Novel and solvent-free cochineal-assisted synthesis of Ag-Al2O3 nanocomposites via solid-state thermal decomposition route: characterization and photocatalytic activity assessment

Herein, silver-alumina nanocomposites have been synthesized via simple, novel, solvent-free and template-less solid-state thermal decomposition using cochineal powder as novel starting reagent for the first time. AgNO3 and Al(OH)(3) were utilized as silver and aluminum source, respectively. The prepared Ag-Al2O3 nanostructures were characterized extensively by means of X-ray diffraction, energy-dispersive X-ray analysis, scanning electron microscopy, transmission electron microscopy, Fourier transform infrared spectroscopy and UV-Vis spectroscopy. Effect of reaction time, temperature and cochineal powder on morphology and particle size of prepared products was investigated. The results exhibited that in presence of cochineal powder, as-prepared nanostructures show very high degree of purity and uniformity. In other words, because of remarkable antioxidant properties of cochineal, it prevents silver nanoparticles from sintering and oxidizing. The silver-alumina nanocomposite were evaluated as photocatalyst for the Rhodamine B degradation using visible light irradiation and showed significant photocatalytic efficiency.