Assembly of NiFe-PBA nanoparticles on nanoflower-like NiFe-PBA@IF as enhanced oxygen evolution electrocatalyst at room temperature

•Nickel-iron Prussian blue is assembled by etching on foam iron at room temperature.•Oxygen evolutionary motion of NiFe Prussian Blue is monitored using XPS, SEM and XRD.•NiFe-PBA@IF surface etching with embedded NiFe Prussian blue particles can improve the roughness.•At a current density of 10 mA • cm−2, the NiFe-PBA@IF overpotential is 253 mV with perfect stability.•NiFe-PBA@IF provides an idea for the synthesis of electrocatalysts at room temperature. Oxygen Evolution Reaction (OER) catalysts that overcome low energy barriers to improve the reaction efficiency of the OER are important for the development of future green energy sources. Herein, NiFe-PBA@IF layered nanoflowers were successfully prepared by etching iron foam (IF) using Prussian blue-like (PBA) material as a precursor. Notably, the fractured PBA nanosheets prepared by etching at room temperature had a suitable growth gradient and growth environment with the homogeneous nucleation environment, compared to the conventional method. In this environment, a layered NiFe-PBA structure can be formed on the surface of IF, enabling efficient green synthesis, reducing ecological and economic costs, and providing a clear source of catalytic activity. More importantly, NiFe-PBA@IF has a nanoparticle structure anchored on NiFe-PBA stacked nanoflowers, which can expand the surface roughness and electrochemical active area of the sample, so the OER performance in 1 M KOH is 253 mV@10 mA·cm−2. The green and direct synthesis of PBA electrocatalysts can provide new ideas for the efficient synthesis of other OER electrocatalysts at room temperature and will further provide an effective template for the industrial application of OER electrocatalysts. We propose to assemble NiFe-PBA small particles on NiFe-PBA@IF to improve the mass specific activity and roughness, and green etch the surface of iron foam in NiFe-PBA solution, which promotes the appearance of surface cracks, pits and bending edges, and improves the synthesis efficiency of PBA layer on the substrate. NiFe-PBA@IF uses a single material to make the active source of oxygen evolution reaction (OER) clearer. In 1.0 M KOH electrolyte, the overpotential is 253 mV at a current density of 10 mA·cm−2. In addition, by monitoring NiFe-PBA@IF, the intermediate products during OER were preliminarily analyzed, and the catalyst was stable in the electrochemical reaction. [Display omitted]