Solid state synthesis and characterization of n-p (SnO2)1.3/(α ∼ Bi2O3)x/(β ∼ Bi2O3)1-x photocatalyst modulated by PVA and its photocatalytic performance

A kind of n-p (SnO2)(1.3)/(alpha similar to Bi2O3)(x)/(beta similar to Bi2O3)(1-x) nanocomposite (SB-15) was synthesized with polyvinyl alcohol (PVA) as a template by solid state synthesis. XRD and HR-TEM confirmed the formation of n-p (SnO2)(1.3)/(alpha similar to Bi2O3)(x)/(beta similar to Bi2O3)(1-x). Particle size is found to be about 18 nm from HR-TEM images. FE-SEM clearly detected the boundary between SnO2 nanoparticles and Bi2O3 polyhedron particles. The special morphology and coexisting of alpha-Bi2O3 and beta-Bi2O3 in SB-15 make it have a stronger visible light absorption range as far as 725 nm. PL and photocurrent test shows that the SB-15 has the best photocarriers separation capability. About 99% decolorization ratio of Rh.B was achieved in only 5 min. About 70% Cr6+ was degraded within 20 min and it is about 60% for tetracycline in the coexisting system (Te with Cr6+ solution), introducing it as a promising photocatalytic material. This work has addressed the method of phase-selective synthesis of n-p SnO2/alpha similar to Bi2O3/beta similar to Bi2O3 by convenient solid state synthesis, which should be useful for the studies of other composites.