Sonophotocatalytic Degradation of Malachite Green by Nanocrystalline Chitosan-Ascorbic Acid@NiFe2O4 Spinel Ferrite

Abstract

Statistics show that more than 700 thousand tons of dye are produced annually across the globe. Around 10–20% of this is used in industrial processes such as printing and dyeing, while about 50% of the dye produced is discharged into the environment without proper physicochemical treatment. Even trace amounts of dye in water can reduce oxygen solubility and have carcinogenic, mutagenic, and toxic effects on aquatic organisms. Therefore, before dye-containing wastewater is discharged into the environment, it must be properly treated. The present study investigates the green synthesis of nickel ferrite NiFe2O4 (NIFE) spinel magnetic nanoparticles (MNPs) via chemical coprecipitation of a solution of Ni2+/Fe3+ in the presence of a biopolymer blend of chitosan (CT) and ascorbic acid (AS). The magnetic nanomaterial was characterized by Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), scanning electron microscopy–energy dispersive X-ray analysis (SEM-EDX), transmission electron microscopy (TEM), ultraviolet-visible spectroscopy (UV-Vis), differential scanning calorimetry (DSC), and vibrating-sample magnetometry (VSM). The material was further explored as a catalyst for the photocatalytic degradation of malachite green (MG) under visible light irradiation coupled with ultrasonic waves. The combination of 90 min of visible solar light irradiation with 6.35 W·mL−1 ultrasonic power at pH 8 resulted in 99% of the photocatalytic efficiency of chitosan-ascorbic acid@NIFE (CTAS@NIFE) catalyst for 70 mg·L−1 MG. The quenching of the photocatalytic efficiency from 98% to 64% in the presence of isopropyl alcohol (IPA) suggested the involvement of hydroxy (•OH) radicals in the mineralization process of MG. The high regression coefficients (R2) of 0.99 for 35, 55, and 70 mg·L−1 MG indicated the sonophotocatalysis of MG by CTAS@NIFE was best defined by a pseudo first-order kinetic model. The mechanism involves the adsorption of MG on the catalyst surface in the first step and thereby mineralization of the MG by the generated hydroxyl radicals (•OH) under the influence of visible radiation coupled with 6.34 W·mL−1 ultrasonic power. In the present study the application of photodegradation process with sonochemistry results in 99% of MG mineralization without effecting the material structure unlike happens in the case adsorption process. So, the secondary pollution (generally happens in case of adsorption) can be avoided by reusing the spent material for another application instead of disposing it. Thus, the ecofriendly synthesis protocol, ease in design of experimentation like use of solar irradiation instead of electric power lamps, reusability and high efficiency of the material suggested the study to be potentially economical for industrial development at pilot scale towards wastewater remediation.

Recent Progress and Prospects in Catalytic Water Treatment

“…A similar behavior has also been demonstrated for the degradation of Basic Blue 41 over NiFe 2 O 4 /RGO nanocomposite with efficiencies around 97% 1033 and of Malachite Green by nanocrystalline chitosanascorbic acid@NiFe 2 O 4 spinel ferrite. 1034 Composite 3D core−shell urchin-like MoS 2 /carbon photocatalyst allows a large increase of the electrical conductivity of MoS 2 that accelerates the electron transfer efficiency and provides more active sites for the degradation of the pharmaceutical residues in water. 1035 The effect of the pollutant concentration, the initial pH, coexisting anions, peroxymonosulfate dose, and ultrasonic intensity has been demonstrated in a sonophotocatalytic coupling system for levofloxacin degradation under visible light irradiation (Figure 98).…”

Preparation, Characterization of Green Synthesis CeO2 Nanoparticles and Their Photocatalytic Activity towards Malachite Green Dye

“…All of these factors contribute to the value of our findings when compared to other publications. [26,[56][57][58][59][60][61] To detect the reaction mechanism the tertiary-butanol (t-BuOH), 1,4-benzoquinone (BQ), and ammonium oxalate (AO) scavengers were added to explore the role of hydroxyl radicals ( * OH), superoxide radicals (O 2 *À ), and hole (h + ) in the degradation of MG dye. [11,62] Decreasing the photodegradation during the scavenger added, indicating that the radical is in control dye degradation.…”

“…The applied biopolymers blend was responsible not only for produced stable nanoparticles, increased the surface density but also significantly influenced the photocatalytic activity. [26] Current work is gaining attention to valorize the Aloe Vera leaf extract to produce a valuable material like ceria nanoparticles which is an effective and economic photo-catalyst using malachite green dye as an organic pollutant model. In addition, the structure of green ceria nanoparticles was validated in contrast to chemically generated CeO 2 utilising several techniques.…”

Synthesis and Potential Applications of Modified Xanthan Gum

“…Furthermore, the toxicity of MG dye owing to its hazardous effects on the ecosystem, following various diseases. MG color remains for a long time in water and does not readily degrade [117][118][119][120]. Recently, Abu Elella et al [37] reported the fabrication of antibacterial nanocomposite adsorbent based on biodegradable polymers for removal of both MG and pathogenic microorganisms as E.coli and S. aureus as the most common pollutants for water.…”