Facile one-pot synthesis of 2D vanadium-doped NiCl(OH) nanoplates assembled by 3D nanosheet arrays on Ni foam for supercapacitor application

摘要

Herein, the 2D NiCl(OH) nanosheets and 2D V-doped NiCl(OH) nanoplates assembled by 3D nanosheet arrays supported on nickel foam have been successfully synthesized by a facile one-pot hydrothermal reaction. The dependences of the microstructure and electrochemical performance on hydrothermal reaction time and reactant concentration were investigated, and the electrochemical performance was optimized at 12 h and C-Ni(2+) = 0.15 mM. A series of characterization results reveal that the as-prepared V-doped NiCl(OH) nanoplate arrays are successfully grown on nickel foam, and these nanoplates are composed of interconnected ultrathin nanosheets. The thickness of the as-obtained nanosheets increases with increasing reaction time, and the thickness of the optimized nanosheets is about similar to 20 nm. Vanadium dopant is used as the template agent to alter the morphology of NiCl(OH) nanosheet arrays and form the V-doped NiCl(OH) nanoplate arrays, then leading to a higher specific surface area and lower charge transfer resistance. The cost-effective, binder-free and optimized V-doped NiCl(OH) delivers the high specific capacitances of 2753.3 and 1470.0 F g(-1) at the current densities of 1 and 30 mA cm(-2), respectively. Meanwhile, an asymmetric supercapacitor is constructed with the optimized Vdoped NiCl(OH) sample as the positive electrode and activated carbon as the negative electrode. The fabricated device can exhibit a high energy densities of 45.5 W h kg(-1) at the power density of 799.5 W kg(-1) in the voltage window of 0-1.6 V. The efficient electrochemical performance of 3D V-doped NiCl(OH) nanoplate arrays makes it a favorable candidate for supercapacitor electrode material.