Facile synthesis of interlaced flower-like layered double hydroxides grown on porous CoMoP as a highly efficient electrocatalyst for hydrogen evolution reaction

Rational morphology design and electronic structure modulation of efficient and durable electrocatalyst for hydrogen evolution reaction (HER) are urgent and challenging tasks to solve the large overpotential problems currently required. Herein, this study investigated the effect of dual electrodeposition and doping on the HER performance of electrocatalysts. Highly porous cobalt molybdenum phosphate (CoMoP) was used as a support for three different layered double hydroxides (LDHs)including cobalt nickel (CoNi), nickel iron (NiFe), and cobalt iron (CoFe). CoFe-LDH/CoMoP electrodeposited on nickel foam (NF) only need 22.5 mV overpotential to reach current response of 30 mA cm-2. To be used as a HER electrocatalyst, however, NiFe-LDH/CoMoP/NF (383 mV) and CoNi-LDH/CoMoP/NF (117 mV) require much higher overpotential than that of CoFe-LDH/CoMoP/NF. The newly developed porous CoFe-LDH/CoMoP/NF works well as an active HER electrocatalyst in the alkaline medium with a low overpotential. In the analysis of the second electrodeposition effect on HER performance of the three developed LDHs, the second electrodeposited CoFe-LDH/CoMoP/NF electrocatalyst showed greatly decreased Tafel slope and overpotential at a constant time as compared to the first electrodeposition. Considering their superior HER performance and keeping good stability even after 19 h, the developed electrocatalysts could be an excellent replacement for non-noble-metal HER catalysts.