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

Photoreforming of polyethylene terephthalate (PET) to H₂ 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 H₂. Herein, through the ingenious integration of tungsten phosphide nanoparticles and tungsten single atoms (WP/W SAs) with carbon nitride (g-C₃N₄), 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-C₃N₄ 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 H₂. 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 H₂.