Multi-interfacial engineering of IrOx clusters coupled porous zinc Phosphide-Zinc phosphate heterostructure for efficient water splitting

[Display omitted] •A heterostructured catalyst of Ir (3.85 wt%)-based clusters/Zn3P2-ZnPi is prepared.•The catalyst effectively enhances the HER and OER activities in alkaline medium.•The electrolyzer needs a cell voltage of 1.62 V at 10 mA cm−2 for water splitting.•The electrolyzer has better activities and stability than Pt/C(-)//RuO2(+) system. Herein, a heterostructured electrocatalyst derived from ultrasmall iridium (3.85 wt%)-based clusters (IrOx) integrated zinc phosphide (Zn3P2)-zinc phosphate (ZnPi) nanosheets (NSs) is rationally fabricated by a facile approach. The IrOx/Zn3P2-ZnPi NSs catalyst possesses efficient catalytic activities and prospective stability due to its large electroactive surface area, excellent charge transfer, high mechanical properties of the structure, and good catalyst-substrate interactions. As a result, the IrOx/Zn3P2-ZnPi NSs catalyst exhibits an overpotential of 106 mV for hydrogen evolution reaction (HER) and 286 mV for oxygen evolution reaction (OER) to reach a current output of 10 mA cm−2 in 1.0 M KOH medium, which are significantly lower than those of the IrOx/Zn3P2-ZnPi nanorods (NRs) and previously reported bifunctional electrocatalysts. An electrolyzer derived from the IrOx/Zn3P2-ZnPi NSs(+,-) requires a small cell voltage of 1.62 V at 10 mA cm−2 and 1.84 V at 100 mA cm−2, surpassing behaviors of a commercial Pt/C(-)//IrO2(+) system. The results indicate that the IrOx/Zn3P2-ZnPi NSs is a potential bifunctional electrocatalyst for efficient water splitting application to produce green hydrogen fuel.