Preparation of a new composite by reaction of SnBu3Cl with TiCl4 in the presence of NH4OH-photocatalytic degradation of indigo carmine

Reactions of SnBu3Cl, TiCl4 and NH4OH in ethanol followed by pyrolysis of the resultant product at 550 degrees C, either in an atmosphere of oxygen or hydrogen, yielding new SnO2-TiO2 based composites. In all, eight products were prepared with weight ratios of Sn-TiO2 of 0% (1), 5% (2), 15% (3) and 30% (4) in O-2 and 0%(5), 5%(6), 15% (7) and 30% (8) in H-2. XRD revealed diffraction patterns of TiO2 (anatase) in the composites, but not those of SnO2 due to its insufficient crystallinity. Scanning electron microscopy indicated the presence of Sn metal on the surface of composites 6-8. Sn-119 Mossbauer experiments revealed SnO2 in all samples, and increasing amounts of tin in samples 7 and 8, respectively. The composites were used in experiments of photocatalytic degradation of indigo carmine dye. The catalytic experiments monitored by mass spectrometry and electronic spectroscopy revealed that, in the conditions of the experiments, composite 8 displays the highest activity. In addition, degradation products were characterised using electrospray ionization mass spectrometry (ESI-MS and ESI-MS/MS) data. Copyright (C) 2010 John Wiley & Sons, Ltd.