Effect of hydrothermal temperature on the antibacterial and photocatalytic activity of WO3 decorated with silver nanoparticles

Abstract

We studied the catalytic and antimicrobial properties of hierarchical architecture of WO3.Ag synthesized at 100, 150, and 200 °C by a very simple and reliable hydrothermal technique. The investigation carried out by XRD showed the amorphous nature of sample grown at 100 °C, while those at 150 and 200 °C crystalline nature of 3D WO3.Ag was confirmed. From FESEM and HRTEM results, it was evident that the silver nanoparticles grew in a 3D WO3.Ag host matrix. The average diameter of Ag nanoparticles by HRTEM was around 5–15 nm. Photocatalytic activities of as-prepared samples were evaluated by the degradation of rhodamine B (RhB). Samples prepared at 150 and 200 °C showed higher activity in comparison to sample prepared at 100 °C. This can be mainly attributed to the suppression of traps states and electron/hole pairs recombination as highlighted by the photoluminescence results. The as-synthetized samples showed promising antimicrobial features against various bacterial strains. The 100 °C WO3.Ag nanospheres exhibited the highest antibacterial activity, with very low minimum inibitory concentration (MIC) values (4.0–8.0 μg/ml) when compared with 150 and 200 °C samples.