The influence of different ratio of Sn4+ and Bi3+ on n-p SnO2/α∼ Bi2O3 composite structure and its photocatalytic properties by solid phase synthesis

Abstract

Abstract In this study, a novel n-p SnO2/α∼Bi2O3 composites were synthesized by the convenient and rapid in-situ solid-phase reaction synthesis. The different influence of ratios: n (Sn: Bi) = 2/1, 3/1, 1/1, 1/2 and 1/3 on the crystal shape, microstructure, specific surface area, optical absorption properties of the material and the separation ability of photocarriers were discussed. The study shows that: compared with pure SnO2, the light absorption boundary of all the composites have been widened to the visible light region, the larger the ratio of Sn in the sample, the more conducive it is to absorbing the visible light. However, greater ratio of Sn4+ ions in the sample will lead to a decrease in the separation ability of photo electrons and holes. Of which n(Sn: Bi) = 2/1 composite, photoelectrons and holes have the strongest separation ability. The Rhodamine B (Rh. B) solution can be almost completely decolorized within about 30 minutes under 400W halide light irradiation. The chemical reaction mechanism in the sample synthesis process was discussed in detail. This study not only synthesized excellent n-p SnO2/α∼Bi2O3 photocatalytic composites, but also provides references for in-situ synthesis of other semiconductors.