Construction of NiSe2/Ni3B2O6 heterostructures on electrospun carbon nanofibers for high-performance supercapacitor and hydrogen evolution reaction

A crystalline NiSe 2 /amorphous Ni 3 B 2 O 6 heterojunction on electrospun carbon nanofibers was constructed. • CCo@NiSe@NiBO as supercapacitor electrode materials exhibited a specific capacitance of 984.0 F g −1 . • CCo@NiSe@NiBO as a HER catalyst achieved overpotentials of 227 mV at 10 mA cm −2 and Tafel slopes of 91.2 mV dec −1 . • NiSe 2 /Ni 3 B 2 O 6 heterojunction with favorable electronic distribution led to the optimized adsorption energy. • CCo@NiSe@NiBO//AC device displayed an energy density of 35.58 Wh kg −1 and excellent cycling stability. Heterostructured engineering is driving advancements in supercapacitor and hydrogen evolution reaction (HER). In this work, a NiSe 2 /Ni 3 B 2 O 6 heterostructure on electrospun carbon nanofibers was fabricated as a dual-functional material. The NiSe 2 /Ni 3 B 2 O 6 heterojunction with favorable electronic distribution and the well-dispersed active sites supported by electrospun carbon nanofibers, facilitate conductivity, stability and reaction kinetics. CCo@NiSe@NiBO, belonging to an energy storage mechanism dominated by diffusion control, showed a specific capacitance of 984.0 F g −1 , and a capacitance retention of 42.68 % when the current density increases by 20 times, which exceeds that of many reported Ni based selenides and borides. Meanwhile, CCo@NiSe@NiBO as a HER catalyst achieved overpotentials of 227 mV at 10 mA cm −2 and Tafel slopes of 91.2 mV dec −1 . DFT calculations revealed its optimized adsorption energy of OH − for CCo@NiSe@NiBO. In addition, a CCo@NiSe@NiBO//active carbon hybrid device displayed an energy density of 35.58 Wh kg −1 as well as 91.88 % of its initial capacitance after 10,000 cycles. It was successfully integrated into the circuit. This work emphasizes the advantages of electrospun nanofibers in constructing heterostructures and establishes heterostructured engineering as a powerful strategy for advancing energy storage devices and catalysis. A NiSe 2 /Ni 3 B 2 O 6 heterojunction on carbon nanofiber with electronic modulation was fabricated for supercapacitor and hydrogen evolution reaction. Download: Download high-res image (328KB) Download: Download full-size image