Photocatalytic Removal of Metronidazole Antibiotics from Water Using Novel Ag-N-SnO2 Nanohybrid Material

Md Shahriar Hossain Shuvo; Rupna Akther Putul; Khandker Saadat Hossain; Shah Md Masum; Md Ashraful Islam Molla

doi:10.3390/toxics12010036

Photocatalytic Removal of Metronidazole Antibiotics from Water Using Novel Ag-N-SnO₂ Nanohybrid Material

Toxics. 2024 Jan 2;12(1):36. doi: 10.3390/toxics12010036.

Authors

Md Shahriar Hossain Shuvo¹, Rupna Akther Putul¹, Khandker Saadat Hossain², Shah Md Masum¹, Md Ashraful Islam Molla¹

Affiliations

¹ Department of Applied Chemistry and Chemical Engineering, Faculty of Engineering and Technology, University of Dhaka, Dhaka 1000, Bangladesh.
² Nanophysics and Soft Matter Laboratory, Department of Physics, Faculty of Science, University of Dhaka, Dhaka 1000, Bangladesh.

Abstract

In this study, we employed a straightforward synthetic approach using the sol-gel method to fabricate a novel photocatalyst, Ag and N co-doped SnO₂ (Ag-N-SnO₂). The synthesized photocatalysts underwent characterization through various techniques including XRD, FTIR, FESEM-EDS, TEM, UV-vis DRS, BET, and XPS. The UV-vis DRS results confirmed a reduction in the bandgap energy of Ag-N-SnO₂, leading to enhanced absorption of visible light. Additionally, TEM data demonstrated a smaller particle size for Ag-N-SnO₂, and BET analysis revealed a significant increase in surface area compared to SnO₂.The efficiency of the Ag-N-SnO₂ photocatalyst in degrading metronidazole (MNZ) under natural sunlight surpassed that of SnO₂. Under optimal conditions (Ag-N-SnO₂ concentration of 0.4 g/L, MNZ concentration of 10 mg/L, pH 9, and 120 min of operation), the highest MNZ photocatalytic removal reached 97.03%. The reaction kinetics followed pseudo-first-order kinetics with a rate constant of 0.026 min^-1. Investigation into the mineralization of MNZ indicated a substantial decrease in total organic carbon (TOC) values, reaching around 56% in 3 h of sunlight exposure. To elucidate the photocatalytic degradation mechanism of MNZ with Ag-N-SnO₂, a scavenger test was employed which revealed the dominant role of ^•O₂^-. The results demonstrated the reusability of Ag-N-SnO₂ for up to four cycles, highlighting its cost-effectiveness and environmental friendliness as a photocatalyst.

Keywords: Ag-N-SnO2; metronidazole; nanohybrid material; photocatalytic degradation; sunlight.

Grants and funding

This research was funded by the University Grants Commission (UGC) Grant, University of Dhaka, Bangladesh (Ref. No. Reg/Admin-3/63459).