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This research investigates a novel nanocomposite material composed of reduced graphene oxide (rGO) and nickel-5,15-bisdodecylporphyrin (Ni-BDP) nanoparticles for the effective removal of methyl orange (MO), a harmful synthetic dye, from water. The structure and composition of the synthesized rGO/Ni-BDP nanocomposite were characterized using high-resolution transmission electron microscopy (HR-TEM), Raman spectroscopy, nuclear magnetic resonance (NMR) spectroscopy, mass spectrometry, and ultraviolet-visible (UV-Vis) spectroscopy. The study demonstrates the material's efficacy as both a catalyst and adsorbent for MO removal. Optimal performance was observed at pH 3.0, where the positively charged nanocomposite surface facilitated strong interactions with negatively charged MO molecules, leading to enhanced photocatalytic activity. Under these conditions, 0.01 g of the nanocomposite achieved an impressive 86.2% MO removal efficiency. Furthermore, the study explored the reusability of the rGO/Ni-BDP nanocomposite in repeated cycles of photocatalytic MO degradation under visible light irradiation. While exhibiting some decrease in efficiency over five cycles, the nanocomposite maintained a respectable degradation rate even after multiple uses. Finally, the antimicrobial properties of the nanocomposite were evaluated against both Gram-negative (Escherichia coli) and Gram-positive (Staphylococcus aureus) bacteria exhibiting a zone of inhibition measuring 23 mm and 26, respectively. The minimum inhibitory concentration (MIC) values of 2.50 µg/ml and 1.25 µg/ml for Escherichia coli and Staphylococcus aureus, respectively. The results revealed significant antibacterial activity, demonstrating the broad-spectrum efficacy of the rGO/Ni-BDP nanocomposite. This research underscores the potential of the rGO/Ni-BDP nanocomposite as a versatile material for environmental remediation and antibacterial applications. [ABSTRACT FROM AUTHOR]

In this present study, phytotoxicity of high strength distillery industry discharge wastewater and methyl orange dye in aqueous solution that treated by chemically modified fungal biomass Penicillium on Arachis hypogaea was investigated. The biomass of Penicillium strain was subjected to a simple eco-friendly acid treatment which brought about highly stable, structurally modified fungal biomass (CMFBM). CMFBM thus obtained was evaluated for wastewater treatment efficacy of high strength distillery industry discharge wastewater by determination of various pollutants level. Results of this study revealed that CMFBM treatment exhibited notable removal of pollutants. Batch adsorption studies were carried out to demonstrate the adsorption efficacy of methyl orange dye in an aqueous solution. Studies reveal that CMFCB exhibited high adsorption efficacy, and the rate of adsorption was affected by dosage and time. Phytotoxicity studies reveal that the CMFBM-treated industry wastewater discharge and dye in aqueous solution was not shown any phytotoxic effect on groundnut. No impact on seedlings emergence, growth parameters like shoot length, new branches emerged, total foliage density, total chlorophyll content, and enzymatic antioxidants profile clearly demonstrate the non-target effect of CMFBM-treated industry discharged wastewater and methyl orange dye in aqueous solution. The present investigation would propose the possible utilization of CMFBM in wastewater treatment process and irrigation. [ABSTRACT FROM AUTHOR]

AbstractMethyl orange is one of the most commonly used acidic/anionic dyes, and its removal from wastewater is imperative to ensure environmental sustainability. This study developed a novel cationic CQDs/AM/DMC hydrogel using acrylamide (AM) and methylacryloxyethyl trimethyl ammonium chloride (DMC) as main materials, incorporating carbon quantum dots (CQDs). The hydrogel was comprehensively characterized for morphological features, chemical composition and fluorescence characteristics using FTIR, TEM, SEM, PL and XRD analyses. Moreover, as an adsorbent, the hydrogel effectively removed methyl orange (MO) dye from aqueous solutions. Notably, the CQDs/AM/DMC hydrogel exhibited a maximum adsorption capacity of 298.93 mg/g within 30 min, surpassing that of AM/DMC hydrogel (268.29 mg/g within 50 min) in 50 mg/L MO solution. The Langmuir isotherm and pseudo-second-order models had the best agreement with the experimental data, highlighting monolayer and chemical adsorption as the predominant mechanism governing dye uptake. This study contributes valuable insights into the development of an efficient adsorbent for the removal of hazardous materials from wastewater. [ABSTRACT FROM AUTHOR]

In this study, biocompatible magnesium oxide (MgO) nanostructures were synthesized using an aqueous solution of Piper betle leaf methanolic extract. The color change during the synthesis process, i.e., colorless to dark brown solution, indicates the formation of MgO nano structures which is further confirmed through UV–Visible spectrum that exhibited characteristic absorption band at 329 nm. Results obtained from morphological analysis reveal that MgO nano flakes (MgO NFs) are present as triangular and polyhedral shapes having an average size ranging between 150 and 200 nm with clear lattice fringes. Secondary metabolites were clearly identified from the FTIR spectrum, and they helped in reduction and stabilization during the synthesis of MgO NFs. The XRD pattern displayed Braggs planes of (111), (220), (220), (311), and (222) with a face centered cubic (FCC) structure, which was further confirmed from the SAED pattern using HRTEM analysis. The as-synthesized MgO NFs manifested profound antimicrobial activity against gram positive as well as gram-negative bacteria with favorable biocompatibility. Furthermore, methylene orange dye was degraded almost completely (98.36 %) in the presence of MgO NFs photo catalysts within 1 h of sunlight illumination. In addition, MgO NFs displayed high level of antioxidant properties with recorded IC 50 value of 15.89 μg/ml. [ABSTRACT FROM AUTHOR]

A modified loess/chitosan composite (ML@CS) was prepared via solution. The microstructure and physicochemical properties of ML@CS were characterised via scanning electron microscope (SEM), Zeta potential, X-ray diffraction (XRD), Fourier transform infrared spectrum (FT-IR), and thermogravimetric analysis (TGA). An aqueous solution of methyl orange (MO) was used as simulated wastewater from which the influence of the initial concentration and pH of MO, the dosage amount and regeneration performance of ML@CS, adsorption temperature, and time on the adsorption effect of MO were systematically investigated. The adsorption kinetics, isothermal adsorption, and adsorption mechanism were also analysed. The results indicate that ML@CS had a good adsorption effect on MO. When the initial concentration of MO was 200 mg/L, pH was 5.0, and ML@CS dosage was 1.0 g/L, the adsorption equilibrium could be reached within 180 min at room temperature, and the equilibrium adsorption capacity and removal rate reached 199.52 mg/g and 99.75%, respectively. After five adsorption–desorption cycles, the MO removal rate remained above 82%. The adsorption behaviour of ML@CS for MO conforms to the pseudo–second–order kinetic model and the Langmuir isotherm adsorption model. The spontaneous exothermic process was mainly controlled by monolayer chemical adsorption and the physical adsorption only played an auxiliary role. ML@CS efficiently adsorbed MO in water and can be used as a high-efficiency, low-cost adsorbent for printing and dyeing wastewater treatment. [ABSTRACT FROM AUTHOR]

Ensuring clean water sources is pivotal for sustainable development and the well-being of communities worldwide. This study represents a pioneering effort in water purification, exploring an innovative approach utilizing modified reduced graphene oxide (rGO) aerogels. These advanced materials promise to revolutionize environmental remediation efforts, specifically removing organic contaminants from aqueous solutions. The study investigates the exceptional adsorption properties of rGO-aerogel, enhanced with cysteamine, to understand its efficacy in addressing water pollution challenges. The characterization methods utilized encompass various analytical techniques, including FE-SEM, BET, FTIR, TGA, DSC, XPS, NMR, and elemental analysis. These analyses provide valuable insights into the material's structural modifications and surface chemistry. The research comprehensively explores the intricacies of adsorption kinetics, equilibrium, and isothermal study to unravel the underlying mechanisms governing contaminant removal. MO and Ni2+ exhibited adsorption of 542.6 and 150.6 mg g−1, respectively, at 25 °C. Ni2+ has unveiled the highest removal at pH 5, and MO has shown high removal in a wide pH range (pH 4–7). Both contaminants have shown fast adsorption kinetic performance on an rGO-aerogel surface. This study aims to identify the synergistic effect of cysteamine and rGO in aerogel formation to remove heavy metals and organic contaminants. These findings mark a significant stride in advancing sustainable water-treatment methods and pioneering in synthesizing innovative materials with versatile applications in environmental contexts, offering a potential solution to the global water pollution crisis. [ABSTRACT FROM AUTHOR]

Divalent metal ions co-doped nickel ferrites, MxMʹyNi1−x−yFe2O4 (x = 0.00, 0.03, and 0.05; y = 0.00, 0.03, and 0.05; M = Ca, Zn, and Mʹ = Mg, Mn), synthesis was proceeded through co-precipitation method. The characterization of prepared samples was conducted through XRD (particle size—6.16 to 20.5 nm), VSM (magnetic properties), FTIR (functional groups), FESEM–EDX (surface morphology–elemental composition), UV–visible (band gap energy), and XPS (binding energy) techniques. The synthesized samples were assessed by methyl orange (MO) dye's degradation under sunlight in batch mode. Dye removal percentage varies directly with photocatalyst dosage as well as contact time and inversely with dye's initial concentration at neutral pH. The co-doped nickel ferrite possesses higher dye removal percentage (81.65%) than pure nickel ferrite nanoparticles (70%). The photocatalyst degradation of dye is confirmed with liquid chromatography–mass spectrometry study through various intermediate products. The MO dye's degradation over prepared nanoparticles followed nonlinear pseudo-second-order with R2 = 0.97267 and the Freundlich model with R2 = 0.99744 and has qmax of 22.24 mg g−1 at ambient temperature. After use, the collection of prepared samples was done using an external magnetic field and their reusability makes them a potential material for environmental remediation. [ABSTRACT FROM AUTHOR]

Copyright of Paint & Coatings Industry (0253-4312) is the property of Paint & Coatings Industry Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The present work demonstrates a low-cost, single-step route for synthesizing ZnO, CuO, and ZnO–CuO nanomaterials using oxalic acid as a precipitating agent, avoiding using other surfactants. The current research also demonstrates the chemical reduction method for incorporating Ag nanoparticles onto the surface of the synthesized metal oxide nanostructures using sodium borohydride as the reductant. X-ray diffraction studies reveal the phase purity and crystallinity of the nanoparticles, while X-ray Photoelectron Spectroscopy characterizes the chemical states of surface elements. UV–vis spectra of the samples disclose the modifications shaped by Ag nanoparticles in the absorption characteristics and energy band gap of ZnO, CuO, and ZnO–CuO nanomaterials. The catalytic potentials of the synthesized materials are tested by monitoring degradation reactions of hazardous organic pollutants, including methylene blue and methyl orange, within a few minutes. The significant finding of the present study emphasizes the incorporation of Ag nanoparticles to ZnO–CuO nanocomposite and the use of sodium borohydride in photocatalysis effectively to enhance the rates of degradation of pollutant dyes without the use of intense radiation or unique lamps by initiating a three-stage electron transfer mechanism. [ABSTRACT FROM AUTHOR]

In this study, Zn-Al-SO42− LDH-functionalized biochar was fabricated using the co-precipitation method. The biochar was synthesized from waste cow dung using a low-temperature pyrolysis process (300 °C). The materials were fully characterized by TGA, FTIR, EDS, SEM, and XRD analysis. Then, a comparative study was performed to investigate the adsorption capacity of the materials against an anionic dye (i.e., methyl orange (MO)). The LDH-functionalized biochar demonstrated high adsorption capacity (400 mg/g in 120 min, at pH 5) compared to the raw biochar (212 mg/g in 120 min, at pH 5). The effect of various adsorption parameters (e.g., pH of the dye solution, temperature, initial concentration, adsorbent dosage, and contact time) was investigated. The adsorption of MO on LDH-functionalized biochar followed the Freundlich isotherm and pseudo-second-order kinetics, while the raw biochar followed the Langmuir isotherm and pseudo-second-order kinetics. The thermodynamic data indicated the endothermic nature of adsorption and an increase in the degree of randomness during adsorption. The enhanced adsorption capacity of the Zn-Al LDH-functionalized char was attributed to the synergistic effect of the surface adsorption into the porous biochar matrix, interlayer adsorption, and ion exchange capacity of the LDHs. Therefore, modification of waste cow dung–derived biochar with Zn-Al LDH can be a promising approach to fabricate a highly efficient adsorbent for toxic dyes from wastewater. [ABSTRACT FROM AUTHOR]

TiO2 used for photocatalytic water purification is most active in the form of nanoparticles (NP), but their use is fraught with difficulties in separation from solution or/and a tendency to agglomerate. The novel materials designed in this work circumvent these problems by immobilizing TiO2 NPs on the surface of exfoliated clay minerals. A series of TiO2/clay mineral composites were obtained using five different clay components: the Na-, CTA-, or H-form of montmorillonite (Mt) and Na- or CTA-form of laponite (Lap). The TiO2 component was prepared using the inverse microemulsion method. The composites were characterized with X-ray diffraction, scanning/transmission electron microscopy/energy dispersive X-ray spectroscopy, FTIR spectroscopy, thermal analysis, and N2 adsorption–desorption isotherms. It was shown that upon composite synthesis, the Mt interlayer became filled by a mixture of CTA+ and hydronium ions, regardless of the nature of the parent clay, while the structure of Lap underwent partial destruction. The composites displayed high specific surface area and uniform mesoporosity determined by the size of the TiO2 nanoparticles. The best textural parameters were shown by composites containing clay components whose structure was partially destroyed; for instance, Ti/CTA-Lap had a specific surface area of 420 m2g−1 and a pore volume of 0.653 cm3g−1. The materials were tested in the photodegradation of methyl orange and humic acid upon UV irradiation. The photocatalytic activity could be correlated with the development of textural properties. In both reactions, the performance of the most photoactive composites surpassed that of the reference commercial P25 titania. [ABSTRACT FROM AUTHOR]

Nanometer polymer microspheres have unique physical and chemical properties that make them valuable functional materials for various applications, such as photonic crystal engineering, wastewater treatment, catalysis, environmental protection, sensor technology, drug delivery systems, and smart biomimetic materials. These versatile microspheres have great potential for further development. With the development of novel polymerization techniques, different types of nanometer polymer microspheres have been synthesized and more and more attention has been paid to their potential applications. In this study, nanometer polymer microspheres containing biphenyl formaldehyde were synthesized by Schiff base reaction. We used Tri(4-aminophenyl)amine and 4,4'-biphenyldicarboxaldehyde as reactants, a mixture of 1 : 4 DMF and ethanol as solvent, glacial acetic acid as catalyst, and reflux heating to obtain nanometer-polymer microspheres. We also evaluated the adsorption performance of these microspheres using methyl orange as a simulated pollutant. We conducted a single factor experiment to investigate the effects of different ratios, dosages, times, and temperatures on adsorption efficiency. We characterized the nanometer-polymer microspheres by XRD, IR, and SEM techniques to examine their size, morphology, and structure. Experimental results showed that the optimal ratio for nanometer-polymer microspheres was 1 : 2, with an optimal dose of 25 mg. The optimal adsorption conditions were a temperature of 30°C and a time of 60 min. Since the pH of the solution ranged from 3 to 8, the zeta potentials of microspheres had a negative value. Meanwhile, zeta potentials became more negative as pH increased. The adsorption equilibrium data fit well with the Freundlich model. The microspheres had a stable and uniform rigid structure and good regeneration performance, with regeneration efficiency higher than 80% after five adsorption-desorption cycles. [ABSTRACT FROM AUTHOR]

This study synthesized NiAl-layered double hydroxide (LDH)/Cu-MOF photocatalyst using a simple impregnation method involving NiAl-LDH and Cu-MOF. The successful synthesis was confirmed through Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), scanning electron microscopy (SEM), zeta potential measurements, thermogravimetric analysis (TGA), ultraviolet diffuse reflectance spectroscopy (UV-DRS), N2 adsorption at −196 °C, and electrochemical impedance spectroscopy (EIS). Photocatalysts based on NiAl-LDH, Cu-MOF, and NiAl-LDH/Cu-MOF were used to remove methyl orange (MO) dye from contaminated water. The impact of various factors, including pH, dye concentration, and photocatalyst amount, on MO degradation efficiency was assessed. FTIR analysis was conducted both before and after dye degradation. The optimal degradation conditions were a photocatalyst dose of 25 mg and a pH of 3. Kinetic studies indicated that the degradation of MO dye onto NiAl-LDH/Cu-MOF followed a pseudo-first-order and an L–H or Langmuir–Hinshelwood model. The value of R2 = 0.94 confirms the validity of pseudo-first-order and Langmuir–Hinshelwood (L–H) kinetic models for the photocatalytic degradation of MO dye. This study highlights the importance of developing novel photocatalysts with improved degradation efficiency to protect the water environment. Antibacterial activity was also performed with antibacterial sensibility testing by disk diffusion to determine minimal inhibitory and bactericidal concentrations. In short, NiAl-LDH/Cu-MOF can be helpful for various biomedical and industrial applications. [ABSTRACT FROM AUTHOR]

Nanoparticles of titanium dioxide (TiO2) were made by reacting graphene oxide (GO) with Lawsonia inermis leaf extract. X‐ray diffraction (XRD) analysis revealed crystalline TiO2 doped GO nanoparticles composed of a variety of anatase phases. Initially, UV–vis spectroscopy was performed to confirm the biogenesis of TiO2 doped GO nanoparticles (NP's). Using SEM, the research showed that the biosynthesized TiO2 nanoparticles were mostly spherical, polydispersed, and of a nanoscale size. Because of the energy dispersive X‐ray spectroscopy (EDS) pattern, distinct and robust peaks of titanium (Ti) and oxygen (O) were observed, which were supportive of the formation of TiO2 nanoparticles. By using fourier transform infrared (FTIR) spectroscopy, it was demonstrated that terpenoids, flavonoids, and proteins are involved in the biosynthesis and production of TiO2 doped GO nanoparticles. 2,2‐diphenylpicrylhydrazyl (DPPH) assays were conducted to evaluate the free radical scavenging activity of TiO2 doped GO nanoparticles. Additionally, the TiO2 doped GO NPs had enhanced antioxidant activity when compared with the TiO2 matrix. A series of pure TiO2 and TiO2 doped GO nanoparticles (5, 10, 50, and 100 mg/mL) solutions were investigated for their antibacterial activities. In the current study, zebrafish embryos exposed to pure TiO2 and TiO2 doped GO nanoparticles were toxic and suffered a low survival rate based on concentration. During photocatalysis, O2˙ and ˙OH radicals are rapidly produced because of the reactive species trapping experiment. It was estimated that pure TiO2 nanoparticles and those doped with GO were 80% effective in degrading methyl orange(MO) after 120 min, respectively. Research Highlights: The UV–vis absorption spectra showed a maximum absorbance peak at 290 nm.SEM, the pure TiO2 doped GO NPs exhibit agglomeration and spherical shape.When tested in zebrafish embryos, TiO2 NPs are toxic at high concentrations.GO nanoparticles showed better antioxidant activity.NPs exhibited concentration dependent antioxidative activity. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Materials Engineering / Cailiao Gongcheng is the property of Journal of Materials Engineering Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Green synthesis of iron oxide nanoparticles using plant extracts is of tremendous interest owing to its cost effectiveness, ecofriendly and high efficiency compared to physical and chemical approaches. In the current study, we describe a green approach for producing iron oxide nanoparticles utilizing Polyalthia korintii aqueous leaf extract (PINPs). The prepared PINPs were assessed of their biological and dye degradation potentials. The physico-chemical characterization of PINPs using UV–Visible spectrophotometer, Fourier Transform Infrared Spectroscopy, X-Ray Diffraction studies, Field emission Scanning Electron Microscopy and Energy Dispersive X-ray spectroscopy analysis confirmed the synthesized sample comprised of iron oxide entity, predominantly spherical with the size range of 40–60 nm. Total Phenolic Content of PINPs is 59.36 ± 1.64 µg GAE/mg. The PINPs exhibited 89.78 ± 0.07% DPPH free radical scavenging and 28.7 ± 0.21% ABTS cation scavenging activities. The antibacterial activities were tested against different gram-positive and gram-negative bacteria and PINPs were more effective against Enterococcus faecalis and Klebsiella pneumoniae. Cytotoxicity of PINPs against K562 and HCT116 were measured and IC50 values were found to be 84.99 ± 4.3 µg/ml and 79.70 ± 6.2 µg/ml for 48 h respectively. The selective toxicity of PINPs was demonstrated by their lowest activity on lymphocytes, HEK293 cells, and erythrocytes. The toxicity (LC 50 values) against first, second, third and fourth instar larvae of Culex quinquefasciatus was 40 ± 1.5 mg/mL, 45 ± 0.8 mg/mL, 99 ± 2.1 mg/mL and 120 ± 3.5 mg/mL respectively. Finally, PINPs were utilized to as a catalyst for removal of textile dyes like Methylene blue and methyl orange in a fenton-like reaction. The results showed 100% dye degradation efficiency in a fenton like reaction within 35 min. Thus, the green synthesized PINPs exhibit antioxidant, antibacterial, antiproliferative, larvicidal and dye degradation potentials, indicating their suitability for biological and environmental applications. [ABSTRACT FROM AUTHOR]

Thin films of silver-doped zinc oxide (SZO) were deposited at room temperature using a DC reactive magnetron co-sputtering technique using two independent Zn and Ag targets. The crystallographic structure, chemical composition and surface morphology of SZO films with different silver concentrations were correlated with the photocatalytic (PC) properties. The crystallization of the SZO films was made using millisecond range flash-lamp-annealing (FLA) treatments. FLA induces significant structural ordering of the wurtzite structure and an in-depth redistribution of silver, resulting in the formation of silver agglomerates. The wurtzite ZnO structure is observed for silver contents below 10 at.% where Ag is partially incorporated into the oxide matrix, inducing a decrease in the optical band-gap. Regardless of the silver content, all the as-grown SZO films do not exhibit any significant PC activity. The best PC response is achieved for samples with a relatively low Ag content (2–5 at.%) after FLA treatment. The enhanced PC activity of SZO upon FLA can be attributed to structural ordering and the effective band-gap narrowing through the combination of silver doping and the plasmonic effect caused by the formation of Ag clusters. [ABSTRACT FROM AUTHOR]

Nanoribbons (NRs), leveraging the flexibility of one-dimensional materials and the expansive surface area of two-dimensional materials, offer heightened exposure to edge sites and superior charge transfer rates. Consequently, they present promising prospects within the domain of photocatalysis. Crystalline red phosphorus (cRP), dcharacterized by its layered and fibrous structure, lends itself readily to the production of nanoribbons. Our study demonstrates a robust method for achieving high-yield, high-quality cRP by concurrently introducing mineralizing agent I2 and Si wafers into the Chemical Vapor Transport (CVT) synthesis process. Through ultrasound assistance, we transformed high-quality cRP into crystalline red phosphorus nanoribbons (cRP NRs) with an average thickness ranging from 7.5 to 17.5 nm and an average width between 75 and 175 nm. cRP NRs (I2 and Si) showcased impressive degradation capabilities towards Methyl Orange (MO) and Tetracycline (TC), achieving a remarkable 99% degradation of MO within 18 min under the simulated visible-light irradiation. The reactive species capturing experiments confirmed that ·O2− was the primary active agent responsible for the photocatalytic degradation of MO. [ABSTRACT FROM AUTHOR]

The RuO2/TiO2 composite catalyst was prepared by wet immersion method combined with heat treatment process, and its structure was characterized by X-ray diffraction （XRD） and scanning electron microscopy（SEM）. Analyze the photocatalytic effect of the composite catalyst under different conditions such as the amount of RuO2 solution, light intensity, pH of methyl orange solution, and ventilation rate. The results showed that the doping of RuO2 did not significantly change the crystal plane structure of TiO2. As the mass fraction of RuO2 increased, the sample particle size first increased and then decreased, reaching an ideal equilibrium point at a 0. 15% addition amount. When the amount of RuO2 solution is 0. 15% mass fraction and the light intensity is 4. 23 mW/cm2, the degradation rate of methyl orange reaches 65%, indicating a high photocatalytic effect. When the methyl orange solution is acidic, a more ideal photocatalytic effect can be achieved. When preparing the composite catalyst, the photocatalytic effect is better when the calcination temperature is 550 ℃. However, ventilation is not the key factor affecting the photocatalytic effect. It aims to provide valuable references for the preparation and application of RuO2/TiO2 composite catalysts [ABSTRACT FROM AUTHOR]

Tryptophan(Trp) is being explored as a potential biomarker for various diseases associated with decreased tryptophan levels; however, metabolomic methods are expensive and time-consuming and require extensive sample analysis, making them urgently needed for trace detection. To exploit the properties of Ti3C2 MXenes a rational porous methyl orange (MO)-delaminated Ti3C2 MXene was prepared via a facile mixing process for the electrocatalytic oxidation of Trp. The hollow-like 3D structure with a more open structure and the synergistic effect of MO and conductive Ti3C2 MXene enhanced its electrochemical catalytic capability toward Trp biosensing. More importantly, MO can stabilize Ti3C2 MXene nanosheets through noncovalent π–π interactions and hydrogen bonding. Compared with covalent attachment, these non-covalent interactions preserve the electronic conductivity of the Ti3C2 MXene nanosheets. Finally, the addition of MO-derived nitrogen (N) and sulfur (S) atoms to Ti3C2 MXene enhanced the electronegativity and improved its affinity for specific molecules, resulting in high-performance electrocatalytic activity. The proposed biosensor exhibited a wide linear response in concentration ranges of 0.01–0.3 µM and 0.5–120 µM, with a low detection limit of 15 nM for tryptophan detection, and high anti-interference ability in complex media of human urine and egg white matrices. The exceptional abilities of the MO/Ti3C2 nanocatalyst make it a promising electrode material for the detection of important biomolecules. [ABSTRACT FROM AUTHOR]

In this research, the efficiency of Midyat stone modified with sulphuric acid (H2SO4) in the removal of Methyl Orange (MO) from wastewater is evaluated. Various factors such as contact time, initial MO concentration, and adsorbent dosage were investigated to understand their influence on adsorption efficiency. The optimal conditions for MO removal were as follows: initial concentration 300 mg/L, contact time 70 min, adsorbent dosage 0.5 g. The surface properties of modified Midyat stone (MMS) were investigated using methods such as Fourier transform infrared spectroscopy (FT-IR) and Brunauer, Emmett, and Teller (BET). According to the findings, the isotherm data agreed with the Langmuir isotherm model, indicating both chemical sorption and irreversibility potential. The adsorption capacity of MO at 298, 308 and 318 K was calculated to be 50.02, 54.05 and 58.48 mg/g, respectively. In addition, adsorption kinetics data supported the pseudo-second-order (PSO) kinetic model for MO removal. The research identified MMS as a capable and adaptable substance for capturing MO ions from the aqueous environment due to its significant removal capacity, easy availability, and cost-effectiveness. [ABSTRACT FROM AUTHOR]

In this study, we prepared a low-cost novel Cu/Cu2O/BC nanocomposite visible-light photocatalyst by the impregnation method using CuSO4·5H2O and rice husk biochar (BC) as raw materials and Na2S2O4 as a single reductant to improve the stability and dispersion of the Cu/Cu2O nanoparticles, in order to solve their aggregation tendency during photocatalysis. The morphology and structure of the Cu/Cu2O/BC were characterized using various analytical and spectroscopic techniques. The photocatalytic effect and cyclic stability of the synthesized photocatalyst on methyl orange (MO) removal were investigated under visible light radiation and various parameter conditions, including the mass ratio of BC to Cu/Cu2O, initial MO concentration, pH, temperature, and catalyst dosage. The results show that the synthesized Cu/Cu2O/BC nanocomposite composed of Cu/Cu2O spherical particles was loaded on the BC carrier, which has better stability and dispersion. The best adsorption–photocatalytic effect of the Cu/Cu2O/BC is exhibited when the mass ratio of BC to Cu/Cu2O is 0.2. A total of 100 mg of Cu/Cu2O/BC can remove 95% of the MO and 88.26% of the COD in the aqueous solution at pH = 6, T = 25 °C, and an initial MO concentration of 100 mg/L. After five cycles of degradation, the MO degradation rate in the sample can still remain at 78.41%. Both the quasi-secondary kinetic model and the Langmuir isothermal adsorption model describe the adsorption process. Additionally, the thermodynamic analysis demonstrates that the photocatalytic process follows the quasi-primary kinetic model and that the removal process is of spontaneous heat absorption. The photocatalyst described in this paper offers a cost-effective, easily prepared, and visible-light-responsive solution for water pollution treatment. [ABSTRACT FROM AUTHOR]

Organic dyes are stable and persistent toxic compounds in the aquatic environment that are refractory to decompose by removal methods such as physico-chemical, optical and biological. Their presence in the aquatic media threatens human and wildlife. Herein, ZnO nanoparticles (NPs) due to good chemical durability, low cost and good photocatalytic performance was anchored on biochar (ZnO@biochar) nanocomposites were synthesized towards activation of peroxymonosulfate (PMS) for the photocatalytic removal of methyl orange (MO) dye. Several methods were used to characterization of the nanocomposites including FESEM, XRD, PL, EDS, FT-IR spectroscopy, and N2 adsorption/desorption. The results of the techniques demonstrated that the well-dispersed ZnO NPs were loaded onto the biochar surface. According to the particle size distribution graph, the average particle size of 64 nm was obtained for the ZnO NPs. BET analyzes showed that pore volume, the specific surface area (SSA) and average pore size of the synthesized nanocomposite increased. The survey of effective operational parameters indicated that the highest photocatalytic activity for MO removal was in the pH 3 of solution, 5 ppm initial dye concentration, 30 mg ZnO/biochar nanocomposite, and 20 mg PMS dose under LED-50W lamp irradiation (97.03% in the reaction time of 80 min). During the process, the reduction of the total organic carbon (TOC) contents and chemical oxygen demand (COD) were observed. Moreover, the MO degradation kinetics under optimal operating conditions were determined. It is concluded that the ZnO@biochar nanocomposite/PMS process was an efficient degradation method for the decomposition of the dye pollutant. [ABSTRACT FROM AUTHOR]

This study explores the valorization of tea leaf waste by extracting polyphenols through reflux extraction, subsequently using them to synthesize zero-valent iron nanoparticles (nZVI). The in situ generated nanoparticles, when combined with fixed amounts of hydrogen peroxide, facilitated the removal of various dyes (methylene blue, methyl orange, and orange G) via a hetero-catalytic Fenton process. The iron nanoparticles were thoroughly characterized by gas adsorption of N2 at 77 K, scanning electron microscopy (SEM), Transmission Electron Microscopy (TEM), FT-IR spectroscopy, X-ray diffraction (XRD), and thermal analysis, including thermogravimetric analysis (TG) and temperature-programmed reduction (TPR). A statistical design of experiments and response surface methodology were employed to analyze the influence of polyphenol, Fe(III), and H2O2 concentrations on dye removal efficiency. The results demonstrated that optimizing the operational conditions could achieve 100% dye removal efficiency. This study highlights the potential of nZVI synthesized through eco-friendly methods as a promising solution for water decontamination involving diverse model dyes, thus contributing to sustainable waste management and environmental protection. [ABSTRACT FROM AUTHOR]

1D/2D g-C3N5/g-C3N4 heterojunction photocatalysts were prepared by a direct thermal polymerization method using melamine and 3-amino-1，2，4-triazole as raw materials. The crystal form， chemical composition， morphology and photoelectric chemical properties of the photocatalytic materials were characterized by XRD， XPS， SEM. Photocatalytic activity of 1D/2D g-C3N5/g-C3N4 heterojunction photocatalyst was studied using methyl orange（MO）as target pollutant and 500 W xenon lamp as visible light source. The active substances of the system were studied by active substance capture experiment and ESR characterization. The results show that the disordered stacking of one-dimensional g-C3N5 nanorods and two-dimensional g-C3N4 nanosheets increases the number of active sites. The formation of Z-scheme heterojunction between g-C3N5 and g-C3N4 improves the absorption intensity and spectral range of visible light， and inhibits the recombination of photoelectrons and holes. The superposition of π-π * conjugated systems similar to g-C3N5 and g-C3N4 reduces the mass transfer resistance of charge transfer and improves its photocatalytic activity. Under visible light irradiation for 30 min， 20 mg of 1D/2D g-C3N5/g-C3N4 photocatalytic material almost completely degraded 50 mL of 10 mg/L MO solution， and the apparent rate constant is 0.14836 min-1. After 5 cycles， the photocatalytic degradation rate of 1D/2D g-C3N5/g-C3N4 photocatalytic material for MO is 92.2%， indicating its good stability. The capture experiment of active substances and ESR characterization show that the main active substances in the photocatalytic degradation of MO system by g-C3N5/g-C3N4 photocatalyst are •O2- and h+， and the photocatalytic degradation of MO was a complex bond breaking and oxidation process.

Fingerprint powder remains one of the most effective techniques for identifying individuals from their latent fingerprints. Visualizing latent fingerprints requires powder with high color contrast and strong adhesive to be easily applied on various substrates. The utilization of silica gel extracted from local materials of Lapindo volcanic mud can be applied for fluorescent fingerprint powder based on methyl orange. The powder was synthesized by the sol-gel method, followed by the impregnation of methyl orange as a dye with varying loads. The powders exhibit an amorphous structure and nanoparticle size with an average particle diameter of 80.93 nm by spherical morphology interconnected to form agglomerations. The powder contains silanol, siloxane, azo, and carboxylate functional groups derived from its precursors. The dusting method proves the performance of fluorescent fingerprint powder on porous and non-porous substrates hereafter observed under white light and UV light. The powder containing 0.05 gs of methyl orange per gram of silica gel is the most effective in revealing fingerprint patterns on non-porous surfaces. It has mesoporous properties with a specific surface area of 7.95 m2g−1 and a pore diameter of 23.14 nm. SiMO retained its full capability after two years of storage, indicating it is a great choice for forensic investigations.

Abstract In this research, the use of a three-component nanocomposite of graphene oxide-methyl methacrylate and copper(II) oxide (PMMA-GO-CuO) was investigated. The aim of synthesizing this nanocomposite is to removal dye pollutants, specifically methylene blue (MB) and methyl orange (MO), which are commonly used in dyeing industries, through adsorption. The study focuses on creating GO-CuO and PMMA-GO-CuO nanocomposites as effective adsorbents. A simple and quick method led to the development of the PMMA-GO-CuO nanocomposite, which shows enhanced physical and chemical properties. Key materials include graphene oxide, methyl methacrylate, and copper(II) oxide nanoparticles. Characterization techniques such as FT-IR, XRD, SEM, and TGA were used to analyze the nanocomposite. Results indicate that dye adsorption is more effective at lower pH levels, suggesting that the PMMA-GO-CuO nanocomposite can efficiently remove dyes from industrial wastewater. The experimental data showed that the Langmuir isotherm model accurately represented the equilibrium adsorption, with maximum capacities of 285.71 mg g−1 for methylene blue and 256.41 mg g−1 for methyl orange, indicating a single layer of adsorption. The kinetics followed a pseudo-second order model, suggesting that the adsorption process involves chemical bonding. Additionally, thermodynamic parameters (ΔG°, ΔH°, and ΔS°) indicated that the adsorption is spontaneous. The adsorption mechanism involves hydrogen bonding, π-π interactions, and electrostatic interactions. This study investigates how factors like pH, temperature, contact time, and dye concentration affect the adsorption of methyl orange and methylene blue dyes. A PMMA-GO-CuO nanocomposite was used, achieving 84% removal of MB and 35% removal of MO from industrial wastewater. This study highlights the promising potential of PMMA-GO-CuO nanocomposite as an effective material for the removal of dye pollutants from industrial wastewater. The results showed that the graphene oxide in the composite is effective for removing cationic dyes due to its negative charge. Further research will focus on the optimization of the synthesis process with the aim of achieving competitive performance of this nanocomposite on a large scale. These findings not only advance the field of nanocomposite materials but also provide a practical solution to an important environmental issue, demonstrating the innovation of the present study in the literature.

Magnetic iron oxide (Fe3O4) nanoparticles, iron oxide chitosan (Fe3O4-CS) and iron oxide alginate (Fe3O4-AT) nanocomposite beads were synthesised using green synthesis method. They were used as both adsorbents for the adsorption of methyl orange (MO) dye from the wastewater and heterogeneous catalysts for the catalytic wet peroxidation (CWPO) of MO. While the dye removal was successfully performed with Fe3O4NPs, Fe3O4-CS and Fe3O4-AT in both adsorption studies and CWPO, the highest removal efficiency (99%) in the shortest time (8 min for adsorption, 20 min for CPWO) was obtained with Fe3O4-CS for MO removal. The adsorption experiments were performed with the batch techniques at different contact time, pH, initial dye concentration, temperature, amount of adsorbent and foreign ion effect parameters by Fe3O4-CS adsorbent. The equilibrium was quickly reached after 30 min at pH 3 and 298 K. Fitting equilibrium data to Langmuir, Temkin and Freundlich isotherms showed that Langmuir model was more suitable to describe MO adsorption with a maximum monolayer adsorption capacity of 132 mg/g at 298 K. The Experimental data were analysed using intra particle diffusion, pseudo-first-order and pseudo-second-order kinetic models and it was found that the adsorption kinetics followed a pseudo-second-order equation. Based on thermodynamic studies, adsorption process occurred as spontaneous and exothermic. The effects of the amount of catalyst, pH, temperature and H2O2 concentration were investigated to determine their catalytic activities for the decomposition of MO with CWPO technique. The reusability of Fe3O4-CS for both adsorption and CWPO techniques for MO removal was performed, and the adsorption and oxidation efficiency was found to be 97%. Moreover, the reaction kinetics was also investigated and the oxidation reaction was in good agreement with the pseudo-first order kinetic model. The activation energy (Ea) of the reaction was found to be 10.72 kJ/mol. [ABSTRACT FROM AUTHOR]

In this work, chitosan, a biopolymer was cross-linked using glutaraldehyde (Gl) and modified by natural apatite. The Cs-Gl@Fap composite was used to adsorb methyl orange from an aqueous solution. The materials were characterised by SEM-EDX, FTIR, XRD and TGA-DTG analysis confirming the successful synthesis of Cs-Gl@Fap. The effects of experimental variables on adsorption efficiency were examined. Adsorption studies showed that the maximum adsorption capacity was 225.55 mg/g at an equilibration time of 120 min. The pseudo-second-order rate expression supported data best, while the Langmuir equation could satisfactorily describe isotherm data. The thermodynamic constants of the adsorption process were evaluated. The results showed that the stabilisation by contact of methyl orange on Cs-Gl@Fap was endothermic and spontaneous. Additionally, when reused, the hybrid adsorbent remains at approximately 83% of its original capacity after five adsorption cycles. [ABSTRACT FROM AUTHOR]

ZnO nanorods were synthesized by using the seeds technique. The seeds were synthesized by the low-cost synthesis technique, the Chemical Bath Deposition (CBD) method. Further, CBD and solvothermal methods used these seeds in the next deposition to coating. The XRD results confirm the formation of the ZnO hexagonal phase. FESEM high magnification images confirm the formation of hexagonal-shaped nanorods for Samples 1 and 3 and for Sample 2 mixed nanostructures of disk-like nanoparticles and nanorods were observed. Further, these nanorods were used as the catalytic material under the halogen lamp to study dye degradation. Samples 1 and 3 show degradation up to 55% and 68%, whereas Sample 3 showed a higher catalytic rate which degraded methyl orange 90% dye in 40 min. The enhancement in catalytic activity is explained by structural, morphological, and optical properties. The deposition using the seeds technique enhanced the degradation efficiency. Highlights: We synthesized the ZnO nanostructure using seed technique. The degradation of methyl orange was studied and maximum degradation was 90% in 40 min. Mixed morphology was observed for hydrothermal synthesis method. [ABSTRACT FROM AUTHOR]

In order to reduce the environment pollution caused by waste tea and increase its high added value. In this paper, waste tea was used as raw material and waste tea-based porous carbon was prepared by chemical activation with waste tea as raw material. The tea-based porous carbon were characterized by scanning electron microscope, X-ray diffraction and nitrogen adsorption/desorption. The adsorption performance of methyl orange (MO) in wastewater was studied and the isothermal adsorption model and kinetic model of tea-based porous carbon on MO were further analyzed. The results showed that the tea-based porous carbon had rich pore structure and the specific surface area of porous carbon HPC-NaOH reached 3 026 m2/g with a microporous surface area of 2 811 m2/g and the total pore volume of 1.54 m3/g. With the initial concentration of MO of 200 mg/L and a dosage of 1.5 g/L, the maximum adsorption capacity of porous carbon HPC-NaOH was 1 264.66 mg/g and the removal rate of MO was as high as 94.85%. the adsorption process of porous carbon HPC-NaOH for MO was conformed to Langmuir model and the pseudo-second-order kinetic equation, indicating that the adsorption process belonged to the chemical adsorption of a single molecular layer.

Abstract With a rapid increase in industrial growth around the world, the demand for an entirely novel category of nanoparticles and technologies for wastewater treatment has become a key concern for environmental protection. Recently, hybrids of layered double hydroxides (LDH), particularly those containing LDH, have gained attention as potential nanoscale adsorbents for water treatment. Recent research has shown that LDH-containing composites are interesting versatile materials with the ability to be used in energy storage, photocatalysis, nanocomposites, and water treatment. In the current work, LDH-containing composites were utilized as adsorbents for the purpose of purifying water. The adsorbents investigated are Zn–Co–Fe/LDH/Chitosan-in situ sample preparation (LDH/CS1) and Zn–Co–Fe/LDH/Chitosan-ex situ sample preparation (LDH/CS2). Furthermore, LDH/CS1 and LDH/CS2 were investigated for wastewater treatment from methyl orange dye (MO) with various adsorption conditions. When the initial MO concentration was 20 mg/L and the amount of adsorbent was 0.1 g, the removal efficiency reached 72.8 and 91.7% for LDH/CS1 and LDH/CS2, respectively. The MO’s maximum adsorption capabilities are 160.78 and 165.89 mg/g for LDH/CS1 and LDH/CS2, respectively, which is much greater than that of comparable commercial adsorbents. MO adsorption onto LDH/CS1 and LDH/CS2 was best characterized by the pseudo-second-order kinetic model. The equilibrium adsorption data was followed by the Freundlich and Langmuir models. The adsorption is favorable as evidenced by the equilibrium parameter R L values for MO adsorption onto LDH/CS1 and LDH/CS2, which were 0.227 and 0.144, respectively. Using the free volume distribution method and the positron annihilation lifetime technique, the nanostructure of the materials was examined.

Abstract In the current paper, a NiO nanoparticles-loaded mesoporous carbon (CMK-3) catalyst, denoted as NiO/CMK-3, has been successfully synthesized using a facile strategy. The as-prepared material has been characterized through XRD, Raman spectroscopy, low-temperature N2 physisorption measurements, FTIR, FE-SEM, TEM, and XPS. The as-fabricated NiO/CMK-3 catalyst manifested a superior activity in the NaBH4-assisted reduction of methylene blue (MB) dye to its colorless leuco form. Remarkably, over 99% of 25 mg L−1 MB was reduced by 7.5 mM/L NaBH4 using 0.1 g L−1 NiO/CMK-3 within 3 min at room temperature. Furthermore, the kinetics study confirmed the appropriateness of the pseudo-first-order kinetic model for elucidating the kinetics of MB reduction by the catalyst. Importantly, the NiO/CMK-3 catalyst maintained almost constant catalytic activity even after 5 times of reuse in MB reduction, demonstrating its superior stability and reusable ability. So, NiO/CMK-5 appears as a promising heterogeneous catalyst for the effective remediation of dye-containing wastewater.

Pillarization of bentonites (from East Java) with ZnO semiconductors has been synthesized using co-precipitation methods into a ZnO/Bentonite composite and applied as a catalyst in a photocatalytic process to remove Methyl Orange (MO) dyes. The optimum pH condition of MO dyes is at pH 2 with a degradation rate of 22.91% (from 15 mg/L to 11.523 mg/L). The optimum ZnO/Bentonite catalyst weight condition is 200 mg, with a degradation rate of 29.11% (from 15 mg/L to 10.596 mg/L). The optimum time condition for UV lamp irradiation is 60 minutes, with a degradation rate of 64.92% (from 15 mg/L to 5.244 mg/L). The kinetics of MO photocatalytic reaction using ZnO/Bentonite catalyst follows the pseudo-first-order Langmuir Hinshelwood-Santosa kinetic model with photocatalytic reaction rate constant (k1) of 0.014 and photocatalytic equilibrium constant (K) of 0.012.

Abstract In the modern era, with the rapid growth of various industries, the issues of energy crisis and environmental pollution have garnered increasing attention. One significant source of industrial pollution is printing and dyeing wastewater. This wastewater often contains dyes that have aromatic structures and azo groups, such as Methyl orange (MO), which are both toxic and difficult to degrade. If these dyes are released into the wastewater stream without any treatment, they can have adverse effects on ecological balance and human health. Therefore, it is crucial to identify suitable treatment strategies to efficiently remove dyes from wastewater systems before discharge. In this study, the Methyl orange (MO) azo dye has been removed from dyes-contaminated wastewater, for the first time, using a novel amino-ethyl carboxymethyl cellulose crosslinked ampholyte hydrogel (AECMC). Different characterization methods, including FTIR, TGA, and DSC were used to characterize the generated AECMC compounds. The water absorption and cationic exchange capacities were assessed. Factors affecting the MO anions adsorption including MO concentration, adsorption pH, temperature, time, adsorbent dose, and agitation speed have been investigated. Moreover, the kinetics of the adsorption process was assessed by the use of three models: pseudo-first-order, Pseudo-second-order, and Elovich. Moreover, the mechanism of the adsorption process was monitored using the Intraparticle diffusion and Boyd models. Additionally, the adsorption isotherm was examined using established models such as Langmuir, Freundlich, and Temkin isotherms. The thermodynamic characteristics of the MO adsorption process have been investigated at various adsorption temperatures using the Van't Hoff model. The results obtained from the study indicate that the process of MO adsorption adhered to the Pseudo-second-order kinetic model, the Langmuir isotherm model was found to be applicable, and spontaneous and exhibited an endothermic character. In conclusion, the developed novel amino-ethyl carboxymethyl cellulose crosslinked ampholyte hydrogels (AECMC) have successive in the removal of the MO anionic dye from contaminated wastewater.

Abstract In this study, Delonix regia seed pods (DRSPs) as a locally available material were refluxed in 90% H2SO4 to yield a novel D. regia seed pods biochar-sulfur oxide (DRB-SO). FTIR, BET, BJH, SEM, EDX, XRD, DSC and TGA were applied to investigate the characterizations of the prepared DRB-SO. Various adsorption parameters like pH effect, dye concentration effect, adsorbent dose, reaction time isotherm and kinetic study were carried out to explain the process of adsorption of methyl orange (MO) and methyl red (MR) onto DRB-SO. Langmuir's adsorption model perfectly explained the adsorption process onto the surface of DRB-SO as a monolayer. The maximum adsorption efficiency of DRB-SO was (98%) and (99.6%) for MO and MR respectively which attained after 150 min with an adsorbent dose of 0.75 g/L. The pseudo-second-order kinetic model best explained the process of adsorption of MO and MR dyes by DRB-SO. The highest observed adsorption amount was as high as 144.9 mg/g for MO dye and 285.7 mg/g for MR dye, comparable with other reported materials based on activated carbon materials. All of the outcomes signposted a prodigious perspective of the fabricated biochar composite material in wastewater treatment. Using the regenerating DRB-SO through an acid–base regeneration process, six cycles of adsorption/desorption were examined. Over the course of the cycles, there was a minor decrease in the adsorption and desorption processes. Also, it was revealed what the most plausible mechanism was for DRB-SO to absorb the ions of the MO and MR dyes.

In this study, a series of transition metal‐doped TiO2 was prepared by a simple sol‐solvothermal method. Mix an ethanol solution of tetrabutyl titanate and metal nitrate solution to obtain a homogeneous sol, which is then subjected to solvothermal treatment. After calcination, the metal‐TiO2 naoncomposite was obtained. Selected transition metal precursors, including Cu, Fe, Ag, Cr, Co and Zn, were doped into TiO2 nanocatalysts to assess photocatalytic degradation activities. The results show that 1 mol % Ag−TiO2 photocatalyst has a larger specific surface area, a stable anatase phase and the narrowest forbidden band energy (3.00 eV). In photocatalytic degradation of methyl orange (MO) tests, 1 mol % Ag−TiO2 could reach 100 % decolourisation after 70 min and 75.43 % mineralisation after 90 min. ESR analysis confirmed that Ag doping significantly increased the content of ⋅O2− and ⋅OH for the TiO2 catalyst, which are responsible for the oxidation reactions and consequently degradation of pollutants. The photocatalytic degradation mechanism of MO was also proposed. The TOC analyses confirmed the mineralization of MO. The excellent thermal and chemical stability of 1 mol % Ag−TiO2 has also been demonstrated by thermogravimetric analysis and cycling experiments. Electrochemical tests have also demonstrated the excellent electrochemical properties of 1 mol % Ag−TiO2. [ABSTRACT FROM AUTHOR]

In the current study, silver nanoparticles (AgNPs) incorporated Polyamide 66 (PA66) nanofiber mat as a photocatalyst which was prepared using electrospinning technique for degradation of methyl orange (MO). Considering the lack of reported studies on the influence of the ultrasonication on the size and stability of AgNPs, the purpose of the study was to produce a small size of AgNPs and compare it with the continuous stirring method. It is reasonable to report that the advantage of ultrasonication is to generate relatively smaller AgNPs (u-AgNPs) compared to fabrication by continuous stirring method (s-AgNPs). Helichrysum arenarium (HA) extract was used as a reducing agent as well as a capping agent in green synthesis of AgNPs. AgNPs were characterized by UV–visible spectrophotometry, Fourier-transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), and transmission electron microscope (TEM). PA66/u-AgNs nanofibers were then successfully electrospun and characterized by using scanning electron microscope (SEM), FT-IR, thermal gravimetric analysis (TGA), and water contact angle measurement (WCA). Fabricated PA66-based nanofiber mat with smooth surface and uniform diameters (330–340 nm) was used as a catalyst in MO degradation. PA66/u-AgNP nanofibers were also evaluated for antibacterial performance and showed significant inhibition against Escherichia coli, Staphylococcus aureus, and Pseudomonas aeruginosa bacteria. According to these findings, it is expected that the fabricated novel PA66/u-AgNP nanofibers can be announced as a promising potent and applied to the wastewater applications. [ABSTRACT FROM AUTHOR]

In the current work, the adsorption of acid black 1 (AB1), a hair dye, and methyl orange (MO) on anion exchange membrane BII (AEM-BII) in a binary system was studied experimentally. The effects study for contact time, adsorbent's and adsorbates' concentration, and temperature of aqueous media on the AB1 and MO removal, AEM-BII recovery, and reusability were also investigated. The highest removal was observed at optimum conditions, 150-min contact time and 5 g L−1 of adsorbent for AB1 (91.2%) and MO (83.4%). Adsorption kinetics was estimated by pseudo-first-order (PFO) and pseudo-second-order (PSO) kinetics. The experimental findings were fitted well by PSO kinetics with an adsorption capacity of 19.45 ± 0.93 and 19.34 ± 0.84 mg g−1 for ABI and MO, respectively. Moreover, the adsorption isotherm study confirmed that AB1 and MO adsorption by AEM-BII from the binary system was followed by Langmuir isotherms. Adsorption thermodynamics revealed that adsorption of both AB1 and MO by AEM-BII was endothermic and spontaneous. Moreover, the desorption phenomenon of ABI and MO from the loaded AEM-BII showed that dye removal from AEM-BII was found to be 74.95%, demonstrating AEM-BII can be considered as good adsorbent for acidic dyes from the binary system. [ABSTRACT FROM AUTHOR]

Mn-doped ZnO nanoparticles are prepared using orange peel extract and the samples are annealed at 500°C. The structural, morphological and optical properties are examined as a function of doping concentration. The Debye-Scherrer's formula, Williamson-Hall equation and Halder-Wagner method are employed to explore the crystallite size of the prepared nanoparticles. The defects of the nanoparticles are enhanced due to the addition of the dopant. The hole concentration is about 4 times greater than the electron concentration. The nanoparticles are positive-type and show the red-shifted band gap as the doping concentration of Mn increases. The enhanced zone of inhibition is observed against Bacillus subtilus, Staphylococcus aureus and Klepsiella pneumonia due to doping. A high specific capacitance of ~600 F/g is observed which corresponds to the 2% Mn-doped nanoparticles. Mn-doped ZnO nanoparticles have excellent photocatalytic activity against methyl orange dye and have the degradation efficiency of 92% in 80 min under visible light. [ABSTRACT FROM AUTHOR]

Activated carbon (ACcs) from chili straw was prepared by sequential carbonization and K2CO3 activation and applied for adsorption of cationic (methylene blue (MB)) and anionic (methyl orange (MO)) dyes with similar molecular sizes from aqueous solution. The physicochemical properties of chili straw char (Charcs) and ACcs were compared based on N2-adsorption/desorption, SEM, XRD, Raman spectroscopy, and FTIR. Activation mechanism was revealed with the aid of TG-FTIR. Batch experiments were performed to determine the isotherm models for adsorption of dyes. Results showed that ACcs possessed a large specific surface area of 1868 m2 g−1. The formation of pores was attributed to the reactions between oxygen-containing functional groups in Charcs and K2CO3 at temperatures of 670 to 850 °C. Sips model was applicable for the adsorption isotherm data for both MO and MB with outstanding maximum adsorption capacities of 1542 and 989 mg g−1, respectively. Thermodynamic analysis revealed that the adsorption processes of MO and MB were endothermic and spontaneous, and the adsorption was more spontaneous in the case of MO. Zeta potential analysis revealed that electrostatic interactions were responsible for the significant difference between the adsorption capacities for MO and MB. Thermal desorption MO from ACcs was investigated by TG-FTIR, and thermal regeneration of MO-saturated ACcs was carried out at 650 °C for 30 min, and the regeneration efficiency remained higher than 60% after five cycles. [ABSTRACT FROM AUTHOR]

The novel cationic cetyltrimethylammonium bromide (CTAB)-modified neem flower was prepared and studied to assess its adsorptive potential of methyl orange dye from the contaminated aqueous medium. The chemical structure of the neem flower (NF) and CTAB-modified neem flower was analysed using FTIR spectroscopy. The microstructure of the samples was inferred by analysing their SEM micrographs. The surface area, pore diameter, and pore volume of the CTAB-modified NF were determined by BET analysis. The adsorption of methyl orange dye onto CTAB-modified NF powder was examined under various experimental conditions. The adsorption data were analysed using Langmuir and Freundlich isotherm models, and the adsorption capacity of the bio-adsorbent was also calculated. The adsorption was found to follow second-order kinetics, and the thermodynamic parameters were also determined. [ABSTRACT FROM AUTHOR]

Effluent-containing dye molecules is a significant environmental hazard. An economical and energy-saving solution is needed to combat this issue for the purpose of environmental sustainability. In this study, Fe-Ni-Co-based trimetallic nanocomposite was synthesized using the coprecipitation method. Scanning Electron Microscopy (SEM), X-ray diffraction (XRD), and Fourier Transform Infra-Red spectroscopy were conducted to explore the physical morphology, phase structure and functional groups of the synthesized catalyst. Among dyes, methyl orange is considered as a major contaminant in textile effluent. The current study focused on the degradation of methyl orange using a trimetallic Fe-Ni-Co-based nanocomposite. A central composite design in response surface methodology was employed to analyze the independent variables including dye concentration, catalyst dose, temperature, hydrogen peroxide, irradiation time, and pH. Dye degradation has been achieved up to 81% in 20 min at the lowest initial concentration (5 mg/L) in optimized conditions. Based on ANOVA, the predicted values were in great agreement with the actual values, signifying the applicability of response surface methodology in the photocatalytic decolorization of dyeing effluents. The results gained from this research demonstrated that the synthesis method of trimetallic nanocomposite (Iron Triad) is a cost-effective and energy efficient method that can be scaled up to a higher level for industrial application. [ABSTRACT FROM AUTHOR]

Characterization and identification of potent LMEs (Lignin Modifying Enzymes) producing fungi from Dang (Gujarat) was conducted at Department of Plant Pathology, College of Agriculture, Navsari Agricultural University, Waghai in 2021-22, Fungal isolates LD1, LD4, LD5, LD9, LD15, LD19, LD20 and LD39 were screened for Lignin Modifying Enzymes (LME) on ABTS (2, 2 azinobis (3-ethylbenz-thiazoline)-6 sulphonate), Methyl orange and a-naphthol agar and observed that all the fungal strains showed color zone/clear zone on different indicator plates. However, fungal strain LD19 showed the highest potency index on both ABTS and methyl orange plates. Among the 8 selected fungal isolates, 5 produced all the three enzymes viz. laccase, lignin peroxidase (LiP) and manganese peroxidase (MnP), 2 produced two enzymes while 1 produced only one enzyme. Isolate LD19 had given maximum laccase activity at all the intervals and it was maximum at 6 DAI (206.74 U ml-1) followed by LD20 (144.79 U ml-1), LD4 (118.38 U ml-1) and LD15 (113.68 U ml-1). Maximum LiP activity was recorded in LD19 (1.314 U ml-1) at 8 DAI followed by LD1 (0.903 U ml-1) and it was lowest in LD39 (0.725 U ml-1). Maximum MnP activity was recorded in LD19 (428.65 U ml-1) at 8 DAI followed by LD39 (308.13 U ml-1), LD15 (290.18 U ml-1), LD4 (262.16 U ml-1) and MnP activity was not detected in LD1 and LD5. The highest LMEs were observed in LD19. Potential LMEs producing fungi LD19 wasidentified as Schizophyllum commune, by morphological, microscopic characteristics and molecular methods and submitted to NCBI GenBank database with accession numbers MW720154. [ABSTRACT FROM AUTHOR]

Natural rubber–silver-magnetite (NR/Ag–Fe3O4) catalyst was successfully prepared by the incorporation of Ag nanoparticles (AgNPs) into NR-coated Fe3O4 and its formation was confirmed by X-ray diffraction (XRD), transmission electron microscopy (TEM), Fourier transform infrared (FTIR), scanning electron microscopy coupled with energy dispersive X-ray (SEM/EDX) spectroscopy and atomic absorption spectroscopy (AAS) analyses. The catalytic activity of NR/Ag–Fe3O4 was evaluated towards the removal of methyl orange (MO) dye. Different experimental parameters, such as Ag loading, initial dye concentration, and temperature were investigated and discussed in detail. The NR/Ag–Fe3O4 catalyst exhibited excellent catalytic activity for the degradation of MO in the presence of potassium borohydride (KBH4) in aqueous medium. The reaction follows pseudo-first order kinetics. The degradation rate increased with increasing Ag loading and temperature, but decreased with increasing initial dye concentration. The optimized experimental parameters for the degradation process were 2.5 × 10–5 M and 40 °C. The excellent reusability of NR/Ag–Fe3O4 was indicated by the percentage (%) efficiencies of the removal of MO, which were consistently above 95%. Moreover, the lower Fermi energy of the NR/Ag–Fe3O4 catalyst than NR/Fe3O4 suggested that the presence of AgNPs enhanced the conducting properties of NR/Ag–Fe3O4, which led to better electron transfer from KBH4 to MO molecules and higher degradation rate. The presence of the NR/Ag–Fe3O4 catalyst resulted in high mineralization of the MO dye (88.95%), as confirmed by total organic carbon (TOC) analysis. [ABSTRACT FROM AUTHOR]

Biomass-based aerogels are of interest due to their abundant precursors, ease of functionalization, eco-friendliness, low cost, and effectiveness in dye-contaminated water treatment. Coconut pith (CP) known as a by-product after coconut processing is a sponge-like and lightweight material discarded in large volumes. For the first time, carbon micro-particles resulting from two-step treatment and pyrolysis of CP have been successfully incorporated with chitosan to produce aerogel composites by high-speed homogenization and freeze-drying. After pretreatment, holocellulose content and crystallinity index of the recovered CP pulp are respectively 75.4 and 58.6 % along with a solid recovery rate of 27.5 %. Characteristic properties of the aerogel composites are featured by their density as low as 15.23–28.17 mg/cm3, remarkably high porosity of 98.17–99.05 %, and Young's modulus of 1.64–12.23 kPa. Synergistic effects of the porous network, electrostatic interactions between both amine groups in chitosan and carbon surface with methyl orange (MO) cause the as-fabricated aerogel composites to achieve an extremely high adsorption capacity of 454.13 mg/g and removal efficiency of 92.32 % at initial MO concentration of 500 mg/L. Therefore, the CP-derived carbon/chitosan aerogel composites synthesized from a feasible procedure exhibit their great potential in enhancing the value of coconut waste and dealing with dye-contaminated water pollution by simple and economical adsorption. [ABSTRACT FROM AUTHOR]

In order to achieve higher degradation efficiency, it is indispensable to use photocatalysts in the field of wastewater treatment. Researching and preparing bismuth-modified TiO2 photocatalysts (Bi-TiO2 photocatalysts) and analyzing their photocatalytic performance are essential. Bismuth-based material and TiO2 solution were separately prepared, and by mixing the two substances, the bismuth-modified TiO2 photocatalyst was obtained. Using methyl orange as the test model solution, the catalytic performance of this photocatalyst at different ratios of bismuth-based material to TiO2, different temperature conditions, light conditions, and photocatalytic durations was tested to verify the impact of methyl orange solution concentration and pH value on the photocatalytic effect. Experimental results showed that when the mass ratio of bismuth-based material to TiO2 was 1∶1, the photocatalyst exhibited the best degradation and decolorization effects, demonstrating excellent photocatalytic performance. The Bi-TiO2 photocatalyst exhibited varying degrees of methyl orange degradation ability, with the degradation rate initially increasing and then decreasing with the change in the ratio of bismuth-based material to TiO2. The optimal photocatalytic performance of this catalyst was observed at a temperature of 45 ℃ and under 15 h of light exposure. When the temperature exceeded 120 ℃, the photocatalytic effect of the catalyst tended to stabilize. The photocatalytic performance was more ideal at a methyl orange mass concentration of 20 mg/L and a pH value of 4. Environmental concentration had minimal impact on the photocatalytic performance of the Bi-TiO2 photocatalyst. Regardless of the variation in methyl orange mass concentration, the catalyst exhibited strong photocatalytic effects, with the best decolorization effect observed at a methyl orange mass concentration of 20 mg/L. The catalyst showed the highest methyl orange decolorization rate at a pH value of 4. Therefore, it is evident that the introduction of bismuth significantly enhances the photocatalytic performance and visible light responsiveness of TiO2. [ABSTRACT FROM AUTHOR]

ZnO nanocomposites with different molar ratios of Ce doping were prepared by hydrothermal method using ZnO as a photocatalyst and rare earth element Ce as an additive phase. The effect of Ce doping molar ratio on the lattice structure, microstructure and photocatalytic performance of ZnO nanocomposites was studied using methyl orange (MO) dye as the degradation object. The results showed that the Ce-ZnO nanocomposites prepared were all hexagonal wurtzite structured with an irregular granular appearance. Ce doping increased the surface roughness of ZnO. After Ce doping, no new products were produced in ZnO, which did not affect the structure of ZnO. As the Ce doping molar ratio increased, the specific surface area of Ce ZnO gradually increased, the absorption edge first increased and then decreased, the bandgap width first decreased and then increased, and the photoluminescence intensity first decreased and then increased. The specific surface area of 0.6%Ce-ZnO reached 33.91 m2/g, with a maximum absorption edge of 394 nm and a minimum bandgap width of 2.97 eV, corresponding to the lowest photoluminescence intensity. The photocatalytic degradation test showed that with the increase of Ce doping molar ratio, the photocatalytic degradation of MO by Ce-ZnO first increased and then decreased. The degradation rate of MO by 0.6%Ce-ZnO reached its maximum value of 95.36% at 180 min. Under strong acidic or alkaline conditions, it wasn't conducive to the progress of photocatalytic reactions. Under weak acidic conditions with a pH value of 5, the degradation rate of MO by 0.6%Ce-ZnO reached a maximum of 99.16%. When the 0.6%Ce-ZnO photocatalyst was reused for 5 times, the degradation rate of MO still exceeded 70%, indicating good usage stability and economic benefits. [ABSTRACT FROM AUTHOR]

This work reports the synthesis of cationic surfactant-coated Au-Ag core-shell (Au@Ag) nanoparticles (NPs) via a straightforward seed-mediated approach. The UV-Vis analysis showed that the plasmon peak position of synthesized Au@Ag NPs correlated with the thickness of the Ag shell encapsulating the Au core. The Au@Ag NPs have shown impressive catalytic performance for the reduction reactions of 4-nitrophenol (4-NP) and methyl orange (MO) where the apparent rate constant experienced a remarkable increase by 67-fold and 90-fold, respectively, when Au@Ag NPs with the Ag-shell thickness of 6.3 nm were employed as a catalyst, compared to Au NPs. This multifold improvement in the activity cannot be simply accounted for by the increase in surface area of NPs and is attributed to the electronic synergistic effects between Au and Ag in the core-shell NPs. Furthermore, while Au@Ag NPs exhibited heightened antibacterial activity against both Gram-positive S. aureus and Gram-negative E. coli bacteria, this enhancement is modest. Notably, the anticipated significant enhancement attributed to Ag's renowned antibacterial properties was not observed. The presence of cationic surfactant cetyltrimethylammonium bromide (CTAB) enables both Au and Au@Ag NPs to effectively bind with the negatively charged bacterial cell membranes through electrostatic interactions. Apparently, CTAB enables both types of NPs to effectively target and eliminate bacteria with comparable efficiency. [ABSTRACT FROM AUTHOR]

In this work, the role of ascorbic acid in the process of azo dye degradation was explained. For this purpose, the kinetics of azo dye degradation under different conditions was studied. Among them, the influence of daylight protection/exposition, different concentrations of ascorbic acid (0.567–0.014 mol/dm3), and temperature (20 °C and 50 °C) on the rate of the dyes' degradation was considered. For this process, the kinetic equation was proposed, which indicates that the process of azo dye degradation using ascorbic acid is first order. Moreover, the observed rate constants were determined, and the mechanism of azo dye degradation was proposed. Spectrophotometry results, together with FTIR, fluorescence spectroscopy, and DFT calculations, explain the origin of the decolorization of the azo dyes and highlight the role of ascorbic acid in this process. Detailed analysis of the obtained products indicates that the process itself goes through several stages in which equally or more toxic compounds are formed. Obtained results from LCMS studies indicate that during tropaeolin OO degradation, 1,2-Diphenylhydrazine (m/z 185.1073) is formed. Thus, the process of azo dye degradation should be carried out in protective conditions. The proposed mechanism suggests that ascorbic acid at high content levels can be used for azo dye degradation from aqueous solution and can be an alternative method for their removal/neutralization from waste solution but with caution during the process. [ABSTRACT FROM AUTHOR]