Effective photocatalytic degradation of sulfamethoxazole using PAN/SrTiO3 nanofibers

Abstract

Freshwater scarcity driven by pollution and climate change necessitates the development of effective water purification methods. There is an urgent need for innovative solutions that can efficiently remove contaminants from water sources. A effective material for the photocatalytic degradation of organic sulfonamide antibiotics from water was developed in this study. A composite of electrospun strontium titanate (SrTiO3) and carbon fibers polyacrylonitrile/strontium titanate (PAN/SrTiO3) was employed for the photocatalytic degradation of sulfamethoxazole (SMX). Scanning Electron Microscopy/Energy Dispersive Spectroscopy (SEM-EDS), Transmission electron microscopy (TEM), X-ray diffraction (XRD), and X-ray photoelectron spectroscopy (XPS) were used to characterise the composite. The fibers had a thickness of ~250 nm and uniformly dispersed PAN and SrTiO3 particles. A PAN/SrTiO3 composite with a 1:1 mass ratio (20 mg) demonstrated excellent performance, achieving over 90 % degradation at pH 7 and a contaminant concentration of 5 mg/L under ultraviolet (UV) light irradiation during 60 min. The composite was tested for the photodegradation of the major organic pollutant (SMX) in distilled and river water. In river water, the degradation efficiency exceeded 80 % at pH 7 because of the formation of secondary radicals involved in antibiotic degradation. SMX degradation was described using a pseudo-first order kinetic equation using the Langmuir-Hinshelwood model. These results underscore the novelty and significance of the PAN/SrTiO3 composite and demonstrate its high efficiency and potential for large-scale water purification applications.