Boosted Photoreforming of Plastic Waste <i>via</i> Defect-Rich NiPS₃ Nanosheets

Abstract

Sustainable conversion of plastic waste to mitigate environmental threats and reclaim waste value is important. Ambient-condition photoreforming is practically attractive to convert waste to hydrogen (H₂); however, it has poor performance because of mutual constraint between proton reduction and substrate oxidation. Here, we realize a cooperative photoredox using defect-rich chalcogenide nanosheet-coupled photocatalysts, e.g., d-NiPS₃/CdS, to give an ultrahigh H₂ evolution of ∼40 mmol g_cat^-1 h^-1 and organic acid yield up to 78 μmol within 9 h, together with excellent stability beyond 100 h in photoreforming of commercial waste plastic poly(lactic acid) and poly(ethylene terephthalate). Significantly, these metrics represent one of the most efficient plastic photoreforming reported. <i>In situ</i> ultrafast spectroscopic studies confirm a charge transfer-mediated reaction mechanism in which d-NiPS₃ rapidly extracts electrons from CdS to boost H₂ evolution, favoring hole-dominated substrate oxidation to improve overall efficiency. This work opens practical avenues for converting plastic waste into fuels and chemicals.