NiP 2 NSs/CFP) with a superhydrophilic and aerophobic surface as a hydrogen evolution reaction electrode. The Al–NiP 2 NSs/CFP electrode exhibits superior hydrogen evolution activity with a low overpotential of 58 mV to achieve 10 mA cm −2 in 0.5 m H 2 SO 4 . In particular, it even exhibits better electrochemical performance than commercial Pt/C electrodes at high current densities. Theoretical calculations indicate that Al dopants can alter the electronic structures and optimize the hydrogen adsorption free energy of NiP 2 . The superhydrophilic and aerophobic surface favors the H 2 bubbles release from the electrocatalyst surface and promotes the hydrogen evolution reaction (HER) performance at high current densities. Potential ways to fabricate efficient non-noble metal electrocatalyts for large-scale industrial hydrogen production applications are provided through electronic structure engineering and surface constructing.