Design of novel photoactive modified titanium silicalites and their application for venlafaxine degradation under simulated solar irradiation

Abstract

Titanium silicalites (TS) are well-known materials for their use in industrial oxidation reactions, and although they are used as photocatalysts, their activity is limited. Therefore, numerous synthetic strategies are investigated to improve their photocatalytic activity. Herein, three series of modified titanium silicalites are synthesized using three different organotriethoxysilanes at different molar percentages with the aim of modifying the structure of the zeolite, both at a porous and chemical level, to obtain materials with high photocatalytic activity. The study of their morphological, textural, chemical, and UV–vis light absorption properties through various characterization techniques has allowed the selection of the best candidates to test their photoactivity in the degradation of venlafaxine, an antidepressant drug that persists as a contaminant in wastewater and has serious neurotoxic effects. Materials synthesized using a 5% molar percentage of RTEOS and 10% of PhTEOS (Ph = phenyl) are able to degrade venlafaxine, whereas the reference material does not show any photocatalytic activity. These results lead the way to use this synthetic strategy to develop titanium silicates and optimize their photocatalytic activity in degradation reactions of different pollutants.