Composite CdS/TiO2 Powders for the Selective Reduction of 4-Nitrobenzaldehyde by Visible Light: Relation between Preparation, Morphology and Photocatalytic Activity

A series of composite CdS/TiO2 powders was obtained by nucleation TiO2 on CdS nanoseeds. This combination presents the appropriate band edge position for photocatalytic redox reactions: visible light irradiation allows injection electrons into dark TiO2, increasing lifetimes separated charges. The have been used quantitative photoreduction 4-nitrobenzaldehyde to 4-aminobenzaldehyde, whose formation pointed out 1H NMR and ESI-MS positive ion mode. Concomitant sacrificial oxidation 2-propanol, which also proton source, occurred. use characterization techniques (XRD, N2 adsorption-desorption) evidenced principal factors driving reaction: nanometric size anatase crystalline domains, presence dispersed form an extended active junction CdS/anatase, mesopores as nanoreactors. result is efficient system that uses light. In addition, in with improves stability photoactive material, enabling its recyclability.