Tailoring the exposed facets of anatase titania and probing their correlation with photocatalytic activity – an experimental and statistical study

Abstract

The present study is an attempt to understand the relation between the individual synthesis parameters of titania synthesized using deep eutectic solvent (DES) and the growth formation of reactive facets. The study indicated that until the attainment of a metastable state (550 °C), increasing oxygen vacancies were observed, which points towards the occurrence of the excitonic photoluminescence (PL) process and is well corroborated with the nanoparticle (NP) photocatalytic activity. Catalyst S3550 (precursor : DES: 1 : 3; calcined at 550 °C) exposed with the highly reactive {111}-facet exhibited the highest photocatalytic efficiency and showed its selectivity towards anionic dyes under acidic conditions. Furthermore, the statistical optimum initial concentration, catalyst loading, and pH were found to be 50 ppm, 1.2 g L⁻¹, and 4, respectively, with a high photocatalytic efficiency of 98.5% and 45% COD reduction and a degradation time of 30 min for Remazol Brilliant Blue R reactive dye under 125 W UV irradiation.