Zn‐Doped Porous CoNiP Nanosheet Arrays as Efficient and Stable Bifunctional Electrocatalysts for Overall Water Splitting

The design of electrocatalysts with a favorable interface for mass transfer, adsorption, and activation of reactant is important for water splitting. Herein, the design of porous Zn‐doped CoNiP arrays anchored on Ni foam (P‐Zn‐CoNiP/NF) as effective bifunctional electrocatalysts for overall water splitting is reported. The key to construct P‐Zn‐CoNiP is first the introduction of Zn species in NiCoP anchored on Ni foam (NF) followed by its selective etching in dilute HCl to leave pores and form doping in final CoNiP. The pores facilitate the mass of transfer and expose more active sites. The Zn doping can modulate the electronic structure of NiCoP. Benefited from the aforementioned characteristics, the P‐Zn‐CoNiP/NF possesses remarkable activity for oxygen evolution reaction (OER) and hydrogen evolution reaction (HER) in 1 m KOH, which can produce a current density of 100 mA cm −2 at a low overpotential of 177 and 396 mV for HER and OER, respectively, which is superior to most non‐noble metal‐based catalysts. The cell assembled using P‐Zn‐CoNiP/NF as both cathode and anode achieves a current density of 50 mA cm −2 at a voltage of 1.71 V and can be driven by a solar cell (1.51 V), indicating its potential for practical storage of solar energy.