Plastic-to-Treasure: Innovative advances in photo/electro-catalytic upcycling technologies for commodity chemicals and fuels

Abstract

Plastics are one of the greatest inventions of the 20^th century that bring convenience to mankind. Owing to the commercialization of plastics, plastic pollution has become a petrifying environmental issue as the demand for plastic products overwhelms plastic recycling rates. However, the conventional methods (i.e., pyrolysis and gasification) require high pressure and temperature to treat waste plastic, resulting in ineluctably energy-waste and secondary pollution. On the contrary, selective catalylic technologies provide a green approach to degrade plastics whilst also reforming them into value-added chemicals and fuels. In this review, innovative green approaches, including photocatalysis, electrocatalysis, and photoelectrocatalysis, have been comprehensively reviewed from the perspective of sustainable use of resources. Distinctive emphasis is placed on highlighting the merits of each technology and enlightening the state-of-the-art modification strategies that strengthen the pillars of catalytic activities. The transformation of plastics with the above techniques is also elaborated in terms of the reaction conditions and products from various plastic waste as substrates. With a feasibility breakdown for each technology displayed in this study, insights on the challenges and prospects of innovative green technologies for plastic upcycling are underscored as well to facilitate the society moving toward a plastic circular economy.