Metal Organic Chalcogenolate Heterostructures as Robust Photocatalysts for Environmental Dye Degradation

Abstract

Metal organic chalcogenolate (MOCs) are emerging hybrid organic–inorganic materials with tunable electronic structures and promising optoelectronic properties, yet their potential as robust photocatalysts for environmental remediation remains largely unexplored. Here, we report an AgSePh/TiO2 heterostructure photocatalyst prepared by integrating hot-injection-synthesized AgSePh nanocrystals with TiO2 through an ultrasonication-assisted assembly method. The optimized AgSePh/TiO2 composite containing 10 mg of AgSePh per 100 mg of TiO2 (10-AT) achieved 99.6% degradation of Rhodamine B (RhB) under light irradiation, substantially outperforming pristine AgSePh and TiO2. Spectroscopic and photoelectrochemical analyses reveal that coupling AgSePh with TiO2 promotes interfacial charge separation and transfer, as evidenced by photoluminescence quenching, prolonged carrier lifetime, reduced charge-transfer resistance, and enhanced transient photocurrent response. Radical scavenging experiments identify photogenerated electrons, superoxide radicals, and hydroxyl radicals as the dominant reactive species, supporting a Z-scheme charge-transfer pathway. The 10-AT photocatalyst further exhibits strong environmental robustness, maintaining high activity under varying pH conditions, in the presence of coexisting inorganic ions and natural organic matter, across different water matrices, and over eight consecutive recycling cycles. This work establishes MOC/TiO2 heterostructures as efficient and environmentally robust photocatalysts and highlights interfacial engineering as a viable strategy for expanding MOCs into photocatalytic water treatment applications.