Synthesis of CuFe2O4-Ti and CuFe2O4-Ti-GO nanocomposite photocatalysts using green-synthesized CuFe2O4: determination of photocatalytic activity, bacteria inactivation and antibiotic degradation potentials under visible light

Abstract

BACKGROUND Advanced oxidation processes (AOPs), specifically photocatalysis have gained an essential attraction in the field of micro pollutants degradation. Synthesis and use of proper photocatalysts for target pollutant and water matrix scenarios constitute the primary field of research. In this study, hydrothermal and sol-gel synthesis methods were applied for the synthesis of nanocomposites in the form of spinel ferrite CuFe2O4 (CF) nanocomposites and CuFe2O4-Ti (CFT) and CuFe2O4-Ti-GO (CFT-GO) heterojunction nanocomposites with magnetic properties. And prior to photocatalytic activity based screening, bacteria inactivation and antibiotic degradation potentials of optimum NCs were determined under visible light conditions. PEG and Cydonia oblonga seed extract were used as chemical and bio-chemical reducing-stabilizing agents throughout the hydrothermal synthesis step. The as produced NCs were characterized by XRD, SEM, EDX, BET Surface, FTIR, RAMAN, Photoluminescence and Diffuse Reflectance Spectroscopy analysis. RESULTS According to the pre-screening findings based on the methylene blue removal efficiencies of NCs under UV-vis, CFT %1(w/w) have provided >70% removal at the end of 120 min. While CFT-GO NCs yielded 30% removal rates (Pseudo first order kinetic constants of 0.012 and 0.0036 min(-1) respectively). The reactive oxygen species formation by CFT-GO NC photocatalysts was hindered as a result of conjugation mechanism between MB and aromatic regions of GO and due to high adsorption capacity of the NC. Based on photocatalytic bacteria inactivation findings of the pre-screened NCs; >99% of bacteria were inactivated following 90 min of photocatalytic oxidation by CFT-GO 3%. According to the Modified HOM model, k(2) values were estimated to be 1.36 and 1.93 for CFT 1% and CFT-GO 3% NCs, while no initial and post delay of bacteria inactivation was observed for the latter. Optimum photocatalyst dose was examined (to be 0.6 g L-1) based on photocatalytic degradation of sulfamethoxazole antibiotic at varying initial concentration ([C](0 SMX) = 10 and 2.5 mg L-1). The CFT 1% photocatalysts have provided >89 % SMX degradation level (for [C](0 SMX) = 2.5 g L-1). For the case of mixture of antibiotics [C](0 total) = 2.5 g L-1, CFT 1% have provided >99.5%, >90%, >90% and 28% photocatalytic degradation levels at the end of 180 min for SMX AMP, TET and CLRT antibiotics respectively, while the total rate of degradation was 77%. CONCLUSION By using the green synthesis procedure, copper ferrite nanocomposites (CF) was successfully fabricated with comparable physical and chemical properties. This study not only reports on the green synthesis of common p-type spinel CuFe2O4 but also offer new design of photocatalysts capable of providing efficient removal of antibiotics and bacteria inactivation under visible-light irradiation. (c) 2022 Society of Chemical Industry (SCI).