Synthesis, characterization, antibacterial and photocatalytic performance of Ag/AgI/TiO2 hollow sphere composites

Dispersed TiO2 hollow spheres were successfully prepared which was obtained via Ostwald ripening under solvothermal conditions without any templates or surfactants. Then, the AgI/TiO2 was synthesized by the deposition-precipitation process. Finally, Ag/AgI/TiO2 was obtained by a photocatalytic reduction way. Their characteristics were analyzed by XRD, SEM, HRTEM, N-2 adsorption-desorption measurements and UV-vis absorption spectra. To demonstrate the potential applications of such composites, their antibacterial activity against Escherichia coli (E. coli) was studied by microcalorimetry for the first time, and their photocatalytic performance for degradation of different organic dyes under simulated UV and visible light was discussed. The results indicated that Ag/AgI/TiO2 hollow spheres revealed elevated antibacterial and photocatalytic activity because of their unique morphology, hollow structure and high surface area. The mechanism of the excellent antibacterial and photocatalytic activity of Ag/AgI/TiO2 hollow spheres are discussed which are attributed to the synergetic effect of Ag, AgI and TiO2. It suggested that the new Ag/AgI/TiO2 photocatalyst has broad application prospects in solar cell, sensor, antibacterial, catalysis and nanotechnology.