Adsorption and photocatalytic-conjugated activity of a chitosan-functionalized titanate coating for the removal of the drug clonazepam from drinking water

Pável César Hernández-Del Castillo; Verónica Castro-Velázquez; Vicente Rodríguez-González

doi:10.1007/s11356-023-30215-2

Adsorption and photocatalytic-conjugated activity of a chitosan-functionalized titanate coating for the removal of the drug clonazepam from drinking water

Environ Sci Pollut Res Int. 2023 Oct 7. doi: 10.1007/s11356-023-30215-2. Online ahead of print.

Authors

Pável César Hernández-Del Castillo¹, Verónica Castro-Velázquez², Vicente Rodríguez-González²

Affiliations

¹ División de Materiales Avanzados, Instituto Potosino de Investigación Científica y Tecnológica A. C., SLP, 78216, San Luis Potosi, Mexico. pavel.hernandez@ipicyt.edu.mx.
² División de Materiales Avanzados, Instituto Potosino de Investigación Científica y Tecnológica A. C., SLP, 78216, San Luis Potosi, Mexico.

PMID: 37804383
DOI: 10.1007/s11356-023-30215-2

Abstract

This research evaluated H₂TiO₇ nanotubes (TiNTs) functionalized with 1 (1TiCN), 5 (2TiCN), and 10 (3TiCN) wt.% of chitosan for the removal of clonazepam by an adsorption/photocatalysis-conjugated method. The samples were immobilized on glass, and their mechanical stability was tested by washings. The functionalization of the samples was verified by the FTIR and DRS techniques. SEM images displayed nanotubes in the samples and thickness of 4.24 μm for the 2TiCN coating. The chemical composition of the 2TiCN coating was obtained by EDS. The XRD patterns evidenced chitosan and titanate phases in the functionalized samples. Furthermore, the 2TiCN coating was evaluated in the removal of clonazepam, reaching 80.79% (4.38 and 49.64% more than the TiNT and commercial TiO₂ powders, respectively) after 240 min and being 6.88% more efficient after 4 reuses than the 2TiCN powders. OH^- ions were the main oxidizing species found by scavenger tests. The surface area of 2TiCN (168.6 m²/g) was 2 times higher than that of TiNTs, and its bandgap (2.95 eV) was the lowest. Therefore, the 2TiCN coating is an excellent alternative to remove clonazepam.

Keywords: Adsorption-photocatalysis; Chitosan; Clonazepam; Immobilized nanotubes; Spin coating; Titanate functionalized.