Branch-leaf-shaped CuNi@NiFeCu nanodendrites as highly efficient electrocatalysts for overall water splitting

Engineering structural and electronic properties of electrocatalysts is a direct method to boost water splitting. Herein, distinctive branch-leaf-shaped CuNi@NiFeCu nanodendrites are successfully synthesized by a novel bionic design strategy. Importantly, this unique catalyst can display superior performance for overall water splitting, which only requires 42 mV at 10 mA cm −2 for hydrogen evolution reaction (HER) and 285 mV at 50 mA cm −2 for oxygen evolution reaction (OER). Further mechanism studies disclosed that Cu atoms in nanosheet edges not only act as key active sites for HER, but also draw electron in e g orbital of Fe active sites, which weakens the adsorption strength of oxygen-intermediate and accordingly enhances OER activity. Moreover, the optimized structure can prevent the agglomeration of nanosheets, provide numerous crystalline-amorphous interfaces and oxygen vacancies, which is beneficial to the enhancement of reaction kinetics. This work paved an original strategy to improve the activity of 2D materials.