Solar-Driven Dehalogenation and Upcycling of Brominated Plastic Waste

Chemical recycling of brominated plastic waste necessitates the concurrent mitigation of hazardous brominated compounds and the preservation of valuable hydrocarbons, which remains unachievable with conventional thermochemical methods. Here, we report that such a dilemma has been resolved by a solar-driven method using a bifunctional material comprising nanoscale zerovalent iron (nZVI) dispersed on a HZSM-5 zeolite. Under sole light irradiation, the nZVI intensively absorbs photons and raises its temperature to trigger the photothermochemically partial cleavage of C-C/C-H bonds in polyolefins and polystyrene to produce condensable hydrocarbon fragments over HZSM-5, and immobilizes dissociated C-Br as a solid, stable FeBr₂ phase with >90% debromination efficiency. We demonstrate the scalability of this process with a 0.5 m × 0.5 m solar-driven apparatus that achieves a rapid plastic processing rate of 1.93 g_plastic cm^-2·h^-1. This solar-driven one-step strategy offers a sustainable path for decontaminating and valorizing real-world additive-laden plastic waste.