Corrosive-coordinate engineering to construct 2D-3D nanostructure with trace Pt as efficient bifunctional electrocatalyst for overall water splitting

The development of efficient electrocatalysts for hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) with excellent catalytic performance and stability plays key roles in the commercialization of water splitting to generate hydrogen energy. Herein, a 2D-3D nanostructure composed of metal hydroxides and Prussian blue analogus (PBA) was in-situ decorated onto the NiFe foam (Pt-NiFe PBA) through a facile and scalable corrosive-coordinate approach. The specifically designed morphology favored the provision of abundant active sites, optimized the reaction pathway, and accelerated mass transport during the electrocatalytic process. Consequently, the as-synthesized Pt-NiFe PBA reached 10 mA cm−2 with small overpotentials of 29 and 210 mV in 1 mol L−1 KOH deionized water for HER and OER, respectively. Remarkably, Pt-NiFe PBA required an overpotential of 21 mV to drive 10 mA cm−2 in seawater containing 1 mol L−1 KOH with prominent durability. Moreover, with the as-synthesized Pt-NiFe PBA as bifunctional electrocatalyst, the Pt-NiFe PBA∥Pt-NiFe PBA electrolyzer needed 1.46 and 1.48 V to drive 10 mA cm−2 in 1 mol L−1 KOH with deionized water and 1 mol L−1 KOH with seawater, respectively. Remarkably, sustainable energies were utilized to power the overall water splitting and stored as easily portable hydrogen energy.