Enhanced photocatalytic performance by the synergy of Bi vacancies and Bi0 in Bi0-Bi2-δMoO6

Bi vacancies and Bi-0 containing Bi2MoO6 (Bi-0-Bi2-delta MoO6) was synthesized by a facile chemical reduction method. The visible-light-driven photoactivity of Bi2MoO6 was enhanced by nearly 7 times due to the synergy of Bi vacancies and Bi-0. Based on the characterization of XRD, HRTEM, XRF, XPS, Raman, FTIR and PL, Bi vacancies and Bi-0 coexisted in the crystal lattice of Bi2MoO6, and a strong interaction between Bi-0 and Bi-2(-)delta MoO6 was observed. Bi vacancies were proved to enlarge the band gap to promote the separation of photogenerated electron-hole pairs, and Bi-0 can act as an electron trap to accelerate the charge transfer by its strong interaction with Bi2-delta MoO6, resulting in the high photoactivity of Bi-0-Bi2-delta MoO6 for the degradation of various organic pollutants under visible light. By the studies of ESR and other experiments, the charge transfer process was clarified that the fast separated electrons from Bi2-delta MoO6 by Bi vacancies were transferred to Bi-0 and further reacted to produce O-2(center dot-), and thus the photoexcited holes were accelerated to transfer to the surface of Bi2-delta MoO6 to oxidize water into more (OH)-O-center dot and directly degrade organic pollutants in water.