Abstract
Currently, there is a great environmental and economic need to convert polyethylene terephthalate bottles into high-value metal-organic framework materials. Metal-organic frameworks demonstrate great dominance over other materials owing to high surface area and exceptional porosities. Herein, a simple chemical approach was employed to produce metal-oxide nanoparticles (ZnO and Co3O4) embedded mesoporous carbon (ZnO@MC and Co3O4@MC composites) via carbonization of polyethylene terephthalate bottles derived metal-organic frameworks for supercapacitor application. Very high specific surface areas of ∼2183 and ∼2503 m2g−1were achieved of ZnO@MC and Co3O4@MC composites for the first time. The mesoporous nature of ZnO@MC and Co3O4@MC composites was confirmed through BJH (32 Å and 42 Å) and DA (38 Å and 39 Å) pore size studies. The specific capacitances of ZnO@MC and Co3O4@MC composites were estimated to ∼97 and ∼180 F/g, respectively, at 5 mV/s using 6 M KOH in a two-electrode system from cyclic voltammetry analysis. The energy density of 68 Wh/kg at a power density of 149.1 W/kg was estimated for the Co3O4@MC composite. The galvanostatic charge discharge showed an excellent stability for Co3O4@MC composite (∼5.20% loss after 5000 segments). The Co3O4@MC composite demonstrated extraordinary supercapacitor performance because Co3O4 having good Faradaic process and high theoretical capacitance. The symmetric supercapacitive performance of Co3O4@MC composite show good capacitance, stability and rate capability.
[Display omitted]
•Highly porous composites were fabricated using waste PET bottles.•The utilization of PET bottles takes a new route in solid waste management.•Electrochemical properties of composites were studied in two electrode system.•ZnO@MC and Co3O4@MC showed high specific surface area of ∼2183 and ∼2503 m2 g−1•Supercapacitor electrodes with high specific energy & specific power were developed.