Nano-architected titania/gold@GO nanosheets for sonocatalytic degradation of azo dyes in textile wastewater

Abstract

Environmental pollution is creating serious risks to both human health and the atmosphere which has been a major threat on a global scale. Therefore, it is necessary to focus on the evolution of the environment and trace contaminants for effective and reliable detection and degradation methods. Photochemical methods such as Surface-Enhanced Raman Scattering (SERS) and sono-catalytic degradation can be used to accelerate the detection and degradation of toxic dyes. In the present work, a Gold/Titania/Graphene oxide nanocomposite (ATG) was investigated as a capable dual substrate for SERS sensing and sono-catalytic degradation of pollutants. The nanosize distribution (6–12 nm) of ATG was synthesized by a solvothermal route. X-ray diffraction pattern illustrates the anatase phase of the titanium dioxide. Sonocatalytic degradation was aided using Raman spectroscopy. The effectiveness of ATG as a sono-catalytic substrate and SERS sensor was first evaluated using commercial dyes, such as malachite green and Bismarck brown. Furthermore, research has been conducted on the harmful elements in textile effluents (TE). The NN and C-N bands found in the SERS spectra of TE indicates the presence of carcinogenic azo-dye impurities. The enhancement factor was observed to be 5.77×1012 with the limit of detection (LOD) as 6.0×10−12M. Additionally, the sono-catalysis of ATG was evaluated for the elimination of these dye pollutants in TE. Following sono-catalysis by ATG, a high degradation rate constant of approximately 8.44 ×10−3/min was noted in TE with 89 % of degradation efficiency. The enhanced SERS detection, sono-catalytic degradation of synthetic dyes and effluent stem from the combined action of’ plasmonic characteristics of Au NPs, anatase TiO2, and the π-π stacking characteristic of GO.