Highly efficient photothermal catalytic upcycling of polyethylene terephthalate via boosted localized heating

Photothermal catalysis driven by clean solar energy efficiently converts plastic waste into high-value-added products. The catalytic process involves the transformation of solar energy to chemical energy. However, designing photothermal catalysts with a high conversion efficiency and catalytic activity remains considerably challenging. In this study, a c-ZIF-8@SiO2 nanostructure is fabricated. It acts both as the photothermal reagent and the catalyst, displaying high photothermal conversion efficiency, catalytic activity, and stability in polyethylene terephthalate (PET) glycolysis. SiO2-coated c-ZIF-8 effectively reduces the thermal radiation loss of the carbon material, thus enhancing the local thermal effect of the catalytic system. Consequently, the conversion efficiency of PET achieved using photothermal catalysis is 3.4 times higher than that of thermal catalysis under the same conditions. An economic efficiency analysis proves that photothermal catalysis can save 6390000 kW·h of electricity and reduce up to 3089.59 tons of CO2 emissions for every 10000 tons of PET recycled. Therefore, the development of clean energy-driven photothermal catalysis technology could be a potential solution for the upcycling of waste plastics.