BiCo-MOF@NiO/PANI/rGO composite electrode with enhanced conductivity and stability for hybrid supercapacitor and HER applications

A novel electrode material, BiCo-MOF@NiO/PANI/rGO, was prepared through a low-cost hydrothermal method. The crystallinity and surface morphology were analyzed using XRD and SEM, and the BET study confirmed a specific surface area of 314 m 2 /g. Electrochemical testing showed that BiCo-MOF@NiO/PANI/rGO (B2) delivered a high specific capacity (Qs) of 431.66 mAh g −1 at 1.5 A g −1 , which is significantly greater than that of BiCo-MOF@NiO (100.08 mAh g −1 ) and BiCo-MOF@NiO/PANI (242.95 mAh g −1 ). Under a two-electrode asymmetric configuration, the device attained a Qₛ of 132.37 F/g at 0.7 A/g and maintained 83.3 % capacity after 10,000 cycles. It also offered a high energy density of 81.2 Wh kg −1 and a power density of 2695.7 W kg −1 . In addition to energy storage capabilities, the material exhibited notable electrocatalytic behavior for the HER, with a low Tafel slope (Ts) of 47.62 mV dec −1 . The outcomes highlight the composite's potential as a multifunctional material for both energy storage and electrocatalysis, paving the way for next-generation sustainable technologies.