Lavender-like NiV-LDH@P,Se-doped VNi-MOF heterostructure as high-performance electrode material for supercapacitor

Core-shell heterostructure is one of the effective methods for developing electrode materials that possess high electrical conductivity and outstanding stability. In this study, VNi-MOF nanorod arrays are initially synthesized on nickel foam (NF) via a solvothermal method. Then, highly electrical conductive P,Se-doped VNi-MOF is obtained by annealing treatment in phosphorus and selenium source environment. Finally, highly specific capacity NiV-LDH nanosheet arrays are grown on the P,Se-doped VNi-MOF nanorod arrays via a hydrothermal method to construct the core-shell heterostructure (NiV-LDH@P,Se-doped VNi-MOF). Experimental analysis and density functional theory (DFT) calculations demonstrate that co-doping with P and Se, and core-shell heterostructure can notably enhance the conductivity and stability of VNi-MOF, increase its ability to capture OH⁻ ions and promote the rapid progress of redox reactions. Therefore, the electrode achieves a high specific capacity (2083.7 C g⁻¹ at 1 A g⁻¹), along with remarkable cycling stability (90% of its capacity after 10, 000 cycles). The hybrid supercapacitor (HSC) composed of NiV-LDH@P,Se-doped VNi-MOF and AC/NF displays an outstanding energy density (110.6 Wh kg⁻¹ at 866.8 W Kg⁻¹) and excellent capacity retention (91.5% after 10, 000 cycles). These findings highlight NiV-LDH@P,Se-doped VNi-MOF electrode material as a promising candidate for next-generation supercapacitors.