Full carbon upcycling of organophosphorus wastewater enabled by interface photolysis

Abstract

The key of wastewater treatment is to reduce the toxicity of organic pollutants and ideally undergo mineralization, typically accompanying the formation of greenhouse gas CO2 in large amounts. Here, a full carbon upcycling strategy for efficient valorization of organic phosphorus (OPs) contaminants enabled by interface photolysis was developed, in which the van der Waals interface effect based on the interfacial heterojunction interaction could efficiently regulate the electron density of the UCN/CdS NPs photocatalyst interface to benefit the construction of the interface-orienteering electron pump and edge active sites. The synergistic catalysis of ·OH on the C sites and holes on the Cd sites at the photocatalyst interface edge could realize the complete photodegradation of glyphosate wastewater in 2 h to exclusively afford gas fuel CO (4124 μmol g−1) and glycine (86 %), which was likewise applicable to an extensive scope of OPs for nigh quantitative carbon upcycling. Quantum calculations elaborated that the Cd edge sites with the ability to enrich holes induced by the van der Waals interface effect could reduce the activation energy of CP bond cleavage of glyphosate activated by ·OH, resulting in CP bond scission selectivity of ca. 91.5 %, which is vital to full carbon upcycling. The oriented interface engineering offers a more eco-friendly photocatalytic protocol to facilitate both wastewater treatment and carbon resource recovery.