Construction of an oxygen-functionalized Ti3C2/NH2-MIL-68(In) Schottky heterojunction for the degradation of multiple organic pollutants

Abstract

Solar-driven photocatalysis offers a sustainable solution for organic pollutant degradation. Despite their ability to utilize visible light and enhance pollutant adsorption via coordinated unsaturated metal sites on metal–organic frameworks (MOFs), their efficiency is limited by rapid charge recombination and a lack of active sites. To address this, oxygen-functionalized Ti₃C₂/NH₂-MIL-68(In) (TC/MIL(In)) Schottky heterojunctions were prepared by an in situ hydrothermal process. The 1 wt% TC/MIL(In) composite exhibited exceptional photocatalytic activity, degrading 98.3% of RhB under visible light with 92.5% retention after six cycles. Experiments revealed that the optimal activity of 1 wt% TC/MIL(In) was observed under acidic conditions (pH 2.0–6.0). Additionally, TC/MIL(In) exhibited broad-spectrum degradation capabilities for multiple antibiotics. Mechanism studies revealed that holes (h⁺) play a major role, while photoelectrochemical and DFT calculations further revealed that the close interface contact between TC and MIL(In) optimizes charge dynamics. This work provides a strategic design for high-performance MOF-MXene hybrid photocatalysts in environmental remediation and elucidates the essential electron-transport channel at the Ti₃C₂-MOF junction.