Article ID Journal Published Year Pages File Type
61035 Journal of Catalysis 2014 9 Pages PDF
Abstract

•Synthesis of anatase with well-defined crystallite size and crystallinity.•The photo-reactivity of anatase is independent with the crystallinity.•Increase the crystallite size of anatase enhances the photocatalytic performance.•The crystallite size dictates the phenol decomposition mechanism.

Crystallite size and crystallinity have been recognized as important parameters that influence the photocatalytic performance of pristine TiO2 nanoparticles. But how these two parameters individually affect the photo-reactivity of TiO2 remains unclear and debated due to the difficulties in preparing well-controlled TiO2 photocatalysts that vary crystallite size and crystallinity independently. Here, we have studied the effect of crystallite size and crystallinity on phenol photo-decomposition using well-defined anatase nanoparticles synthesized under supercritical water–isopropanol conditions. The photo-reactivity was found to increase with increasing crystallite size but to be independent of the crystallinity. By tracking the evolution of phenolic intermediates, we explored the reaction kinetics and demonstrated that an increase in the crystallite size of anatase nanoparticles can significantly suppress undesired hydroquinone–benzoquinone redox reactions and thus promote the full decomposition of phenol and phenolic compounds.

Graphical abstractThe effect of crystallite size and crystallite on the photoreactivity of anatase was studied by phenol photodecomposition. It was found that the decomposition process was strongly influenced by the crystallite size but not by the crystallinity. Increasing the crystallite size led to a significant suppression of undesired hydroquinone-benzoquinone redox reactions thus enhanced the photoreactivity of anatase.Figure optionsDownload full-size imageDownload high-quality image (164 K)Download as PowerPoint slide

Related Topics
Physical Sciences and Engineering Chemical Engineering Catalysis
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