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

Abstract

Summary 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.

Nickel-Based Selenides with a Fractal Structure as an Excellent Bifunctional Electrocatalyst for Water Splitting

“…In this sense, the fractalstructured nanomaterials can show more unique properties than the materials with ordered surfaces. For instance, the enhanced localized field on the tips of fractal Au nanoneedles can gather ions to make a localized high-ion concertation, and thus accelerates catalytic activity [28][29][30]. Combining the enhanced field on the tip and abundant characteristics, the fractal structure shows ultra-high HER and OER activity during water splitting [31,32].…”