ISSN print edition: 0366-6352 ISSN electronic edition: 1336-9075 Registr. No.: MK SR 9/7 Published monthly

Chemical exfoliation of silica filters used on methylene blue degradation by photocatalysis

María E. Zarazúa-Morín, Arturo S. Galindo-Luna, Víctor J. Gallegos-Sánchez, and Isaías Juárez-Ramírez

Departamento de Ecomateriales y Energía, Facultad de Ingeniería Civil, Universidad Autónoma de Nuevo León, UANL, Av. Universidad S/N, San Nicolás de los Garza, Mexico

E-mail: elvira.zarazuamrn@uanl.edu.mx

Received: 7 January 2022  Accepted: 26 April 2022

Abstract:

The monolithic silica filters here studied were chemically exfoliated by hydrothermal method to modify their physical–chemical properties and optimize photodegradation of methylene blue dye (MB). XRD results revealed an increase in the α-cristobalite phase when it was exposed to higher hydrothermal temperature. Meanwhile, SEM analyses showed a correlation between surface cracking with increased temperature and reaction time. The exfoliated filters increase the adsorption capacity of the molecule up to 2.5 times and show a degradation efficiency of 94% in 5 h of reaction, maintaining the efficiency at 60% after three cycles. Results show a correlation between photodegradation capacity with the morphological stability of the filter. The efficiency is attributed to the exfoliation and presence of pores in the surface, product of the hydrothermal reaction. Therefore, the use of exfoliated monolithic filters is presented as an innovative alternative for its practicality and reproducibility for the scaling up of water treatment processes.

Graphical abstract

Keywords: Silica monolith; Filters; Design of experiment (DOE); Hydrothermal method; Photocatalytic degradation; Methylene blue dye

Full paper is available at www.springerlink.com.

DOI: 10.1007/s11696-022-02253-6

Chemical Papers 76 (9) 5627–5642 (2022)