Solar-Driven CO₂-Mediated Upcycling of Waste Plastics Into Value-Added Syngas and Carbon Nanotubes

Plastics and CO₂ are two major waste carbon resources, and their management and recycling are attracting increasing attention. CO₂-mediated plastic upcycling represents a promising strategy for the simultaneous transformation of both wastes, yet it still suffers from high energy demand, low efficiency, and limited applicability to diverse plastics. Here, we report a solar-driven photothermal strategy that enables the efficient and energy-saving CO₂-mediated reforming of various plastics, including polyolefins, polyesters, copolymers, and their mixtures, into high-value syngas and carbon nanotubes (CNTs). The process achieves a syngas yield of 165.6 mmol g_cat ^-1 h^-1, an order of magnitude higher than that of conventional thermocatalysis. Within this system, CO₂ acts not only as an oxidant that consumes the hydrogen species released during plastic dehydrogenation, thereby enhancing efficiency and suppressing methanation but also as a carbon feedstock that directly contributes to both gaseous and solid products. This study provides a powerful solution for the valorization of complex plastic wastes and greenhouse gases and offers new insights into solar-driven chemical transformations toward a circular carbon economy, while further optimization of the H₂/CO ratio may expand its compatibility with specific downstream applications.