Waste polyethylene terephthalate plastic derived Zr-MOF for high performance supercapacitor applications

The chemical conversion of plastic waste into metal-organic framework (MOF) materials has emerged as a significant research field in addressing issues associated to the environment and the economy. The significant advantages of MOFs as electrode material for energy/supercapacitors arises from their extensive surface area and notable porosity. The present study involved the synthesis of Zirconium-Metal Organic Frameworks (Zr-MOF) by the solvothermal method, utilizing plastic waste in the form of Polyethylene terephthalate (PET) bottles. The morphological and structural characteristics of the Zr-MOF were inspected through several analytical techniques, including scanning electron microscopy, transmission electron microscopy, X-ray diffraction, and Fourier-transform infrared spectroscopy analysis. The as prepared Zr-MOF demonstrated very high specific surface area of 927.567 m² g^-1 with mesoporous nature of the materials estimate by BJH method. The electrochemical characteristics of the Zr-MOF in 3-electrode system exhibited a notable specific capacitance of 822 F g^-1 when subjected to a low scan rate of 2 mV S^-1, while the specific capacitance estimated through galvanostatic charge-discharge exhibited an enhanced value of 890 F g^-1 at a current density of 0.5 A g^-1. Additionally, the working electrode composed of Zr-MOF demonstrated noteworthy capacitance retention of 92% after 5000 charge discharge cycles. This research presents novel opportunities for the utilization of waste PET bottles in fabrication of highly functional Zr-MOF, aiming to advance the development of next-generation supercapacitors and environmental remediation.