Zinc Oxide/Iron Oxide Nanocomposites for Photodegradation and Adsorption of Pollutants in Water

Abstract

The presence of different pollutants in water bodieshas increased over the years with population and industrial activity growth. This phenomenon produces a deterioration in water quality. In this context, improved, low-cost, and green strategies toremediate water from different sources are currently mandatory.This paper deals with the evaluation of three synthetic pathways toobtain nanocomposites (NCs) based on zinc oxide (Z) and ironoxide (M) nanoparticles. An exhaustive characterization wasperformed on the three NCs achieved. X-ray diffraction andFourier transform infrared data determined that synthetic method3 did not lead to NC formation. The synthetic pathwaysdetermined the NC structure, as is demonstrated by thetransmission electron microscopy and scanning electron microscopy data from MZ1 and MZ2, respectively. Eg values between2.3 and 2.9 eV were achieved, suggesting the formation of a heterojunction structure. Superparamagnetic behavior was confirmed forMZ1 and MZ2, giving magnetizations of saturation of 51.3 and 64.0 emu/gFe, respectively. Because the aim was to design materialsable to function by dual adsorption−photodegradation mechanisms, their performance was evaluated from batch assays usingammonium as a model of an inorganic pollutant and methylene blue (MB) as an organic one. The adsorption of ammonium waseffective and reached efficiencies of 48.5% for MZ1 and 53.1% for MZ2. The maximum efficiency in MB photodegradation (98%)was reached using MZ2. Antibacterial properties were also assayed, finding satisfactory responses against Escherichia coli and Bacillusthuringiensis for both NCs. The data collected within this work positioned MZ materials as suitable tools to remediate sewage, whichmostly contains the group of pollutants evaluated in this paper.