Degradation Of Methyl Orange Dye Research Articles

Theoretical and experimental study of the photodegradation of methyl orange in the presence of different morphologies of Au-ZnO using Monte Carlo dynamic simulation.

Herein, a simple approach was formed based on synthesizing different morphologies of ZnO and Au-ZnO as photocatalyst. In this study, ZnO and Au-ZnO were synthesized via a co-precipitation method and fully characterized via scanning electron microscopy (SEM), X-ray diffraction (XRD), and energy-dispersive X-ray spectroscopy (EDX). Three different ratios of Zn2+:OH- (1:2, 1:3, and 1:5) controlled the morphology of samples, which were made into spindle, star, and flower structures, respectively. Then, the photocatalytic activity was studied and compared. Their comparison showed that the flower morphology for ZnO and Au-ZnO was more effective in photocatalytic degradation and decolorization of methyl orange dye. Also, quantum and Monte Carlo (MC) calculations were carried out to investigate the adsorption of methyl orange (MO) molecules on ZnO(111) surface in the presence of Au or without Au in aqueous conditions by Monte Carlo adsorption locator simulations in the Materials Studio 2017 software. Au created a tendency to form a relatively strong interaction of MO with the ZnO(111) surface. The adsorption of MO on Au-ZnO(111) in the presence of Au was more significant than that of MO on ZnO(111), suggesting Au could significantly improve the reactivity of the methyl orange toward the ZnO(111).

Carbon Quantum Dots (CQDs) Based Composites Photocatalyst for Wastewater Purification

A comparative study of the Carbon Quantum Dots (CQDs) based composites photocatalyst for water purification was carried out. New finding of CQDs and TiO2 have demonstrated significant advantage since it provides environmentally friendly for photocatalytic degradation of methyl orange (MO) dye. CQDS and TiO2 were prepared by using hydrothermal method. The CQDs and CQDS/TiO2 were fully characterized by using transmission electron microscope (TEM) to identify the size range and shape that involve in the adsorption process. The synthesized CQDs and CQDs/TiO2 had small semi spherical morphology with 5 nm in size. The result of photocatalytic activity revealed that there is photocatalytic degradation of MO in the presence of only pure CQDs and CQDs/TiO2 composites which the value of concentration decreased against time. CQDs/TiO2 exhibited higher photocatalytic activity, which indicated that both CQDs and TiO2 played important roles for the high photocatalytic activity under visible light irradiation.

Three Isomeric Zn(II)-Sn(IV)-Zn(II) Porphyrin-Triad-Based Supramolecular Nanoarchitectures for the Morphology-Dependent Photocatalytic Degradation of Methyl Orange.

Three isomeric Zn(II)–Sn(IV)–Zn(II) porphyrin-based triads (T2, T3, and T4) were synthesized by the reaction of common Zn(II) porphyrins (ZnL) with different Sn(IV) porphyrins (SnPn). The Sn(IV) porphyrin precursors differ with respect to the position of the pyridyl-N atoms. All compounds were characterized by 1H NMR, UV–vis, fluorescence spectroscopy, electrospray ionization–mass spectrometry, and field-emission scanning electron microscopy measurements. In these structures, the intramolecular cooperative metal–ligand coordination of the 3-pyridyl nitrogen in SnP3 with axial ZnL and the π–π interactions between the adjacent porphyrin triad are the determining factors affecting the nanostructures of T3. Owing to the geometrical constraints of the SnP2 center, this type of interaction is not possible for T2. Therefore, only the π–π interactions affect the self-assembly process. In the case of SnP4, intermolecular coordinative interactions and then π–π interactions are responsible for the nanostructure of T4. The morphology-dependent photocatalytic degradation of methyl orange (MO) dye in aqueous solution under visible light irradiation was observed for these photocatalysts, and the degradation ratio of MO varied from 76 to 94% within 100 min. Nanorod-shaped T3 exhibited higher performance compared to nanosphere T2 and nanoflake T4.

Synthesis, characterization, and photocatalytic performance of methyl orange in aqueous TiO2 suspension under UV and solar light irradiation

Nano-crystalline titanium dioxide (TiO2) photocatalyst has been extensively utilized in the last few decades because of its strong oxidizing power, redox selectivity, and higher photocatalytic performance. In this work, TiO2 nanoparticle (NPs) was synthesized, characterized, and applied for the degradation of methyl orange (MO) dye in an aqueous solution under UV and solar light irradiations. The XRD results showed dominated anatase phase (82%) with a smaller crystalline size (18.23 nm). A rough surface with a uniform spherical shape was observed by SEM analysis. FTIR and UV–Vis/DRS spectroscopy confirmed the stretching vibration of the hydroxyl groups and higher absorption edge towards longer wavelength with smaller bandgap energy (3.12 eV) of TiO2 lattice structure. The activity of TiO2 NPs was carried out from the degradation of MO dye as a model contaminant for textile effluent in presence of UV/solar irradiation. The photodegradation efficiency of MO dye (15 mg L−1) was observed at 85.90% and 96.38% for 0.150 g and 0.030 g of TiO2 NPs at natural pH (7.0), after 5 h of UV and solar light irradiation. The respective rate constants were determined to be 0.0063 min−1 and 0.01 min−1 for UV and simulated solar light irradiation respectively, and exhibited the best-fitted kinetic model of pseudo-first-order. The photodegradation efficiency was increased with the decrease of pH, while efficiency decreased with an increase in initial dye concentration. The obtained result from TiO2 NPs was compared with commercially available Degussa P25 catalyst. The photocatalyst reusability test and reaction mechanism were also evaluated. The study suggests that TiO2 NPs are a promising photocatalyst that can be used for the degradation of organic dye compounds from textile wastewater towards the sustainable management of environment.

Enhanced photocatalytic activity in ferroelectric BiFeO3 nanoparticles treated by a corona poling method

BiFeO3 particles of about 50 nm were prepared by the sol-gel method with the calcination temperature of 450°C. The corona poling treatment was carried out on BiFeO3 nanoparticles for different electric fields and duration time. XRD analysis reveals that the BiFeO3 nanoparticles maintain the stable perovskite structure before and after the poling treatment. Raman and XRD analysis respectively show that the Bi–O bonds stretched and the lattice distorted for BiFeO3 nanoparticles with corona poling treatment. The poled BiFeO3 nanoparticles exhibit better photocatalytic kinetics in degradation of methyl orange (MO) dyes under the visible light irradiation for 3 h, which is about 5.1 times better relative to the BiFeO3 nanoparticles without the poling treatment. We conjecture that the enhanced internal electric fields produced by the corona poling process may be beneficial to the reduction of the combination of photogenerated electron-hole pairs resulting in the enhanced photocatalytic activity of BiFeO3 nanoparticles.

Photoelectrochemical properties and photocatalytic degradation of methyl orange dye by different ZnO nanostructures

Photoelectrochemical properties and photocatalytic degradation of methyl orange dye by different ZnO nanostructures

Revealing the Effect of MnO2, Activated Carbon and MnO2/Activated Carbon on Chitosan Polymer Host Fabricated Co NPs: Antibacterial Performance and Degradation of Organic Compounds.

MnO2 and MnO2 blended with 1 and 2 weight percent of activated carbon (AC), MnO2/AC1 and MnO2/AC2 were synthesized through the sol–gel method. The pure chitosan (CS) films were cast in the form of films. Similarly, 5 weight% of each MnO2, AC, MnO2/AC1 and MnO2/AC2 was intermingled with the CS to produce different films, such as CS-AC, CS-MnO2, CS-MnO2/AC1 and CS-MnO2/AC2. Zero-valent Co NPs were then supported on these films through the chemical reduction method and expressed as CS@Co, CS-AC@Co, CS-MnO2@Co, CS-MnO2/AC1@Co and CS-MnO2/AC2@Co NPs. All the catalysts were characterized by field emission scanning electron microscopy (FESEM), energy-dispersive spectroscopy (EDS) and X-ray diffraction (XRD) techniques. The synthesized catalysts were used as a dip catalyst against the hydrogenation of 4-nitrophenol (4NP), and for the degradation of methyl orange (MO) and Congo red (CR) dyes. The kapp and R2 values were deduced from pseudo-first-order kinetics for 4NP and MO and zero-order kinetics for CR dye. The kapp values of CS-AC@Co and CS-MnO2/AC1@Co NPs for 4NP hydrogenation were higher than those for any other member of the series, at 1.14 × 10−1 and 1.56 × 10−1 min−1 respectively. Similarly, the rate of CR degradation was highest with CS-AC@Co. The R2 values for 4NP, MO and CR dyes were above 0.9, which indicated that the application of pseudo-first- and zero-order models were appropriate for this study. Furthermore, the antibacterial activity of all the catalysts was evaluated against Pseudomonas aeruginosa and Escherichia coli. The CS-AC@Co NPs exhibited the highest zone of inhibition compared to other catalysts against P. aeruginosa, while all the catalysts were inactive against E. coli. This study reveals that the catalyst can be used for the degradation of other pollutants and for microbial inhibition.

Enhanced Photocatalytic Activity of ZnO Nanorods/(Graphene Oxide, Reduced Graphene Oxide) for Degradation of Methyl Orange Dye

ZnO has been well-known as a significant photocatalyst material due to its high surface area, efficient charge transport, and superior photosensitivity. Even though photocatalysis using bare ZnO NRs is useful in pollutant remediation, two main drawbacks scale down their performance as photocatalysts. First, ZnO NRs absorb mainly the UV light, which compromises a small portion of the solar spectrum, and second, the high recombination rate in the ZnO NRs prevents the path of electron-hole outward and then reduces the photocatalysis efficiency. In this work, ZnO-NRs, ZnO-NRs/Graphene Oxide (GO), and ZnO-NRs/Reduced Graphene Oxide (rGO) array composites were vertically grown on conductive glass substrates of SnO2:F (FTO). The films were synthesized by hydrothermal method using ZnO seed layers deposited by spray pyrolysis technique. The nanosheets of GO and rGO were anchored onto the surface of the as-prepared ZnO-NRs by using the spray deposition technique (SDT). The photocatalytic activity of these materials was studied by analyzing the degradation of methylene orange (MO) in an aqueous solution under ultraviolet light, and we found that the decoration of ZnO-NRs with nanosheets of GO and rGO resulted in a significant enhancement of the photocatalytic degradation efficiency, where ZnO-NRs/rGO are more efficient than ZnO-NRs/GO and the latter better than pure ZnO-NRs.

Biosynthesis of Gold Nanoparticles (AuNPs) with Dimrit Raisin Extract and Their Degradation Activity for Water Contaminants

AuNPs are being conventionally synthesized by traditional methods (physical and/or chemical) with preferred and well-defined morphology, size and shape. On the other hand, it has been reported that these methods involve difficult reaction conditions and/or toxic chemicals. In this study, an easy, cost effective and more environmentally and biological-friendly method was described for the synthesis of gold nanoparticles with Dimrit raisin extract for the first time. The effects of some experimental parameters, such as concentrations of both raisin extracts and Au solutions, synthesis time and synthesis temperature were investigated for the synthesis of AuNPs. The synthesized AuNPs were extensively characterized by UV-Visible spectrometer, Transmission electron microscopy (TEM), X-ray diffraction patterns (XRD) and Fourier transform–infrared spectroscopy (FTIR). TEM results show spherical along with triangular and hexagonal shaped nanoparticles with an average size of 15 nm. Large amounts of toxic dyes are used in the different industrial area and dyes posed a threat for water sources. Therefore, it has become imperative to develop inexpensive and environmentally friendly methods to remove dyes from water. In recent years, degradation using green synthesized nanoparticles has become an efficient method to remove dyes from the water sources. In this study, the catalytic activity of the AuNPs for the degradation of both methylene blue (MB) and methyl orange (MO) dyes were also studied and AuNPs behaved as effective catalysts for both degradations of MB and MO dyes in terms of percentage removal and kinetics. The experiment results showed that AuNPs can be employed as strong candidate in wastewater treatment studies.

Comparative Study of Fe,N-TiO<sub>2</sub> Photocatalysts under UV Light Irradiation

Titanium dioxide (TiO2) has been acknowledged as a promising photocatalyst in environmental remediation including wastewater treatment. In this study, TiO2 nanoparticles co-doped with iron (Fe) and nitrogen (N) was synthesized via sol-gel method and subsequently followed by calcination process at 300 °C, 500 °C and 700 °C for 3 hours. The prime objective of this study is to investigate an effect of different calcination temperatures in enhancing the photocatalytic activity of synthesized TiO2 which was evaluated through the degradation of methyl orange (MO) dye. The structure and properties of the prepared samples were studied by X-Ray Diffraction (XRD), Energy Dispersive X-Ray Spectroscopy (EDX), Field Emission-Scanning Electron Microscope (FE-SEM) and Ultraviolet-Visible Spectrophotometer (UV-Vis). The results obtained from XRD showed the presence of anatase phase in all samples at 300 °C and 500 °C. Further increase of calcination temperature up to 700 °C, mixed-phase of anatase and rutile formed. XRD results also suggest that the addition of impurities has a great effect on the crystallinity and particle size of TiO2. The obvious agglomeration phenomena existed in the annealed samples with nanometer size, as observed in FESEM images. The photocatalytic performance under UV light shows that co-doped Fe, N-TiO2 at 500 °C indicated highest MO degraded of 96.5 % within 3 hours of irradiation time. From the current finding, Fe,N-TiO2 possessed the potential to be commercialized as a photocatalyst in wastewater remediation especially in treating dye pollution.

Photocatalytic Degradation of Methyl Orange Dye with Synthesized Chitosan/Fe2O3Nanocomposite and its Isotherm Studies

: Background: The study focuses on the synthesis of chitosan/Fe2O3 nanocomposite, its characterization and application in methyl orange dye degradation. Methods: The synthesized chitosan/ Fe2O3 nanocomposite was characterized with Powder X-Ray Diffraction, Fourier Transfor-­‐ mation Infrared Spectroscopy (FTIR), Transmission Electron Microscopy (TEM) and UV-­‐Vis Spectroscopy. Results: The characterization showed that the Fe2O3nanoparticles were embedded in the polymer matrix of chitosan. The size of the Fe2O3nanoparticles was less than 10nm and the crystallite size was 1.22 nm. The synthesized chitosan/Fe2O3nanocomposite was tested for methyl orange degradation using different parameters such as the effect of contact time, effect of dose, effect of concentration and effect of pH for the degradation of methyl orange dye in aqueous solution. The Fruendlich, Langmuir and Temkin isotherm studies were also conducted for adsorption of methyl orange on Chitosan/Fe2O3nanocomposite. Conclusion: The study indicated that the synthesized chitosan/Fe2O3 nanocomposite had the potential of degrading methyl orange dye up to 75.04% under the set condition in this experiment, which indicates that Chitosan/Fe2O3 nanocomposite is a viable option that can be used for the degradation of methyl orange dye.

Synthesis of MnCoO/CNT nanoflakes for the photocatalytic degradation of methyl orange dye and the evaluation of their activity against Culex pipiens larvae in the purification of fresh water.

Researchers worldwide have been looking forward to using novel ways to purify fresh water containing pollutants and disease vectors. In the current work, nanoparticles were introduced as a promising technique for cleaning water and saving human health and living organisms. The nanocomposites, MnCoO and MnCoO/CNTs, were fabricated by a cost-effective co-precipitation method. Phase and molecular structures were investigated by XRD and Raman spectroscopy. The samples exhibited polycrystalline nature of binary phase and weak crystallinity. The elemental composition was recorded by EDX spectra, revealing the purity of the nanoparticles. The surface morphology and particle distribution were described using SEM and TEM micrographs, indicating that MnCoO/CNTs are nanoflakes with a large surface area. The optical parameters include α, E g, n, k, which were identified from T% and R% measurements, suggesting that MnCoO has a direct band gap that reduced with the CNT support. The photocatalytic activity of MnCoO/CNTs was examined for the degradation of methyl orange dye with an efficiency of ∼90.97% over 0.6 g L-1 within 50 min under UV irradiation. In the larvicidal activity, the micrograph images revealed the impact of the nanoflake particles on the 4th instar larvae, where the enzymatic activity of esterases acetylcholinesterase, α- and β-carboxylesterase, and transaminases drastically decreased with the MnCoO/CNT ratio.

Characterization of Fabricated Gold‐Doped ZnO Nanospheres and Their Use as a Photocatalyst in the Degradation of DR‐31 Dye

Water contamination is a significant issue in the modern day, caused by the textile dying business, and it has a detrimental impact on living organisms. We report on the manufacture of gold‐doped ZnO nanospheres using a simple heat treatment approach and the use of ZnO nanoparticles as photocatalysts for the degradation of methyl orange dye. To increase this degrading activity, Au was utilised as a modifier, and their temperature quenching effect was noticed. One of the most efficient electron grabbers in the conduction band is Au ion. The novelty of this recent research is that it has found that anatase to rutile phase transformation is promoted, and the highest transformation was achieved by using 1.0% of Au, which proves Au‐doped ZnO‐based nanoparticles are best for this degradation of dyes. The structural, morphological, optical, electrical, and photocatalytic characteristics of the synthesised nanocatalysts were determined. These nanoparticles have a grain size of 45‐75 nm. Photocatalytic activity was investigated using UV‐Vis spectra, and a significant absorption peak of about 482 nm was discovered. With increasing frequency, the dielectric constant and frequency of the produced nanoparticles drop. The kinetic analysis yields a rate constant of 0.0165 min-1 for nanosphere‐like particles. At a concentration of 1% Au, the produced nanoparticles degrade the dye completely in 150 minutes when exposed to UV light.

Photocatalytic Efficiency of Hybrid Titanium Dioxide Nanowires/Reduced Graphene Oxide (TiO2NWs/RGO) for Degradation of Methyl Orange Dye

The aim of this research is to improve the photocatalytic efficiency by implementation of titanium dioxide nanowires/reduced graphene oxide (TiO2NWs/RGO) hybrid photocatalyst for dye degradation. The hybrid photocatalyst TiO2NWs/RGO was prepared using fabrication method. The physico-chemical properties of the photocatalyst was investigated by FTIR, XRD, SEM TGA, BET and their photocatalytic efficiency was evaluated for methyl orange degradation. Almost 100% of methyl orange was degraded by TiO2NWs/RGO hybrid photocatalyst under UV light within 210 min using 1.0 g at initial concentration of methyl orange were 10 and 20 ppm. This is due to the 1D/2D heterostructures of TiO2NWs/RGO hybrid photocatalyst that leads to the larger surface area, unique morphological and crystallinity properties, as well as excellent mobility of charge carriers and thermally stable structure

Solvothermally synthesized oxygen-deficient SnO2 for the degradation of methyl orange dye under sunlight and LED light irradiation

A simple solvothermal method was used to efficiently synthesize rutile SnO2 nanoparticles with crystallite sizes ranging from 7 to 10 nm. The morphological observations revealed that the microparticles were formed by the aggregation of spherical nanoparticles, which were confirmed from SEM and TEM analysis. Also, the HRTEM analysis demonstrated that the nanoparticles observed by SEM and TEM are not single crystalline but rather composed of randomly oriented nanoparticles ranging in size from 3 to 5 nm. The EDS and XPS confirmed the presence of Sn and O; no other impurities were found. UV–vis study shows that the band gap value for SnO2 nanoparticles varies from 2.76 and 3.16 eV. The SnO2 nanoparticles are attributed to band edge emission, interstitial defect and homogeneous oxygen vacancies, as per the PL study measured at ambient temperature. The S1 sample was red-shifted compared to other samples, with a having surface area of about 45.2 m2/g, large pore size (5.82 nm) and large pore volume (0.081 cm3/g). That helps to achieve > 99 and 97 % decomposition of MO within 6 and 25 min under sunlight and 9 W LED light irradiation, respectively. The scavenger test suggests that h+ radicals play a vital role in the photodegradation of MO dye.

The synergistic effect of acid-etched g-C3N4 nanosheets and polyaniline nanofibers for the adsorption and photocatalytic degradation of textile dyes: a study of charge transfer mechanism and intermediate products

Acid-etched graphitic carbon nitride (TGCN) nanosheets decorated with polyaniline (PANI) nanofibers for the adsorption and photocatalytic degradation of Methyl Orange (MO) and Congo Red (CR) toxic textile dyes.

Enhanced photocatalytic activities of a hierarchical ZnO/V2C MXene hybrid with a close coupling heterojunction for the degradation of methyl orange, phenol and methylene blue dye

A hierarchical ZnO/V2C MXene hybrid exhibited enhanced photocatalytic performance due to its close coupling heterojunction facilitating photo-generated carrier transfer.

A Coronopus didymus based eco-benign synthesis of Titanium dioxide nanoparticles (TiO2 NPs) with enhanced photocatalytic and biomedical applications

Clean water is a global challenge and several conventional procedures are accompanied with a number of drawbacks. As a result, new materials and methods must be introduced to address the issue of water purification. The current study presents a green as well as facile approach for synthesizing TiO2 NPs using leaf extract Coronopus didymus for the first time, which could be used as a photocatalysts. Different microscopic and spectroscopic techniques including UV–Vis, FT-IR, XRD, HRTEM, DLS, BET, SEM, SAED and EDX were used to confirm the formation, size, shape, and crystalline structure of the biosynthesized TiO2 NPs. The as synthesized TiO2 NPs were examined for the photocatalytic degradation of methyl orange (MO) and methylene blue (MB) dyes. The results showed that biogenic TiO2 NPs exhibited remarkable photocatalytic degradation efficiency towards MO (95%) and MB (90%) only in 30 min of irradiations respectively. The biomediated TiO2 NPs were also screened for bacterial inhibition efficiency against S. aureus and E. coli bacteria. The cytotoxicity study revealed that TiO2 NPs are nontoxic to ordinary healthy RBCs. These exceptional antibacterial and photocatalytic activities may be due to their nanosize and wide ranging surface area of TiO2 NPs.

Synthesis and effective performance of Photocatalytic and Antimicrobial activities of Bauhinia tomentosa Linn plants using of gold nanoparticles

The present work deals with the plant-based gold nanoparticles (Au NPs) synthesis from the leaf extract of Bauhinia tomentosa Linn. The physicochemical properties of synthesized Au NPs were characterized by using various analytical techniques. The PXRD & SAED pattern results were confirmed the high purity of the face centered cubic structure of Au NPs. FT-IR showed that Au NPs contain chemical functional groups of combined precursors materials like amine group (-NH2), carbonyl group, –OH groups etc. The FE-SEM & TEM results show that the NPs have spherical morphology with an average diameter size is 15 nm and large surface area was obtained. Utilize to the photocatalytic activity of synthesized Au NP are investigate to their ability of degraded organic dye of methyl orange (MO) under sunlight irradiation and these NPs show enhanced photocatalytic activity of degrading the dye within a few hours of exposure. Further, these synthesized Au NPs were subjected into the antimicrobial assay (Mueller–Hinton Agar testing) using agar disc diffusion method using the microorganism Gram-negative Escherichia coli (E. coli) and Gram-positive Staphylococcus aureus (S. aureus). And then we predict that the synthesized materials have a high photo degradation of MO dye with visible light and better responses for their antimicrobial activity of Au nanoparticles.

Electrochemical Degradation of Synthetic Textile Wastewater by C/MnO2 Electrode Assessed by Surface Response Methodology

The current work investigated the optimization of synthetic textile wastewater (STW) containing methyl orange, crystal violet, and neutral red reactive dye degradation on manganese dioxide coated on graphite electrode using the Box-Behnken design (BBD). Carbon coated by manganese oxide (C/ MnO2 ) electrode was prepared by the sol-gel method. Graphite substrates were obtained from spent lithium-ion batteries for recycling and reducing the price of the electrode material in electrochemical processes. C/MnO2 was used as anode and cathode in an electrochemical cell during experiments. In addition, BBD was applied to design the experiments and find the optimal conditions for the degradation of STW. From the proposed model, the rate of the removal efficiency of chemical oxygen demand (COD) reached 83.63% with the optimum conditions (6.989 hours, concentration of 1.5 g/L NaCl, and current density of 50 mA/cm2 ). Based on the obtained optimum values, the specific energy consumption was around 30.359 kWh (kg COD)-1. Furthermore, the C/MnO2 electrode was characterized by Raman spectroscopy, and MnO2 films were prepared from the sol-gel process and deposited on graphite. Thus, using graphite coated with manganese dioxide, indirect anodic oxidation (IAO) can be efficient for the removal of the organic matter from the real textile dye bath.