Ultrafast fabrication of porous transition metal foams for efficient electrocatalytic water splitting

Developing a facile strategy for universal synthesis of transition metal catalysts is significant to catalytic reactions but remains challenging. Herein, we report an ultrafast one-step electrodeposition method to prepare a series of transition metal foams within one minute for electrocatalytic water splitting. The porous metal foams not only possess unique 3D channels for rapid electrolyte diffusion and gas releasing, but also have robust integrated structures with enhanced conductivity for efficient charge transport. Consequently, the NiCo and NiFe foams only require 86 and 206 mV to output 10 mA cm−2 for hydrogen and oxygen evolution reactions (HER and OER) in 1 M KOH, respectively. Combining the two electrocatalysts, we have assembled an outstanding alkaline electrolyzer, requiring only 1.52 and 1.64 V to deliver 10 and 100 mA cm−2 respectively, outperforming the RuO2(+)//Pt/C(-) electrolyzer. Our study offers an ultrafast and general approach to fabricate 3D porous electrocatalysts for high-performance water splitting.