Tailoring of visible light driven photocatalytic activities of Bi2MoO6 flower-like microspheres via synergistic effect of doping and surface Plasmon resonance

Series of Er3+/Yb3+-codoped Bi2MoO6 (Bi2MoO6:Er3+/xYb3+) and Bi2MoO6:Er3+/0.03Yb3+@Biy flower-like microspheres were designed to improve the visible light driven photocatalytic activities of Bi2MoO6 flower-like microspheres. The electronic structure of Bi2MoO6 host was analyzed through the first-principle density functional theory. Excited at 980 nm, glaring UC emissions are gained in Bi2MoO6:Er3+/xYb3+ compound and their strongest intensities are obtained at × = 0.05, where the corresponding mechanism is a two-photon absorption process. Through studying the tetracycline (TC) degradation under visible light irradiation, the photocatalytic activities of final products were explored. Compared with Bi2MoO6 flower-like microspheres, these samples doped with Er3+ and Yb3+ can remove TC more efficiently and the optimal performance is achieved when a = 0.03. Furthermore, via using the surface plasmon resonance (SPR) effect caused by metallic Bi, the photocatalytic activities of the designed samples were further manipulated, where the TC removal rate of Bi2MoO6:Er3+/0.03Yb3+@Bi0.10 flower-like microspheres is 91.0% after irradiating by visible light for 24 min. Moreover, the included photocatalytic processes are triggered by ·O2–, ·OH and h+ active species. Additionally, the TC solution treated by the designed photocatalysts shows non-toxicity to plants. These results imply that Bi2MoO6:Er3+/0.03Yb3+@Biy flower-like microspheres are potential visible light driven photocatalysts for wastewater purification and our finding may also provide guidelines for tailoring of the photocatalytic activities of semiconductors by synergistic effect of doping and SPR engineering.