One step solid-state reaction synthesis, characterization, and catalytic performance of n-p SnO2/Bi2O3 composite

A novel n-p SnO2/Bi2O3 composite was synthesized by template free one step solid-state reaction synthesis. The as-prepared composite was characterized by XRD, HR-TEM, FE-SEM, UV-Vis, PL, and XPS. The photocatalytic capacity of n-p SnO2/Bi2O3 was evaluated by monitoring the decolorization of Rh.B solution. The results indicate that: (1) The photocatalyst exhibited a unique flake-like powder structure. SnO2 particles closely scattered on the surface of nano-flake structure of Bi2O3; (2) Compared with pure SnO2 and Bi2O3, all the composite samples extended the edge of absorbance to visible light region as long as 520 nm(sample S500) ; (3) The composite calcined at 500 aintegral(sample S500) showed the highest separation capability of photo electrons and holes; (4) About 99% Rh.B can be completely decolorized within 30 min, and the reaction rate constant of S500 is about 10 times higher than that of pure SnO2 and Bi2O3; (5) The decolorization ratio was as high as 95% even in the 5th cycle which means the SnO2/Bi2O3 composite is chemically stable; (6)Active species test showed that (center dot O-2 (-)), holes (h(+)) were the main active species during the decoloration of the Rh.B solution.