Simultaneous synthesis of UiO-66/ZrO2 composites for high-performance supercapacitors: Fabrication, characterization, and electrochemical evaluation

Four novel UiO-66/ZrO2 composites were successfully synthesized using microwave-assisted heating at varying temperatures. Comprehensively characterizing the composites involved the utilization of several standard analytical techniques. X-ray diffraction analysis revealed a high degree of crystallinity in the composites. The morphological examination showcased a certain level of porosity, with the composites exhibiting a maximum surface area of 330.74 m2 g−1. These UiO-66/ZrO2 composites were investigated as electrode materials for supercapacitors, with the UiO-66/ZrO2–120 composite displaying exceptional electrochemical performance. It achieved the highest specific capacitance of 913.8 F g−1 (548.3 C g−1) at a current density of 1 A g−1, surpassing the other composites. Moreover, the UiO-66/ZrO2–120 composite exhibited excellent stability, retaining 86 % of its capacitance after 3000 cycles. Additionally, we assembled a hybrid device by combining the UiO-66/ZrO2–120 composite as the positive electrode and activated carbon as the negative electrode. This configuration achieved a high specific energy of 31.2 Wh kg−1 and a specific power of 922.9 W kg−1. Remarkably, even after 5000 cycles, the hybrid device retained 81.5 % of its specific capacitance. These results underscore the outstanding performance and stability of the UiO-66/ZrO2–120//AC device.