Photocatalytic activity of binary and ternary SnO2–ZnO–ZnWO4 nanocomposites
•Binary and ternary SnO2–ZnO–ZnWO4 nanocomposites were prepared by a sol–gel method.•The samples were tested for the degradation of 4-nitrophenol and the synthesis of p-anisaldehyde under UV irradiation.•The high photoactivity was attributed to the presence of heterojunctions among different semiconductors.•An anti-correlation between oxidant power and selectivity of the various catalysts was found.
Binary and ternary SnO2–ZnO–ZnWO4 nanocomposites were prepared by a sol–gel route. The photocatalytic activity of the samples was evaluated through the decomposition of 4-nitrophenol and partial oxidation of 4-methoxybenzyl alcohol to p-anisaldehyde. All the mixed catalysts revealed higher photoactivity than bare ZnO, SnO2 or ZnWO4 and the best performances were exhibited by the binary nanocomposites. The high photocatalytic activity was explained by the presence of heterojunctions among different semiconductors that enhance the separation of the photogenerated electron–hole pairs, hindering their recombination. As a general consideration, an essential role was played by the electronic features of the samples in the degradation reactions whereas the surface properties were key factors for the selective formation of p-anisaldehyde.
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Journal: Journal of Photochemistry and Photobiology A: Chemistry - Volume 309, 15 August 2015, Pages 47–54