Synchronized surface oxygen states and electron-hole passage in microwave-assisted tungsten oxide for photocatalytic organic decomposition and antibacterial activity

The present study focuses on controlling the composition of microwave-fabricated tungsten oxide (WO3) nanoparticles through annealing at 500 °C. The significance of annealing on the surface oxygen states and the photocatalytic performance of WO3 nanoparticles were systematically investigated for the removal of organic pollutants and bacteria. The optimum photocatalyst, microwave-assisted WO3 which was successively annealed for 6 h and Pt-loaded (Pt/WO3-M-6 h) demonstrated high photocatalytic performances in inactivation (99 %) against E. coli and S. aureus as well as in degradations of Orange II dye (93 %) and BPA (99 %) under one sun illumination for 180 min. The integration of WO3-M-6 having a moderate amount of surface oxygen defects and Pt loading could provide the most favorable environment in charge transfer by reducing the electron-hole recombination and as an electron collector, respectively. Detailed mechanisms have been proposed for the photocatalytic decomposition of organic pollutants and the photocatalytic disinfection of waterborne bacteria.