Bi0 nanoparticle loaded on Bi3+-doped ZnWO4 nanorods with oxygen vacancies for enhanced photocatalytic NO removal

Bi-0 nanoparticles-loaded on Bi3+-doped ZnWO4 (Bi/ZBWO) nanorods are prepared by a two-step hydrothermal-solvothermal method. The electron paramagnetic resonance (EPR) spectroscopy results show the formation of oxygen vacancies resulted from Bi3+ doping in the Bi3+-doped ZnWO4 (ZBWO). The as-prepared samples are applied in photo-oxidation removal of NO under simulated sunlight and vis-light irradiation. Among the samples, Bi/ZBWO exhibits the best photocatalytic performance than pure ZWO, ZBWO, and Bi-0-loaded ZnWO4 (Bi/ZWO). The NO removal efficiency of Bi/ZBWO reaches about 55.29% and 11.7% under simulated sunlight and visible light irradiation, respectively. The enhanced photocatalytic performance of Bi/ZBWO composite is attributed to the synergistic effect of the strong visible light absorption, the surface plasmon resonance (SPR), and the high separation efficiency of the photoinduced electron-hole pairs. The results from the trapping tests and electron spin resonance (ESR) spectra conclude that both the center dot O-2(-) and center dot OH radicals are the main active species for the photocatalytic process. (C) 2019 Elsevier B.V. All rights reserved.