Controllable constructing alloy dendrites with fractal structure as free‐standing electrode for enhanced oxygen evolution

The design of non–noble metal binderless electrode for enhanced electrocatalytic oxygen evolution is an unremitting challenge. Herein, we first report the construction of fractal structural alloy electrodes using controllable electrodeposition. Meanwhile, we have explored the regulation and morphology transition of metal dendrites in the electrolytic process. The metal wire-type "one-body" electrode prepared in the full-immersion reactor demonstrates the unique three-dimensional fractal structure with high branching degree and surface area. Moreover, the compositional turning of metal crystal via element doping is beneficial to improving the conductivity and crystal structure. The Ni and Zn elements are introduced to form Ni-Fe and Zn-Fe alloy dendrites, showing a preferable electrochemical catalytic oxygen evolution performance. The as-prepared Ni-Fe dendrite demonstrates a lower overpotential about 248 mV (vs RHE) at 10 mA cm−2 and Tafel slope of 55 mV dec−1 in the alkaline condition.