Degradation Of Synthetic Dyes Research Articles

Green synthesis of biomass-derived carbon quantum dots for photocatalytic degradation of methylene blue.

Water pollution, significantly influenced by the discharge of synthetic dyes from industries, such as textiles, poses a persistent global threat to human health. Among these dyes, methylene blue, particularly prevalent in the textile sector, exacerbates this issue. This study introduces an innovative approach to mitigate water pollution through the synthesis of nanomaterials using biomass-derived carbon quantum dots (CQDs) from grape pomace and watermelon peel. Utilizing the hydrothermal method at temperatures between 80 and 160 °C over periods ranging from 1 to 24 h, CQDs were successfully synthesized. A comprehensive characterization of the CQDs was performed using UV-visible spectroscopy, Fourier-transform infrared spectroscopy, dynamic light scattering, Raman spectroscopy, and luminescence spectroscopy, confirming their high quality. The photocatalytic activity of the CQDs in degrading methylene blue was evaluated under both sunlight and incandescent light irradiation, with measurements taken at 20 min intervals over a 2 h period. The CQDs, with sizes ranging from 1-10 nm, demonstrated notable optical properties, including upconversion and down-conversion luminescence. The results revealed effective photocatalytic degradation of methylene blue under sunlight, highlighting the potential for scalable production of these cost-effective catalytic nanomaterials for synthetic dye degradation.

Synergistic enhancement of photocatalytic efficiency and durability in CoNi-decorated Cu2O/Cu films for superior synthetic dye degradation

The Cu2O/Cu emerges as a promising candidate for photocatalytic application owing to its efficient photon absorption in the visible light spectrum. However, the susceptibility of Cu2O-based photocatalysts to self-decomposition diminishes their effectiveness. This study introduces CoNi as co-catalyst to enhance the durability of Cu2O/Cu photocatalyst. Electrodeposition was employed to decorate the Cu2O/Cu crystal surface with Co, Ni and CoNi. The deposition potential of CoNi was optimized to produce a high-performance photocatalyst. The utilization of CoNi co-catalyst resulted in significant enhancements in photoelectrochemical properties under light irradiation when compared to using a single Co or Ni co-catalyst, suggesting a synergistic effect between Co and Ni within the system. The enhancement is evidenced by a noteworthy increase in the photocurrent of the photocatalyst, rising from 10.24 mA/cm2 to 20.81 mA/cm2. In addition, the decoration of CoNi resulted in a reduction of the charge transfer resistance from 4.2 kΩ to 0.7 kΩ, while simultaneously increasing the electrochemically active surface area of the photocatalyst from 15.49 cm2 to 157.69 cm2. The observed modifications lead to a substantial improvement in the photocatalytic efficiency, resulting in an impressive 88 % degradation of methylene blue, which is 3.4 times higher than achieved in the absence of the co-catalyst. Moreover, there was a significant improvement in the photostability of the photocatalyst, with an increase from 16.81 % to 50.55 %. These findings demonstrate the significance of CoNi co-catalyst decoration in producing a highly active and durable photocatalyst, making it a promising candidate for efficient synthetic dyes degradation.

Nano-architected titania/gold@GO nanosheets for sonocatalytic degradation of azo dyes in textile wastewater

Environmental pollution is creating serious risks to both human health and the atmosphere which has been a major threat on a global scale. Therefore, it is necessary to focus on the evolution of the environment and trace contaminants for effective and reliable detection and degradation methods. Photochemical methods such as Surface-Enhanced Raman Scattering (SERS) and sono-catalytic degradation can be used to accelerate the detection and degradation of toxic dyes. In the present work, a Gold/Titania/Graphene oxide nanocomposite (ATG) was investigated as a capable dual substrate for SERS sensing and sono-catalytic degradation of pollutants. The nanosize distribution (6–12 nm) of ATG was synthesized by a solvothermal route. X-ray diffraction pattern illustrates the anatase phase of the titanium dioxide. Sonocatalytic degradation was aided using Raman spectroscopy. The effectiveness of ATG as a sono-catalytic substrate and SERS sensor was first evaluated using commercial dyes, such as malachite green and Bismarck brown. Furthermore, research has been conducted on the harmful elements in textile effluents (TE). The NN and C-N bands found in the SERS spectra of TE indicates the presence of carcinogenic azo-dye impurities. The enhancement factor was observed to be 5.77×1012 with the limit of detection (LOD) as 6.0×10−12M. Additionally, the sono-catalysis of ATG was evaluated for the elimination of these dye pollutants in TE. Following sono-catalysis by ATG, a high degradation rate constant of approximately 8.44 ×10−3/min was noted in TE with 89 % of degradation efficiency. The enhanced SERS detection, sono-catalytic degradation of synthetic dyes and effluent stem from the combined action of’ plasmonic characteristics of Au NPs, anatase TiO2, and the π-π stacking characteristic of GO.

Boosting Degradation of Synthetic Dye and Pesticide Residues in Water Using NCDs/FeNH2BDC Photocatalysts

Boosting Degradation of Synthetic Dye and Pesticide Residues in Water Using NCDs/FeNH2BDC Photocatalysts

Cu-ZnO/CdS/rGO tertiary heterojunction for improved photocatalytic degradation of synthetic dyes using visible light

A novel tertiary heterojunction based on Cu-ZnO/CdS/rGO was successfully designed and produced from graphite, Zn2+. Cu2+, and Cd2+ precursors. The produced materials underwent thorough characterization, including microstructure, surface charges, chemical groups, elemental composition, as well as optical properties. The Cu-ZnO/CdS/rGO photocatalytic system exhibited a response to visible light, with an Eg = 1.8 eV, leading to a capability of generating efficient charge carriers by visible light irradiation. The combination of Cu-ZnO/CdS/rGO led to a reduction in recombination rate of charge carriers. Various factors such as pH, catalyst load, pollutant concentration, and reaction time, were methodically investigated for their influence on photocatalytic degradation of Direct Blue 71 (DB 71).The developed Cu-ZnO/CdS/rGO heterojunction exhibited a significant improvement in decomposition yield compared to individual components (from 1.26 to 2.0-fold). Under optimal conditions (pH 6.5 and 500 mg/L catalyst load), over 93 % of 0.05 g/L DB 71 were decomposed in just 100 min by visible light catalyzed by Cu-ZnO/CdS/rGO system, and the decomposition process fit the best the pseudo-1st-order kinetics, with coefficients in the range of 0.889 to 0.983. The primary species responsible for DB 71 degradation was the (O2•-), revealing that graphene sheets of reduced graphene oxide (rGO) might play an important role for electron transfer and react with dissolved O2 molecules to generate O2•-. This research introduces an innovative method to develop an efficient and feasible photocatalytic system, offering potential for use in practical wastewater treatment systems dealing with synthetic dye contamination.

Green Synthesis of Mixed ZnO-SnO2 Nanoparticles for Solar-Assisted Degradation of Synthetic Dyes

In this work, ZnO, SnO2, and their mixed ZnO-SnO2(25%) nanoparticles (NPs) were successfully green synthesized in a straightforward manner with a low-cost and environmentally friendly approach using a banana peel extract. The synthesized nanophotocatalysts were characterized using various techniques including FTIR, XRD, UV-Vis, TEM, SEM, BET, PL, EDS, and TGA. The characterization results showed that the ZnO and SnO2 powders were crystallized in a hexagonal wurtzite and rutile-type tetragonal structures, respectively, and their mixed ZnO-SnO2(25%) NPs contain both structures. Also, it was found that the addition of SnO2 into the ZnO structure reduces the PL intensity of the latter, confirming better separation of electron/hole pairs. The average particle size of a ZnO-SnO2(25%) NP photocatalyst was found to be 7.23 nm. The cationic dyes methylene blue (MB) and crystal violet (CV) as well as the anionic dyes naphthol blue black (NBB) and Coomassie brilliant blue R 250 (CBB) were employed as model dyes to assess the dye removal efficiencies of the biosynthesized nanophotocatalysts under sunlight. In all cases, the mixed ZnO-SnO2(25%) NP photocatalyst showed much better photocatalytic activity than individual photocatalysts. The degradation percent of dyes using ZnO-SnO2(25%) NPs ranged between 92.2% and 98%. The efficient photocatalytic activity of ZnO-SnO2(25%) NPs is attributed to the effective charge separation and reduced electron/hole recombination rate. The kinetic study results conformed to a pseudo first-order reaction rationalized in terms of the Langmuir–Hinshelwood model. Furthermore, the results showed that the ZnO-SnO2(25%) NP photocatalyst is highly stable and could be recycled several times without a noticeable reduction in its catalytic activity towards dye removal.

Optimization of laccase from Stenotrophomonas maltophilia E1 by submerge fermentation using coconut husk with its detoxification and biodecolorization ability of synthetic dyes

Enzymatic degradation of synthetic dyes holds an immense promise for addressing the environmental concerns associated with the textile and dye industries. This study aimed to isolate bacteria capable of producing laccase enzymes from an anthropogenic environment. Subsequently, viability of utilizing cost-effective agricultural residues as substrates for laccase production was assessed. Response Surface Methodology (RSM) and the One Variable at a Time (OVAT) approach was pursued for the optimization of laccase production, followed by pH and temperature stability, dye degradation and decolorization experiments, toxicological studies on the degraded dye metabolites. In results, laccase-producing bacterial strain was identified as Stenotrophomonas maltophilia strain E1 (S. maltophilia). Among variety of substrates, coconut husk exhibited optimal efficacy. In a statistical optimization study, it was found that S. maltophilia was capable of producing laccase 51.38 IU/mL, i.e., three times higher than the amount of laccase produced by unoptimized medium (16.7 IU/mL), and the enzyme activity was found to be steady at an acidic pH, and a mesophilic temperature range. The laccase obtained from S. maltophilia E1 demonstrated proficient dye decolorization capabilities, achieving a notable 92.1% reduction in Malachite green dye coloration at a concentration of 500 ppm. Gas chromatography–mass spectrometry (GC–MS) analysis of the decolorized derivatives of Malachite green revealed a conversion into a distinct compounds. Moreover, after undergoing laccase treatment, Malachite green exhibited decreased phytotoxic effects on Oryza sativa, pointing to enzymatic detoxification. Collectively, insights gained from the present study will contribute to the development of efficient enzymatic approaches for addressing the environmental pollution caused by synthetic dyes.Graphical

Photocatalytic and antioxidant potential of silver nanoparticles biosynthesized using Artemisia stelleriana leaf extracts

Abstract The antioxidant and photocatalytic activity of Artemisia stelleriana-based silver nanoparticles (AS-AgNPs) was investigated in this study. Microscopic, X-ray diffraction and spectroscopic studies were used to characterize the synthesized AS-AgNPs. UV–visible spectrophotometric examination revealed a peak at 425 nm. The phytocompounds involved in the transformation of silver ions into AS-AgNPs were confirmed using Fourier-transform infrared spectroscopy analysis. The crystalline nature of the AS-AgNPs was verified using the X-ray powder diffraction technique. Spherical-shaped AS-AgNPs with a size of 22.7 nm were proved using field emission scanning electron microscopy. The AS-AgNPs were top-notch photocatalysts for the degradation of Reactive Blue-222A (RB-222A) and Reactive Blue-220 (RB-220) dyes. After 80 min of UV light exposure, AS-AgNPs degraded RB-222A and RB-220 dyes by 94.6 and 90.8%, respectively. The phytotoxicity investigation in Vigna radiata and Artemia salina indicated that the hazardous dye can be degraded into innocuous chemicals by AS-AgNPs. The results suggest that AS-AgNPs are an excellent antioxidant and photocatalyst for the degradation of synthetic dyes.

Efficient malachite green biodegradation by Pseudomonas plecoglossicide MG2: process optimization, application in bioreactors, and degradation pathway

Microbial degradation of synthetic dyes is considered a promising green dye detoxification, cost-effective and eco-friendly approach. A detailed study on the decolorization and degradation of malachite green dye (MG) using a newly isolated Pseudomonas plecoglossicide MG2 was carried out. Optimization of MG biodegradation by the tested organism was investigated by using a UV–Vis spectrophotometer and the resultant degraded products were analyzed by liquid chromatography–mass spectrometry and FTIR. Also, the cytotoxicity of MG degraded products was studied on a human normal retina cell line. The optimum conditions for the significant maximum decolorization of MG dye (90–93%) by the tested organism were pH 6–7, inoculum size 4–6%, and incubation temperature 30–35 °C, under static and aerobic conditions. The performance of Pseudomonas plecoglossicide MG2 grown culture in the bioreactors using simulated wastewater was assessed. MG degradation (99% at 100 and 150 mg MG/l at an optimal pH) and COD removal (95.95%) by using Pseudomonas plecoglossicide MG2 culture were the best in the tested culture bioreactor in comparison with that in activated sludge or tested culture-activated sludge bioreactors.The FTIR spectrum of the biodegraded MG displayed significant spectral changes, especially in the fingerprint region 1500–500 as well as disappearance of some peaks and appearance of new peaks. Twelve degradation intermediates were identified by LC–MS. They were desmalachite green, didesmalachite green, tetradesmalachite green, 4-(diphenylmethyl)aniline, malachite green carbinol, bis[4-(dimethylamino)phenyl]methanone, [4-(dimethylamino)phenyl][4-(methyl-amino)phenyl]methanone, bis[4-(methylamino)phenyl]methanone, (4-amino- phenyl)[4-(methylamino)phenyl]methanone, bis(4-amino phenyl)methanone, (4-amino phenyl)methanone, and 4-(dimathylamino)benzaldehyde. According to LC–MS and FTIR data, two pathways for MG degradation by using Pseudomonas plecoglossicide MG2 were proposed. MG showed cytotoxicity to human normal retina cell line with LC50 of 28.9 µg/ml and LC90 at 79.7 µg/ml. On the other hand, MG bio-degraded products showed no toxicity to the tested cell line. Finally, this study proved that Pseudomonas plecoglossicide MG2 could be used as an efficient, renewable, eco-friendly, sustainable and cost-effective biotechnology tool for the treatment of dye wastewater effluent.

Isolation and Molecular Identification of Direct Red 80 Synthetic Dye Degradation Bacteria from Palembang Indonesia Jumputan Cloth Industrial Waste

Isolation and Molecular Identification of Direct Red 80 Synthetic Dye Degradation Bacteria from Palembang Indonesia Jumputan Cloth Industrial Waste

Aplikasi Fotokatalis TiO2 Dan Alternatifnya Untuk Degradasi Pewarna Sintesis Dalam Limbah Cair

Liquid waste containing synthetic dyes is a significant environmental problem, particularly in the textile industry, such as batik waste. Recent studies have shown the potential of TiO2 photocatalysis in reducing color and Chemical Oxygen Demand (COD) in such waste. In addition to TiO2, ZnO nanoparticles and ZrO2-TiO2 composites have also been tested as alternative photocatalysts for the degradation of synthetic dyes. The use of immobilized TiO2 nanoparticles on various substrates such as plastic sheets, hydrogels, or hybrid films has increased the efficiency of photocatalytic processes and allowed for the separation of photocatalysts from the waste after treatment. Furthermore, the combination of TiO2 with additives such as Mg, Ag, and Fe has enhanced the photocatalytic performance in removing synthetic dyes from wastewater. The use of TiO2-based photocatalytic membranes also enables simultaneous filtration and degradation of pollutants in wastewater treatment. In addition to degrading synthetic dyes, TiO2 photocatalysis has been successfully used to remove natural dyes like Congo red from industrial wastewater. Recent studies have also explored new synthesis methods to obtain TiO2 photocatalysts with enhanced properties, such as TiO2 nanocoating on nanocomposites or TiO2 nanocoating on porous materials. Overall, these studies demonstrate that TiO2 photocatalysis has great potential in liquid waste treatment, particularly in the degradation of synthetic dyes found in textile industry waste like batik waste.

A Review of Bacterial Degradation of Azo Dyes

Biodegradation of synthetic dyes using different bacteria is becoming an accepted approach for treating Azo dye wastewater to mitigate many environmental problems. Azo dye has a negative impact on the environment by increasing biochemical oxygen demand (B.O.D.) and chemical oxygen demand (C.O.D.). The Biodegradation of azo dyes by different bacteria was evaluated. Biodegradation of synthetic dyes not only results in the decolorization of the dyes but also in the disintegration of the dye molecules into smaller and simpler parts. Decolorization of the dye arises when the chromophoric center of the dye is slashed. Various microorganisms, including fungi, bacteria, yeasts, and algae, have been used to decolorize and Degradation of synthetic dyes. Bacterial decolorization is usually faster than fungal decolourization. It is well known that bacteria degrade azo dyes reductively under anaerobic circumstances to colorless aromatic amines, which are carcinogenic compounds. These colorless aromatic amines must also be degraded because they may be toxic, mutagenic, and carcinogenic to humans and animals Bacteria are capable of removing dyes by adsorption and absorption. Biosorption rates are directly matched with the composition of heteropolysaccharides and the cell wall lipids. Dead cells are more useful in Biosorption than living cells because they do not need nutrients and can be stockpiled for a long time. The azoreductases are considered to be the most potent group of enzymes active in the Biodegradation of synthetic azo dyes. They accomplish the reductive cleavage of synthetic azo dyes bonds. Laccases enzymes become more interesting and have more focus recently due to their ability in generating much lower toxic aromatic amines. Laccases do not need other cofactors. Many factors affecting the process are temperature, pH, salinity, dye concentration, and Bioremediation in aerobic and anaerobic environments. Keywords: Biodegradation, azo dyes, biochemical oxygen demand (B.O.D.), chemical oxygen demand (C.O.D.), bacterial enzymes and Bacterial Laccases enzymes.

Sorghum-grown fungal biocatalysts for synthetic dye degradation

The synthetic dye discharge is responsible for nearly one-fifth of the total water pollution from textile industry, which poses both environmental and public health risks. Herein, a solid substrate inoculated with fungi is proposed as an effective and environmentally friendly approach for catalyzing organic dye degradation. Pleurotus ostreatus was inoculated onto commercially available solid substrates such as sorghum, bran, and husk. Among these, P. ostreatus grown on sorghum (PO-SORG) produced the highest enzyme activity and was further tested for its dye biodegradation ability. Four dye compounds, Reactive Blue 19 (RB-19), Indigo Carmine, Acid Orange 7, and Acid Red 1 were degraded by PO-SORG with removal efficiencies of 93%, 95%, 95%, and 78%, respectively. Under more industrially relevant conditions, PO-SORG successfully degraded dyes in synthetic wastewater and in samples collected from a local textile factory, which reveals its potential for practical usage. Various biotransformation intermediates and end-products were identified for each dye. PO-SORG exhibited high stability even under relatively extreme temperatures and pH conditions. Over 85% removal of RB-19 was achieved after three consecutive batch cycles, demonstrating reusability of this approach. Altogether, PO-SORG demonstrated outstanding reusability and sustainability and offers considerable potential for treating wastewater streams containing synthetic organic dyes.

Photocatalytic Degradation of Synthetic Dyes Using Cyanobacteria-Derived Zinc Oxide Nanoparticles

Photocatalytic Degradation of Synthetic Dyes Using Cyanobacteria-Derived Zinc Oxide Nanoparticles

Biogenic synthesis and characterization of ZnO nanoparticles for degradation of synthetic dyes: A sustainable environmental cleaner approach

Agro-wastes including leaves, manure, plant parts, and vegetables, etc. are usually unusable, therefore discarded in agricultural activities which may lead to different environmental and health issues. This study is focused on the use of agro-waste to synthesize ZnO nanoparticles which are applied for the degradation of two synthetic dyes. Zinc oxide nanoparticles (ZnO-NPs) are synthesized from the fruit peel extract of Citrus limetta (C. limetta). The optimized conditions to synthesize ZnO-NPs were 80 °C temperature, 9 pH, 1:4 reactant ratio and 80 min contact time. ZnO-NPs were characterized by UV–Visible spectroscopy showing a λmax at 350 nm. Scanning Electron Microscopy (SEM) was used to characterize the shape and size of synthesized ZnO nanoparticles. The nanoparticles, size varied from 40 to 42 nm. ZnO-NPs were then applied for the remediation of two dyes Basic Brilliant Flavine Y-40 (dye A), and Direct Fast Rose FR Red 227 (dye B) following the optimization of experimental factors like dye concentration, nanoparticles concentration, pH, H2O2 level and temperature. The synthetic dyes were decolorized 30% at 0.02%, and 49% at 0.04% with dye concentration, 43% at 5 mg and 56% at 4% NPs, 58% and 63% at 7 pH, 71% at 0.4 M, and 76% at 0.5 M H2O2 and 85% and 89% at 50 °C for dye A and dye B. The experimental results exhibited that COD, TOC and toxicity assessments were 74.56 & 73.24% and 92 & 91% for dye A and dye B, respectively. The UV–Visible and FTIR studies also confirmed the degradation of the targeted dyes. The current study suggested a greener approach towards environmental remediation for a neat and clean environment.

Deep Eutectic Solvent-Mediated Synthesis of Ni3V2O8/N-Doped RGO for Visible-Light-Driven H2 Evolution and Simultaneous Degradation of Dyes

Photochemical hydrogen evolution and the degradation of synthetic dyes in water are the two key ways to unravel the issues associated with the energy and environmental sectors for sustainability. The present work deals with the use of a deep eutectic solvent for the synthesis of Ni3V2O8/N-doped reduced graphene oxide (NiV/NR hybrid). The NiV/NR hybrid, NRGO, and NiV were characterized using XRD, SEM, TEM, UV-DRS, XPS, and other photo-electrochemical techniques. The NiV/NR hybrid exhibited high efficiency towards light-driven hydrogen evolution (12,546 µmol)) compared to pristine NiV (6453 µmol) and NRGO (1935 µmol). Among the various sacrificial agents examined, TEOA showed better activity in H2 evolution. The photocatalytic degradation of anionic (Methyl orange; MO) and cationic dyes (crystal violet; CV) were evaluated and the reaction conditions were carefully optimized to attain the utmost efficiency. The efficiency of the NiV/NR hybrid was higher under visible light irradiation than UV light and able to degrade 94.6 and 96.7% of MO and CV, respectively. The results of the simultaneous degradation of dyes and total organic carbon (TOC) removal were good. Based on the obtained bandgap and Mott–Schottky plots, the mechanism of photocatalysis in the NiV/NR hybrid is discussed in detail. The reusability and stability of the NiV/NR hybrid in both H2 evolution experiments and degradation studies are excellent. The fabricated NiV/NR hybrid material could be used for multiple applications in energy and environmental applications.

Ultraviolet-activated clamshell hydroxyapatite-substituted palladium in the photoreduction of methyl orange water pollutant.

This study focuses on the modification of natural hydroxyapatite (HAp) derived from clamshell by impregnation with palladium (Pd) at different pH in wet precipitation method to produce photoactive green materials for the degradation of synthetic dyes. It was found that, at pH 10, Pd has been successfully impregnated into HAp lattice with Ca/P ratio of 1.77 and particle distribution size range of 40-470 nm. The impregnation has resulted in the band gap of Pd/HAp at 3.19 eV, as calculated using Tauc's plot from the UV-Vis spectroscopy data of the Pd/HAp. Next, the photocatalytic activities of Pd/HAp were carried out with methyl oranges (MO) as models of water pollutants under UV irradiation. The photodegradation efficiency of the catalyst reached the optimum value of 41.63%, 48.17%, and 43.64% after 120 min of continuous UV irradiation for pH values 8, 10, and 11.5 of Pd/HAp samples, respectively. This study opens a new paradigm in using naturally derived materials as photocatalysts in the reduction of persistent water pollutants at a low cost and green sustainable approach.

Synthesis and evaluation of Fe-doped zinc oxide photocatalyst for methylene blue and congo red removal

Zinc oxide is one of the most common photocatalysts utilized for the photocatalytic degradation of synthetic dyes aside from titanium dioxide. However, the application of ZnO in the treatment of wastewater containing synthetic dyes is limited due to the high energy band gap which allows ZnO to be efficient upon irradiation with ultraviolet radiation only. This study aims to evaluate the photocatalytic degradation efficiency of the zinc oxide photocatalyst and its derivatives, specifically 0.25, 0.5, 2.5 and 5 mol% Fe(II)-doped ZnO, 0.25, 0.5, 2.5 and 5 mol% Fe(III)-doped ZnO and 2.5 mol% Fe(II)-Fe(III)-doped ZnO. The performance of the photocatalysts was evaluated based on the effect of solution pH, effect of photocatalyst loading and nature of dye. The synthesis of photocatalysts were done using sol-gel synthesis method, and photodegradation tests were carried out under visible light exposure for 60 minutes. The photocatalysts were characterized with SEM, FTIR, and UV-Vis spectroscopy. The optical characterization results show that 2.5 mol% Fe(II)-Fe(III)-doped ZnO has the lowest band gap energy of 3.401 eV which was estimated using Tauc’s plot. This further validated the degradation performance of the 2.5 mol% Fe(II)-Fe(III)-doped ZnO photocatalyst where it displayed the highest photocatalytic degradation efficiencies at all pH and photocatalyst loading. The highest degradation achieved using methylene blue was 94.21% and 32.97% using congo red as model solute at optimum pH and 300 mg/L photocatalyst loading. In overall, the present study has proven that Fe-doped photocatalysts have the potential for the degradation of various synthetic dyes upon irradiation with visible light.

Correction: Synthesis and testing of photocatalytic potential of MgFe2O4/ZnO/perlite magnetic heterojunction for degradation of synthetic dyes

Correction: Synthesis and testing of photocatalytic potential of MgFe2O4/ZnO/perlite magnetic heterojunction for degradation of synthetic dyes

Mn3O4@ZnO Hybrid Material: An Excellent Photocatalyst for the Degradation of Synthetic Dyes including Methylene Blue, Methyl Orange and Malachite Green

In this study, we synthesized hybrid systems based on manganese oxide@zinc oxide (Mn3O4@ZnO), using sol gel and hydrothermal methods. The hybrid materials exhibited hierarchical morphologies and structures characterized by the hexagonal phase of ZnO and the tetragonal phase of Mn3O4. The hybrid materials were tested for degradation of methylene blue (MB), methyl orange (MO), and malachite green (MG) under ultraviolet (UV) light illumination. The aim of this work was to observe the effect of various amounts of Mn3O4 in enhancing the photocatalytic properties of ZnO-based hybrid structures towards the degradation of MB, MO and MG. The ZnO photocatalyst showed better performance with an increasing amount of Mn3O4, and the degradation efficiency for the hybrid material containing the maximum amount of Mn3O4 was found to be 94.59%, 89.99%, and 97.40% for MB, MO and MG, respectively. The improvement in the performance of hybrid materials can be attributed to the high charge separation rate of electron-hole pairs, the co-catalytic role, the large number of catalytic sites, and the synergy for the production of high quantities of oxidizing radicals. The performance obtained from the various Mn3O4@ZnO hybrid materials suggest that Mn3O4 can be considered an effective co-catalyst for a wide range of photocatalytic materials such as titanium dioxide, tin oxide, and carbon-based materials, in developing practical hybrid photocatalysts for the degradation of dyes and for wastewater treatment.