Developing nanostructured composite of poly(triazine imide) and titanium dioxide for selective photooxidation

Abstract

Pure semiconductors are rarely suggested as efficient heterogeneous photocatalysts, as they exhibit low efficiency, because of high recombination rate and narrow adsorption spectrum. Instead, various composites are proposed where intimate contact between two phases creates heterojunction, that improves photoactivity. Another challenge is morphology development. Heterogeneous photocatalyst must have an increased surface exposed to a reaction mixture to create structural prerequisites for better reagent diffusion, and photoseparated charges migration. Nanostructured materials meet these requirements. Being composed of smaller structures assembled regularly, nanostructures exhibit higher specific surface and well-developed pores, making them appealing substrates for photocatalysts. Problem is they are hard to get with conventional synthetic protocols. Recently emerged poly(triazine imide) as a non-metal based semiconductor proved applicable in photocatalysis, yet showed compromised selectivity. In pursuit of more selective catalysis, it was subjected to coupling with transition metal oxide. As a result, we developed a novel grain-like nanostructure of photoactive composite based on poly(triazine imide) (PTI) and anatase, which was efficient in benzyl alcohol (BA) oxidation and provided targeted benzaldehyde (BAl) with 94% selectivity at 100% conversion.