A Superaerophobic Bimetallic Selenides Heterostructure for Efficient Industrial-Level Oxygen Evolution at Ultra-High Current Densities

Cost-effective and stable electrocatalysts with ultra-high current densities for electrochemical oxygen evolution reaction (OER) are critical to the energy crisis and environmental pollution. Herein, we report a superaerophobic three dimensional (3D) heterostructured nanowrinkles of bimetallic selenides consisting of crystalline NiSe(2) and NiFe(2)Se(4) grown on NiFe alloy (NiSe(2)/NiFe(2)Se(4)@NiFe) prepared by a thermal selenization procedure. In this unique 3D heterostructure, numerous nanowrinkles of NiSe(2)/NiFe(2)Se(4) hybrid with a thickness of ~ 100 nm are grown on NiFe alloy in a uniform manner. Profiting by the large active surface area and high electronic conductivity, the superaerophobic NiSe(2)/NiFe(2)Se(4)@NiFe heterostructure exhibits excellent electrocatalytic activity and durability towards OER in alkaline media, outputting the low potentials of 1.53 and 1.54 V to achieve ultra-high current densities of 500 and 1000 mA cm(−2), respectively, which is among the most active Ni/Fe-based selenides, and even superior to the benchmark Ir/C catalyst. The in-situ derived FeOOH and NiOOH species from NiSe(2)/NiFe(2)Se(4)@NiFe are deemed to be efficient active sites for OER. [Image: see text] ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (10.1007/s40820-020-00442-0) contains supplementary material, which is available to authorized users.