Advanced strategies for plastic upcycling: unlocking sustainable waste valorization pathways for a green and sustainable environment

The growing demand for plastic materials in different aspects of human life has created a serious burden on the environment due to the non-degradable nature of plastic wastes. Therefore, the growing concerns over sustainability and environmental pollution have driven a huge research curiosity for the upcycling of plastic wastes to essential chemical commodities and green fuels. To date, most of the plastic wastes are being upcycled using different conventional approaches like mechanical and thermal methods, which face a number of limitations including downcycling of plastics, low efficiency and production of inferior materials. Hence, to achieve efficient plastic upcycling, different alternative catalytic approaches are being explored, which include electrocatalysis, photocatalysis and photo-electrocatalysis. These approaches offer sustainable, efficient avenues for the upcycling of wastes to valuable chemicals. In this review article, we focus on advances made in the development of efficient catalyst materials for different upcycling processes with a special emphasis on their role in improving the stability, selectivity and efficiency of upcycling processes. Additionally, different approaches including doping, heterostructure formation and composite development employed for enhancing the efficiency of upcycling processes are discussed. Furthermore, insights into the mechanisms and challenges involved in various reported upcycling processes are discussed, highlighting the potential of diverse catalyst systems to be used in the future for achieving the goals of circular economy.