Full-spectrum photocatalytic treatment and in situ upcycling of organophosphorus wastewater enabled by biomimetic urchin-like Bi₂S₃/CdS

Abstract

High-efficiency photo-degradation organophosphorus pollutants into value-added chemicals, reducing or avoiding CO2 emission, is challenging but significant for environmental protection and carbon neutrality. Herein, a novel biomimetic urchin-like Bi2S3/CdS (BCS-UL) photocatalyst with full spectral response was developed for thorough degradation of glyphosate (Gly) and in situ upcycling into CO (731 μmol g-1h−1). Control experiments, finite element simulations, and theoretical calculations corroborated that Z-scheme heterojunction BCS-UL achieved highly photothermal/pyroelectric properties by multiple scattering and reflection of near-infrared light among spines of Bi2S3 component, which could promote the transfer of electron-hole pairs and regulate the selective formation of reactive oxygen species •O2–. The active center CdS component promoted C-P bond activation of Gly, which was more susceptible to being converted into sarcosine and further to CO by nucleophilic attack with •O2– and oxidation with h+. The decomposition pathways of Gly and acute toxicity of the intermediates were analyzed with LC-MS, Fukui index, and theoretical calculation. Moreover, BCS-UL was applicable for the efficient degradation of Gly at low concentrations over a wide pH range and could be recycled at least 5 times with no evident decline in catalytic activity. The biomimetic manufacturing technology provides a new avenue for implementing synchronously high-performance photocatalytic treatment and oriented upcycling of organic pollutants.