Highly photoactive Brookite and Anatase with enhanced photocatalytic activity for the degradation of indigo carmine application

• Crystalline TiO2 Brookite and Anatase were synthesized by a facile and low temperature solution method.
• Both Brookite and Anatase were assessed for dye discoloration in a microfluidic photoelectrochemical reactor.
• Differences in photocurrent generation and oxidizing power were explained in terms of electrical properties and relative energy levels.

TiO2 Brookite, and Anatase powders were prepared by a facile and low temperature solution based method. XRD diffractometry was performed to confirm their phase composition and crystallinity. Morphology was further confirmed by TEM. N2 adsorption was used to determine surface area and pore size distribution. The difference in capacitive properties of both materials and the determination of the flat band position was obtained by Mott-Schottky analysis. Diffuse reflectance and Tauc plots allowed to obtain the band gap value. The degradation of Indigo Carmine dye with both catalysts in a photo-electrochemical microreactor was assessed by UV–vis, and Raman spectroscopy. Both materials were more active than the benchmark commercial Degussa P25 sample in the order P25 < Anatase < Brookite and explained in terms of energy band positions.

Figure optionsDownload as PowerPoint slideThe assessment of discoloration power of indigo carmine on Brookite versus Anatase in a photo-electrochemical microreactor.