Enhanced visible-light-driven photocatalytic degradation by metal wire-mesh supported Ag/flower-like Bi2WO6 photocatalysts

The major problems for photocatalysts are the poor visible light-driven activity, separation process for the recycling of photocatalysts, and fast recombination of photoexcited carriers. We tried to solve these problems by the growth of Bi2WO6 flower nanostructures on the conductive wire mesh substrates, and the deposition of Ag nanoparticles on Bi2WO6 using a double-potentiostatic electrodeposition method to make the visible-light driven metal wire mesh/Ag-Bi2WO6 as an immobilized photocatalyst. Close contact among Bi2WO6 with Ag nanoparticle and metal wire mesh facilitated effective separation of photoexcited charges, leading to improved photocatalytic activities. The results of diffuse reflection spectra, electrochemical impedance spectra, and photocurrent response confirmed the enhanced charge separation and increased optical absorption by the decoration of Ag nanoparticles. The optimized wire mesh/Ag-Bi2WO6 photocatalyst exhibited a high visible-light driven activity. Rhodamine B was completely degraded within 60 min of irradiation. Three-dimensional flower-like Bi2WO6 nanostructure and wire-mesh structure of the substrate maximize the contact area between photocatalyst and the dye molecules. Decorated Ag nanoparticle extended the range of absorption wavelength from UV light to visible light region. The immobilized photocatalyst can be easily recycled and reused without centrifugation and filtration process. (C) 2019 Elsevier B.V. All rights reserved.