Synthesis of a reusable magnetic photocatalyst based on carbon xerogel/TiO2 composites and its application on acetaminophen degradation

Abstract

This work describes the production photocatalyst in two steps, (1) production of N-CXTi nanocomposites by sol-gel polymerization of resorcinol-formaldehyde-melamine in the presence of K2TiF6 inorganic metallic salt with TiO2 as precursor; (2) Synthesis of the Fe3O4/N-CXTi and Fe3O4/SiO2/N-CXTi nanocomposites by mechanical mixing of N-CXTi and magnetic nanoparticles. The magnetic nanoparticles (Fe3O4 and Fe3O4/SiO2) were prepared by a chemical co-precipitation method and subsequent functionalization by silica (SiO2). The materials were characterized by thermogravimetric analysis, Fourier transform infrared spectroscopy, scanning and transmission electron microscopy, X-ray diffractometry, and textural properties. The composites presented a morphology heterogeneous structure and the presence of two phases for the introduction of TiO2. The region was formed by amorphous carbon and carbon spheres, where Ti is detected only immersed in the amorphous carbon particles, in the anatase and rutile phase, and the presence of magnetic nanoparticles is located surrounded by the carbon structure. Results for the recovery and reuse of the photocatalyst Fe3O4/SiO2/N-CXTi presented the highest efficiency in the removal of the acetaminophen (APP) in the aqueous medium; the result of the reaction carried out in the presence of ultraviolet irradiation showed that the magnetic photocatalyst removed 99.2% of APP in an aqueous medium. Results for the recovery and reuse of the photocatalysts for nine consecutive reactions showed that they can be separated from the reaction medium in a simple and fast way, without significant losses of photocatalytic efficiency and excellent recovery of the photocatalyst.