Room temperature synthesis of GO/Ag2O nanocomposite: Broad spectral ranged solar photocatalyst and high efficacy antibiotic for waste water treatment

With the worldwide industrial growth, major concern is rapid surge in water pollution. Notably, the water is contaminated by strong industrial dyes and pathogenic microorganisms. To address the issue, a simple heterostructure GO/Ag2O was synthesized in room temperature, which can serve the purpose of industrial waste management. In general, Ag2O nanostructures with absorptivity in NIR range is able to absorb 57% of solar spectrum, but our synthesized Ag2O nanowires can absorb Visible-NIR spectral range (peak ~ 850 nm) due to presence of multiple energy states, confirmed by the density of states (DOS) of Ag2O using density functional theory (DFT) analysis. Developing a nanocomposite with graphene oxide exhibited blue shifting of absorption maximum at 700 nm and improved absorptivity covering the entire solar spectrum (200–1800 nm). The DFT analysis of designed geometrical relaxed structure of GO/Ag2O approved the unique optical properties of nanocomposite. The nanocomposite degraded a very strong medical dye (Safranin-O) for 40 min white light exposures. In addition, our nanocomposite also showed antibacterial activity against E. coli with an MBC ~ 0.01 mg/ml. Molecular Docking analysis also established the improved interaction of an E.coli ribosomal and membrane protein with GO in nanocomposite in comparison with that of pure GO, which supports the experimental results. Fast charge transfer between Ag2O and GO increases the super oxide and hydroxide radicals in our synthesized hetero-system, which results excellent solar photocatalytic activity and ROS species to destroy the bacterial colonies.