• Effect of reaction variables on facet-controlled synthesis of anatase TiO$_2$ photocatalysts

• # Fulltext

https://www.ias.ac.in/article/fulltext/boms/045/0059

• # Keywords

CTAB; TiO2 synthesis; microwave irradiation; hydrothermal; sol–gel method; photodegradation of organic pollutants.

• # Abstract

This study reports the effect of various reaction variables of a tailor-made sol–gel synthesis method on the morphology and photocatalytic behaviour of nanostructured anatase TiO$_2$ photocatalysts. Reaction variables like solvent effects, hydrothermal and microwave conditions, type of capping agents and calcination affect the TiO$_2$ crystal growth, and thereby, their optimal conditions are anticipated and discussed in detail. It is proposed that TiO$_2$ exposed with characteristic facets can be prepared by a hydrothermal-modified sol–gel method employing a quaternary solution system at pH 3 along with cetyltrimethylammonium bromide (CTAB) as the capping agent. The optimal hydrothermal temperature affected the restructuring and crystallization of TiO$_2$ by enhancing the phase transformation from amorphous to anatase. TiO$_2$ crystal growth under microwave assistance was faster, which primarily resulted in low-energy facets exposure. The primary determination of photocatalytic efficiency of the samples was obtained from the photodegradation profiles of model dye methylene blue. An interesting find was that TiO$_2$ synthesized under hydrothermal treatment in the presence of CTAB had a morphology determining behaviour at pH 3 favouring the selective stabilization of co-exposing high energy {010}/{100}, {001} and low energy {101} facets in TiO$_2$. The optimum percentage of high- and low-energy facets resulted in superior photocatalytic activity due to the spatial separation of photogenerated charge carriers. Furthermore, the present study has a great perspective on how particularly the reaction variables determine the direction of crystal growth of nano TiO2 and thereby its morphology that directly affect its photocatalytic efficiency.

• # Author Affiliations

1. Department of Polymer Science and Rubber Technology, Cochin University of Science and Technology, Kalamassery 682022, India
2. Inter University Centre for Nanomaterials and Devices, Cochin University of Science and Technology, Kalamassery 682022, India

• # Bulletin of Materials Science

Volume 46, 2023
All articles
Continuous Article Publishing mode

• # Dr Shanti Swarup Bhatnagar for Science and Technology

Posted on October 12, 2020

Prof. Subi Jacob George — Jawaharlal Nehru Centre for Advanced Scientific Research, Jakkur, Bengaluru
Chemical Sciences 2020