Reinforcing the Efficiency of Plastic Upgrading through Full-Spectrum Photothermal Effect Integration of Heat Isolator.

Photoreforming of polyethylene terephthalate (PET) to H is practically attractive strategy for upgrading waste plastics. The major challenge is to utilize the infrared energy in the solar spectrum to improve the efficiency for photoreforming of PET to H. Herein, through the ingenious integration of tungsten phosphide nanoparticles and tungsten single atoms (WP/W SAs) with carbon nitride (g-CN), the constructed hybrid inherits both the desirable properties and structural merits of the respective building blocks. Specifically, the photothermal effect of WP/W SAs couples with the "heat isolator" role of g-CN due to its low thermal conductivity, thereby forming localized high-temperature regions, reducing the activation energy and improving the kinetics in the photoreforming of PET to H. Additionally, the green pretreatment of PET using alkali-free hydrothermal strategy is reported, achieving direct separation of the ethylene glycol and terephthalic acid. This work not only provides an alkali-free hydrothermal pretreatment for PET, but also integrates the photothermal effect with the thermal insulation and opens a new avenue for harnessing solar energy into to convert plastics into H.