Cu-MOF-derived CuO/NiO/Ni3(VO4)2 composite materials with improved electrochemical performance for supercapacitor

In the present study, after the synthesis of Cu-based metal–organic framework (MOF), to take its advantage in electrode active material of a supercapacitor, Nickel and Vanadium were added to the synthesized MOF through post-synthetic procedures and after calcination at a temperature of 500 °C, two composites of CuO/NiO, and CuO/NiO/Ni 3 (VO 4 ) 2 were achieved to study the effect of Nickel Vanadate on the supercapacitive performance of the CuO/NiO composite. The synthesized active materials were characterized with powder X-ray diffraction analysis, Fourier-transform infrared spectroscopy, field-emission scanning electron microscopy, as well as surface area and porosity analyzer. Moreover, to observe the effect of various electrolytes on the electrochemical performance of each composite the cyclic voltammetry and galvanostatic charge–discharge studies were performed in four different environments of Na 2 SO 4 (1 M), NaOH (3 M), KOH (3 M), and LiOH (3 M). The results of CV and GCD tests revealed the pseudocapacitive behavior of the fabricated active material, in which the CuO/NiO/Ni 3 (VO 4 ) 2 electrode yielded the maximum storage capacity at a gravimetric current of 2 A/g with the amount of 37.04 C/g in LiOH (3 M) electrolyte. Moreover, Dunn's calculation revealed that both surface- and diffusion-dominated processes contributed differently to the electrode's overall capacity for charge storage in all electrolytes.