Heterostructured Photocatalytic Fabric Composed of Ag3PO4 Nanoparticle-Decorated NH2-MIL-88B (Co/Fe) Crystalline Wires for Rhodamine B Adsorption and Degradation

As an effective and robust wastewater treatment method, a photocatalytic fabric featuring the Z-scheme heterojunction was developed by combining a Co/Fe bimetallic metal–organic framework (NH2-MIL-88B) and Ag3PO4 catalysts. This study reveals that by controlling the Co/Fe molar ratio of NH2-MIL-88B (Co/Fe) (noted as MILx), the nanocrystal structures of the bimetallic MILx and the associated heterojunction with Ag3PO4 (noted as Ag/MILx) were manipulated to perform higher adsorption and accelerated photocatalytic reaction for removing Rhodamine B (RhB) pollutant in water. Photoelectrochemical investigation and scavenging experiments revealed that heterojunction catalysts with bimetallic MILx (Ag/MILx) followed the charge transfer pathways of the Z-scheme, facilitating the generation of •O2– by increasing the conduction band energy position. As a result, at the optimal Co/Fe molar ratio of 0.2 in the heterojunction cocatalyst, RhB adsorption performance was improved by 28% and the RhB degradation was accelerated by 1.5 times compared to the heterojunction formed with Ag3PO4 and single-metal NH2-MIL-88B (Fe). The material developed in this study offers a unique advantage compared to other catalytic materials by strategically utilizing both crystal defects and heterojunction design to enhance the photocatalytic performance. This study is significant in providing crucial empirical evidence that is insightful for designing an effective photocatalytic self-cleaning material composed of complex cocatalytic nanocrystals for enhanced wastewater remediation.