Heterostructured Photocatalytic Fabric Composed of Ag<sub>3</sub>PO<sub>4</sub> Nanoparticle-Decorated NH<sub>2</sub>-MIL-88B (Co/Fe) Crystalline Wires for Rhodamine B Adsorption and Degradation
Jinwook Lee, Jooyoun Kim
Abstract
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 (NH 2 -MIL-88B) and Ag 3 PO 4 catalysts. This study reveals that by controlling the Co/Fe molar ratio of NH 2 -MIL-88B (Co/Fe) (noted as MIL x ), the nanocrystal structures of the bimetallic MIL x and the associated heterojunction with Ag 3 PO 4 (noted as Ag/MIL x ) 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 MIL x (Ag/MIL x ) followed the charge transfer pathways of the Z-scheme, facilitating the generation of •O 2 – 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 Ag 3 PO 4 and single-metal NH 2 -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.