Nanostructured WO3·xH2O deposition effects on the antimicrobial activities of nano TiO2-coated bamboo

Antibacterial and antifungal activities of nanostructured WO3·xH2O (x = 0.33 or 1) decorated TiO2 films on bamboo surfaces were evaluated for the first time. Anatase TiO2 films were easily loaded on the surface of bamboo (TB) by a hydrothermal method. Nanostructured WO3·xH2O (x = 1 or 0.33) with different crystal phases were respectively synthesized on TB by adding (O-WTB) or not adding (WTB) oxalic acid employing a hydrothermal method. Both O-WTB and WTB demonstrated obvious synergistic antibacterial abilities against Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus) and good outdoor antifungal ability of 60-day experiment. The electron paramagnetic resonance (EPR) spectra of •O2ˉ and •OH radicals showed that the antifungal activity of O-WTB and WTB was due to their good photocatalytic activity and synergistic antifungal effect with hybrid structure, respectively. Nanostructured WO3·xH2O with different crystal phases displayed differentiated antimicrobial activities and can be employed as potential antimicrobial agents.