Sustainable Nanoporous Metal–Organic Framework/Conducting\nPolymer Composites for Supercapacitor Applications

Abstract

An economically and environmentally\nsustainable course of action\nto address energy crisis concerns is to recycle discarded PET (polyethylene\nterephthalate) plastics into value-added products for the aforementioned\napplication. Herein, a high surface area Cu-metal organic framework\n(Cu-MOF) has been synthesized through an economically feasible approach\nusing trash PET plastic. However, electrochemical properties of pristine\nMOFs are hindered due to their poor stability and low intrinsic conductivity.\nHence, high-performance nanocomposites of Cu-MOF with conducting polymers\nlike PANI (polyaniline) and PPy (polypyrrole) have been synthesized\nvia an <i>in situ</i> hydrothermal technique. PANI and PPy\nnot only improve the conductivity of the nanocomposite but also create\nadditional MOF-PANI-MOF transport channels, which ensures effective\nelectrolyte ion transportation and hence enhances the overall electrochemical\nperformance. Cu-MOF/PANI and Cu-MOF/PPy nanocomposites exhibit high\nspecific capacitances of 160.5 and 132.5 F/g, respectively, at a\ncurrent density of 0.5 A/g, which is more than that of pristine Cu-MOF\n(104.8 F/g). Furthermore, asymmetric hybrid supercapacitor devices\n(Cu-MOF//Cu-MOF/PANI and Cu-MOF//Cu-MOF/PPy) have been assembled that\nhave shown immense potential as energy storage devices. The Cu-MOF//Cu-MOF/PANI\nhybrid device delivered a high energy density of 51.4 Wh/kg at 474\nW/kg power density with outstanding cyclic stability, attenuating\nonly 6.6% after 10 000 charge–discharge cycles.