Cobalt phosphate-benzene-1,3,5-tricarboxylic acid metal–organic framework @ reduced graphene oxide electrodes for hybrid supercapacitors

Novel benzene-1,3,5-tricarboxylic acid-cobalt phosphate metal–organic framework (MOFCoP@rGOx, x = 1, 2, 3, 4) hybrid electrodes are synthesized via microwave route. The as-obtained MOFCoP@rGOx composites have been subjected to physico-chemical (XRD, Raman, SEM, and BET) and electrochemical (CV, GCD, and EIS) studies. Amongst, 50 mg reduced graphene oxide (rGO)-dispersed MOFCoP@rGO2 exhibits 3D architecture in SEM and synergistically improvises faradaic and non-faradaic reactions which enhanced specific capacitances and cyclability. The XRD reveals the monoclinic crystalline geometry. The I_D/I_G ratio of Raman analysis reveals carbon coordination, and the BET analysis shows enhanced specific surface area and increase in pore voids which are accommodating more number of ions for improved electrochemical performance. XPS studies identify inherent oxidation states and chemical constituents of MOFCoP@rGO2. The CV studies on all composites are compared @ 5 mV s⁻¹, and the GCD @ 1 A g⁻¹ shows higher specific capacitance only for 50 mg doped MOFCoP exhibiting EDLC and pseudocapacitance, and the same electrode in device performance with rGO registers 133 F g⁻¹ @ 1 A g⁻¹. The equivalent series resistance is lower (0.09 Ω cm⁻²) for MOFCoP@rGO2 which results increase in conductivity and comprehends this composite for hybrid supercapacitor applications.