Photophysical and Photocatalytic Properties of BiSnSbO(6) under Visible Light Irradiation

BiSnSbO(6) with strong photocatalytic activity was first fabricated by a high-temperature, solid-state sintering method. The resulting BiSnSbO(6) was characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD), UV-vis diffuse reflectance spectroscopy (DRS) and X-ray photoelectron spectroscopy (XPS). The results showed that BiSnSbO(6), with a pyrochlore structure and a cubic crystal system by a space group Fd3m, was well crystallized. The lattice parameter or the band gap of BiSnSbO(6) was 10.234594 Å or 2.83 eV. Compared with N-doped TiO(2), BiSnSbO(6) showed higher photocatalytic activity in the degradation of benzotriazole and rhodamine B. The apparent first-order rate constant for BiSnSbO(6) in the degradation of benzotriazole and rhodamine B was 0.0182 min(−1) and 0.0147 min(−1), respectively. On the basis of the scavenger experiment, during the photocatalytic process, the main active species were arranged in order of increasing photodegradation rate: •OH < •O(2)(−) < h(+). The removal rate of benzotriazole or rhodamine B was approximately estimated to be 100% with BiSnSbO(6) as a photocatalyst after 200 min visible-light irradiation. Plentiful CO(2) produced by the experiment indicated that benzotriazole or rhodamine B was continuously mineralized during the photocatalytic process. Finally, the possible photodegradation pathways of benzotriazole and rhodamine B were deduced.