Interfacial electronic modulation on heterostructured NiSe@CoFe LDH nanoarrays for enhancing oxygen evolution reaction and water splitting by facilitating the deprotonation of OH to O

Abstract

NiSe@CoFe LDH/NF heteroarrays show superior OER and overall water splitting performance owing to in-situ growth for strengthening the stability, and the heterointerfacial electronic modulation for facilitating the deprotonation of OH to O during OER process. • NiSe@CoFe LDH heteroarrays were constructed by selenization and electrodeposition. • Three-dimensional heterostructure enable more accessible active sites for OER. • Interfacial electronic modulation enable the facilitating deprotonation of OH to O. • NiSe@CoFe LDH heteroarrays exhibits superior OER and water splitting performance. Achieving low-cost and high-efficiency oxygen evolution reaction (OER) catalysts by interfacial engineering has attracted numerous attentions. Herein, the combination of selenization of Ni foam (NF) and successive electrodeposition growth of CoFe LDH was proposed to synthesize the three-dimensional heterostructure of NiSe nanowires and CoFe LDH nanosheets on NF (NiSe@CoFe LDH/NF) which can enable more accessible active sites, enhanced structural stability, and eliminate contact resistance for OER process. The optimal NiSe@CoFe LDH/NF possesses superior OER performance with ultralow overpotential of 203 and 236 mV to achieve 10 and 100 mA cm −2 , low Tafel slope of 90.3 mV dec −1 and robust stability in 1.0 M KOH electrolyte. Density functional theory (DFT) calculations unveil that the interfacial synergism on NiSe@CoFe LDH can induce electrons redistribution by charge transfer from CoFe LDH to NiSe, and reduce the energy barrier of deprotonation of OH to O as the rate-limiting step by the stronger chemical bond of Fe-O in OER, and thus significantly increase the intrinsic OER activity. Moreover, the two-electrode configuration based on NiSe@CoFe LDH/NF||Pt/C/NF couple for driving water splitting can achieve a current density of 300 mA cm −2 at an ultralow voltage of 1.69 V with super stability (100 h). This work provides deep insights into the roles of interfacial electronic modulation by fabrication the three-dimensional heterostructure to design high-efficiency electrocatalysts for OER.