Oriented construction Cu3P and Ni2P heterojunction to boost overall water splitting

Development of efficient and earth-abundant bifunctional catalysts towards oxygen evolution reaction (OER) and hydrogen evolution reaction (HER) is imperative to overall water splitting. Herein, in-situ vertically grown bimetallic phosphide nanosheets containing abundant Cu3P/Ni2P heterogeneous interfaces are successfully synthesized on Cu foam (marked as Cu3P/Ni2[email protected]) as the bifunctional electrocatalyst for both HER and OER. Owing to the synergistic effects of electronic regulation of heterojunction and the hierarchical array structure on 3D substrate, the Cu3P/Ni2[email protected] integrated electrode displays the overpotential of 330 mV @ 50 mA cm−2 for OER and 88.1 mV @ 10 mA cm−2 for HER in 1 M KOH. Interestingly, the catalyst –based water electrolyzer only demands a low cell voltage of 1.56 [email protected] mA cm−2, exceeding the integrated Pt/C + IrO2 counterpart. Density functional theory (DFT) results further disclose that the charge rearrangement of heterogeneous interface can not only endow the hydrogen binding energy (ΔG*H) approach to zero, but also boost the H2O dissociation and *OH desorption via multi-site synergy for HER. This work provides a valuable approach to construct advanced materials towards overall water splitting.