Fabrication of superhydrophobic Ag@ZnO@Bi2WO6 membrane disc as flexible and photocatalytic active reusable SERS substrate

Abstract

Nowadays, there is a great influence of the innovated semiconductor heterojunction on the improvement of photocatalysis in organic pollutants elimination and the Raman signals multiplexing towards quantitative determination. Here, it was an attempt to develop a heterostructure membrane-based platform employing a filtration system to degrade and detect various target molecules at trace level in liquid samples. Herein, the ZnO nanorods/Bi2WO6 nanocomposites (ZBW) were prepared by a moderate temperature hydrothermal method; thereafter ZBW was encrusted with in-situ photoreduced silver nanoparticles (AgNPs) to form AgNPs@ZBW (Ag@ZnO@Bi2WO6) platform. The superhydrophobic AgNPs@ZBW platform encompasses both photocatalytic degradation of rhodamine B (RhB) under UV-irradiation and label-free surface-enhanced Raman scattering (SERS) evaluated for rhodamine 6G (R6G) and RhB. The AgNPs@ZBW exhibited superior photocatalytic and SERS activities for organic dyes degradation. As a result, the photocatalytic efficiency for dyes was 97.95% in 140 min. From the recycling experiment, it was manifested that AgNPs@ZBW maintained superb photocatalytic activity and stability after five cycles of use for SERS analysis. As-prepared platform displayed a scalable SERS response from 100 µM to 1 nM and enhancement factor of 3.2 × 105 and 1.2 × 105 for R6G and RhB, respectively, using an excitation wavelength of 532 nm, laser power of 3.2 mW and time of exposure of 10 s. Displayed trending of superhydrophobic membrane-based SERS substrates is assumed to lead abounds of change in the field of photocatalytic materials, SERS assay, and organic chemical analysis.