Blue Dye Research Articles

Kinetic and thermodynamic study of the adsorption isotherm of methylene blue dye from aqueous solutions by activated carbon

The efficiency of activated carbon in wastewater as a powerful blue dye remover has been studied. In this work, activated carbon manufactured from Sidr leaves was used to adsorb methylene blue dye. The factors affecting adsorption were studied, such as the weight of the adsorbent, temperature, contact time, and initial concentration of the dye, and the optimal conditions for adsorption were determined according to the experimental results. It was evident from the experimental results obtained that the removal efficiency increases with the increase of both the weight of the adsorbent material and the contact time. It was observed that the adsorption process was possible, spontaneous, and exothermic in the temperature range (293-333 K), and this is what determined the thermodynamic variables ΔG°, ΔH°, and ΔS°. The Langmuir, Freundlich, and Timken isotherms were used to examine the experimental equilibrium data. To follow the adsorption process, two logical models were chosen, represented by the Elovage equation and diffusion.

Evaluating the Photocatalytic Activity of Green Synthesized Iron Oxide Nanoparticles

Water pollution from dyes is a major environmental challenge, demanding advanced materials for efficient degradation. In this study, we synthesized iron oxide nanoparticles (IONPs) using an aqueous extract of Senegalia catechu leaves and evaluated their photocatalytic activity in methylene blue (MB) dye degradation under sunlight irradiation. The IONPs were characterized by UV-visible spectroscopy (UV–vis), Fourier Transform Infrared Spectroscopy (FT-IR), X-ray Diffraction (XRD), Scanning Electron Microscopy (SEM), and Energy Dispersive X-ray Spectroscopy (EDS). XRD pattern showed a highly crystalline structure with an average crystallite size of 34.7 nm, while SEM images revealed predominantly spherical particles with uneven surface texture. Photocatalytic efficiency exceeded 80% MB dye degradation after 120 min of sunlight exposure. Optimization of catalyst dose, pH, dye concentration, and other parameters is essential for maximizing degradation efficiency. The IONPs demonstrated reusability over four degradation cycles, retaining effective photocatalytic performance. This study underscores the potential of green-synthesized IONPs as eco-friendly photocatalysts for wastewater treatment and environmental remediation.

Spectral and Linear Optical Properties for New Mixture of Nile Blue and Malachite Green Organic Laser Dyes

Spectral and Linear Optical Properties for New Mixture of Nile Blue and Malachite Green Organic Laser Dyes

Exploring the Impact of Ni Doping in Tuning the Bandgap, Electronic, Optoelectronic and Photocatalytic Properties of ZnFe2O4

AbstractThe exploration of semiconductor nanostructures utilizing mixed metal materials is an emerging area of study across fields including field‐effect transistors, chemical sensors, photodetectors, photocatalysts, and many more. In this study, Schottky diodes based on ZnFe2O4 (ZFO) were constructed with an aim to tune their electronic and optoelectronic characteristics. Here, Ni doping facilitated the tuning of electronic properties, leading to a significant increase in the rectification ratio from 238 to 1172, along with a reduction in the potential barrier height from 0.67 V to 0.65 V. This is attributed to Ni's role as a charge carrier in ZFO, enhancing carrier concentration, confirmed by Mott‐Schottky analysis. The 5 mol % Ni‐doped ZFO also exhibited remarkable light sensitivity, with its rectification ratio surging to 1795 under illumination, four times that of the undoped version. Additionally, its photo‐sensitivity soared to 42.46 %, nearly quadrupling the undoped device's performance, and its power gain impressively climbed to 38.4 %, which is over twelvefold the undoped sample's output. Furthermore, the diode responds strongly to optical illumination, making this structure suitable for use as a photodiode or photosensor. Apart from that by employing a doping strategy, we achieved 64.61 % degradation of methylene blue dye under visible light in 120 minutes, compared to 36.85 % for the undoped sample. These indicate that hydrothermally synthesized Ni‐doped ZFO is promising for visible light‐driven multifunctional applications.

Chitosan/modified sidr (Ziziphus spina-christi) tree leaves biocomposite for removal of methylene blue dye: characterization, adsorption optimization, isotherms, and kinetics

Chitosan/modified sidr (Ziziphus spina-christi) tree leaves biocomposite for removal of methylene blue dye: characterization, adsorption optimization, isotherms, and kinetics

Kinetic adsorption studies of methylene blue and crystal violet dyes removal in single and competitive systems using lemon peels/activated carbon/alginate composite

Kinetic adsorption studies of methylene blue and crystal violet dyes removal in single and competitive systems using lemon peels/activated carbon/alginate composite

Cnicus Benedictus roots as a low-cost adsorbent for methylene blue dye removal from aqueous solution: kinetic and equilibrium studies

In this research, Cnicus Benedictus roots powder (CBRP) was utilized as a low-cost adsorbent for removing methylene blue (MB) as a cationic dye from aqueous solution. Characterization of CBRP by Boehm titration method, Fourier transform infrared (FT-IR) and environmental scanning electron microscope (ESEM) indicates the presence of different types of functional groups and a very rough surface filled with cavities, suitable for MB adsorption. The effect of various parameters such as CBRP dose (0.2–2 g/1L), contact time (0–180 min), initial pH (1–10), coexisting anions/cations and the initial MB concentration (100–500 mg L−1) on MB adsorption were examined, the results showed that MB uptake depends on the pH of solution, the electrostatic attraction forces, the formation of H-bonds and π–π interactions are the possible CBRP–MB interaction mechanisms. Adsorption kinetic of MB on CBRP was best represented by linear and non-linear form of the pseudo-second order model. The experimental equilibrium data were best described by linear and non-linear forms of Langmuir and Redlich–Peterson isotherm models (R 2> 0.98) with a maximum MB adsorption capacity of 85.47 mg g−1 at 25 °C, the adsorption efficiency R (%) was greater than 90 (%). MB adsorption-desorption experiments showed the reusability of CBRP for five consecutive cycles. According to the obtained results, CBRP can be used as a natural adsorbent material for cationic dyes removal from aqueous solution.

Exploring chemically processed Symplocos racemosa sustainable material feasibility for sorptive amputation of methylene blue dye from waste water by green technology

Exploring chemically processed Symplocos racemosa sustainable material feasibility for sorptive amputation of methylene blue dye from waste water by green technology

Carbon fibers decorated with TiO2 nanoparticles for photocatalytic degradation of methylene blue dye

This report demonstrates the development of carbon fibers (CFs) decorated with TiO2 nanoparticles (NPs) as an efficient photocatalyst for the photocatalytic degradation of methylene blue (MB) as a model dye. Carbon fibers were produced by carbonization of polyacrylonitrile fibers, previously produced by centrifugal spinning. Subsequently, the CFs were decorated with TiO2 NPs (CFs@TiO2) by tailored soaking protocol using aqueous TiCl4 solution with different concentrations (0.025, 0.05, 0.1, and 0.2 M). SEM analyses revealed that soaking in TiCl4 produced a smooth, conformal, continuous TiO2 nanoparticulate coating with thickness increasing from 40.4 ± 21.2 to 257.9 ± 63.9 nm with increasing TiCl4 concentration. X-ray diffraction and Raman spectroscopy confirmed the anatase nature of TiO2. Photocatalytic decomposition rates of MB were assessed under UV light illumination for all CFs@TiO2 samples, and it was revealed that the lowest amount of TiO2 NP on C yielded the highest rates. The synergistic interaction between CFs and TiO2 NPs with a uniform morphology and a well-crystalline anatase structure, present in an optimal amount of fiber bodies, is the key reason for the remarkable photocatalytic performance. This work shows that C fibers decorated with an optimal amount of TiO2 NPs have a great potential as an effective photocatalytic material.

“Sunlight-driven catalytic degradation of MB dye and multi-cycle Re-usability analysis of Cu2-xSe nanoparticles”

One of the best ways to remove organic dyes based contaminant from water resources and industrial waste water is the sunlight driven photo-catalytic degradation method. The theme of the present investigation is the photocatalytic degradation of methylene blue (MB) dye using economically produced Cu2-XSe nanoparticles (NPs) catalyst under solar radiations. The Cu2-XSe NPs crystallized in the cubic structural phase with an average crystallite size around 19 nm. The direct band gap was found to be 2.1 eV. The PL spectra and corresponding CIE diagram show the Cu2-xSe NPs emitted yellow color. The SEM micrographs show that the small grains staked over others to form large grains or patches. The FTIR and EDX spectra confirmed the formation of Cu2-XSe NPs. The obtained optimum photocatalytic degradation efficiency for Cu2-XSe NPs is 90.3 %. For first cycle analysis. The pseudo-first order and second order models were used to analyze the kinetic data of Cu2-XSe NPs for varying concentrations. The multiple-cycle degradation analysis by catalyst of MB dye in one day spam for continuous four cycles were also analysed and discussed. The sun light driven multi-cycle catalytic degradation confirms the re-usability of Cu2-xSe NPs for the treatment of industrial waste water and other contaminated water bodies for the survival of aquatic life and for saving environment.

In silico screening of dyes for enhanced silk coloring using the feeding approach

Reducing redundant dyes in the production of colored silk is essential for environmental sustainability. This study aims to innovate silk dyeing processes by employing molecular docking techniques to screen a library of dyes with specific physical properties. For the first time, we identified Acid Blue 25 (Chemical Identifier, CID 22916) and Metanil Yellow (CID 11490) as cost-effective blue and yellow dyes, respectively, that enable the production of intrinsically colored silk by feeding dye-modified mulberry leaves to silkworms. Both dyes demonstrated high selective binding to silk fibroin and retained excellent color performance after degumming. Secondary structural analysis revealed that Acid Blue 25 enhanced mechanical properties by increasing β-sheet content, whereas Metanil Yellow did not. Furthermore, fluorescence spectroscopy indicated that Acid Blue 25 and Metanil Yellow effectively quenched the intrinsic fluorescence of silk fibroin primarily through static quenching, with Acid Blue 25 exhibiting a higher binding constant and more negative binding free energy. Classic molecular dynamic (cMD) simulations revealed that the extensive interaction network of Acid Blue 25, compared to Metanil Yellow, creates a thermodynamically favorable environment for dye-complex binding and stability. Overall, the combined application of virtual screening and the feeding method supports a highly cost-effective and environmentally friendly silk dyeing strategy, with the potential for scaling up in industrial applications.

Neuroprotective effects of Daphnetin on hippocampal neurons and blood-brain barrier integrity in a mouse model of cerebral ischemia

The purpose of this research was to assess the impact of different doses of Daphnetin (DAP, a natural compound derived from coumarin) on hippocampus neuronal injury, neurobehavioral function, blood-brain barrier (BBB) integrity, expression of claudin-5, brain-derived neurotrophic factor (BDNF), superoxide dismutase (SOD), and inflammatory markers in a mouse model of cerebral ischemia. Cerebral ischemia was induced in mice through 30 minutes of bilateral common carotid occlusion (BCCAO), followed by 48 hours of reperfusion. The viability of hippocampal neurons was assessed using Cresyl violet staining and BBB function was determined by measuring Evans blue (E.B) dye leakage. Spatial memory was tested using the Radial Arm Water Maze (RAWM) task. Claudin-5 and BDNF were measured by immunofluorescence, while SOD, interleukin-1 beta (IL-1β), and nuclear factor-κB (NF-κB) expression were determined through western blotting. Administering DAP significantly increased neuron survival in the hippocampus CA1, CA3, and dentate gyrus (DG) regions and improved spatial memory dose-dependently (P<0.0001). Treatment with DAP (40 mg/kg IP) significantly reduced E.B leakage and brain water content (P<0.001). Furthermore, it increased the claudin-5, BDNF, and SOD levels and diminished NF-κB and IL-1β expression (P<0.0001). The research found that DAP protected neurons in the CA1, CA3, and DG areas of the hippocampus, enhanced behavioral functions, and preserved BBB integrity in a cerebral ischemia model. This positive impact is achieved by increasing the expression of claudin-5, BDNF, and SOD and diminishing neuroinflammation. Further research is required to clarify the mechanisms and possible clinical uses.

Efficacy of white rot fungal biomass of Phanerochaete chrysosporium for adsorption and removal of reactive red and reactive blue dyes from water

Water pollution has become a worldwide issue, particularly in developing countries. This study aimed to cleanse water contaminated with reactive red (RR-198) and reactive blue (RB-19) dyes via adsorption onto nonliving white rot fungal biomass Phanerochaete chrysosporium under different operational conditions. It was found that P. chrysosporium removed more of RB-19 than RB-198. The conditions of pH 3, temperature 50 °C, adsorbent dosage 0.6 g, particle sizes of adsorbent (0.25 mm), and contact time (30 min) were optimum for removal of the dyes. RR-198 and RB-19 were removed with levels of 78.4% and 86.4%, respectively at pH 3; 79.6% and 90.0%, respectively using 0.6 g of adsorbent dosage; 82.0% and 87.0%, respectively at 30 min; and 82.0% and 87.2%, respectively at 50 °C. Thus, dead P. chrysosporium biomass was shown to be a biosorbent for the uptake of RB-19 and RR-198 dyes.

Low cost fabrication of continuous flow optofluidic microreactor for efficient dye degradation using graphene QDs@MOF (Ti) photocatalyst

The optofluidic microreactor, a convergence of optics and microfluidics, offers advanced functionalities that can be pivotal in the rapid assessment of nanocatalysts for tackling environmental contamination issues. This article presents an efficient approach for degrading Methylene blue (MB) dye, commonly used in the textile industry, within a cost-effective polydimethylsiloxane (PDMS) based continuous flow optofluidic microreactor. This microreactor combines graphene quantum dots (QDs) and NH2-MIL-125 (MOF(Ti)) as a highly effective photocatalyst coating within its microchannels. By directly incorporating graphene QDs@MOF(Ti) into the microchannels, the photocatalytic medium is brought into close proximity with the flowing MB dye solutions, thereby reducing the necessary interaction time and enhancing purification efficiency. Furthermore, the findings demonstrate an impressive degradation efficiency of ∼99% for MB dye at a flow rate of 50 μL min−1 under visible light irradiation, achieved in a single pass. Additionally, the microfluidic reactor exhibits prolonged stability of the photocatalyst, enabling its reuse without significant efficiency loss. In addition, a comparative analysis highlights the advantages of microreactor-based photocatalysis over traditional methods. These advancements in the features of the graphene QDs@MOF(Ti) nanocomposite substantiate their demonstrated superiority in degradation efficiency.

Assessment of Organobentonite’s Adsorption Kinetics for Efficient Removal of Methylene Blue Dye from Aqueous Solutions

Assessment of Organobentonite’s Adsorption Kinetics for Efficient Removal of Methylene Blue Dye from Aqueous Solutions

Adsorption Kinetic, Isotherm and Mechanism Study of Xanthate-Modified Neem Leaf Powder as an Efficient Adsorbent for Methylene Blue Dye

Adsorption Kinetic, Isotherm and Mechanism Study of Xanthate-Modified Neem Leaf Powder as an Efficient Adsorbent for Methylene Blue Dye

Hyaluronic acid-coated iron oxide nanoparticles for magnetic fluid hyperthermia and methylene blue dye removal: Preparation, physicochemical characterization, and enhancing the heating efficiency

We report here the magnetic fluid hyperthermia properties of water-dispersible hyaluronic acid-coated superparamagnetic iron oxide nanoparticles (HA-MNPs), prepared using the coprecipitation technique followed by ligand exchange. The presence of the hyaluronic acid coating is confirmed using Fourier transform infrared spectroscopy. Magneto-calorimetric studies show good field-induced heating efficiency of the HA-MNPs, where a high specific absorption rate (SAR) of ∼ 315 W/gFe is obtained for ∼ 5 wt% MNP concentration when exposed to an alternating magnetic field amplitude of ∼ 33.1 kA/m at ∼ 126 kHz. The heating efficiency is found to decrease by ∼ 33.8 % after immobilization of the MNPs within an agar matrix, which is attributed to the abrogation of Brownian relaxation. When subjected to an external DC magnetic field, the MNPs form linear chain-like structures, which causes the effective anisotropy energy density to increase. Magneto-calorimetric studies on agar-based oriented samples reveal a ∼ 19.5 % enhancement in SAR, thereby partly compensating for the loss in heating efficiency due to an increase in medium viscosity. The orientational ordering-induced enhancement in SAR is also verified using sweeping rate modified Stoner-Wohlfarth model-based calculations. In vitro cyto-toxicity studies on the HeLa cell lines reveal good cyto-compatibility of the MNPs. The negative charge on the surface of HA-coated MNPs is exploited to remove the cationic methylene blue dye from the aqueous medium, where the dye molecules are found to be physisorbed on the surface of the MNPs. The experimental findings clearly show the high induction heating efficiency, cyto-compatibility, and cationic dye-adsorption efficiency of the prepared HA-MNPs, thereby indicating the suitability of these MNPs for multi-functional applications like magnetic fluid hyperthermia and waste-water purification.

Curcumin-assisted Preparation of α-Fe2O3@TiO2 Nanocomposites for Antibacterial and Photocatalytic Activity.

Harmful microorganisms like pathogens significantly impact human health. Meanwhile, industrial growth causes pollution and water contamination by releasing untreated hazardous waste. Effective treatment of these microorganisms and contaminants is essential, and nanocomposites may be a promising solution. The present attempt demonstrates the green synthesis of α-Fe2O3@TiO2 nanocomposites (FTNCs) for the effective treatment of pathogens and organic contaminants. The α-Fe2O3@TiO2 nanocomposites (FTNCs) has been synthesized through a green approach utilizing curcumin extract. Curcumin (Turmeric) extract (TEx) was prepared by washing, drying, and crushing 5 g of turmeric, then boiling it in 100 mL distilled water at 70°C for 1 hour. Metal salts (Fe3+/Ti4+, 2:1) were added to 100 mL of TEx under continuous stirring at 70°C for 24 h. The solution was rinsed and dried at 80°C overnight and heated at 300°C for 3 h to remove impurities. Synthesized FTNCs have been tested for the potent antibacterial activity against both Gram-positive (Staphylococcus aureus, Bacillus subtilis, Enterococcus faecalis) and Gram-negative bacteria (Escherichia coli, Salmonella Abony, Pseudomonas sp.). Observations discovered noteworthy inhibition of both Gram-positive and Gramnegative bacteria by FTNCs. Furthermore, the FTNCs system shows the energy band gap of ~2.6 eV which may suppress electron recombination, thereby enhancing photocatalysis and examined against Evans blue (EB) and Congo red (CR) dyes under UV and visible light (125 W) irradiation. The remarkable photocatalytic degradation efficiency (DE) for CR reached ~67.4% in 60 min. A simple green approach has been demonstrated for the synthesis of the FTNCs using curcumin-mediated reduction. As prepared FTNCs have been evaluated for potent antibacterial activity against both Gram-positive (Staphylococcus aureus, Bacillus subtilis, Enterococcus faecalis) and Gram-negative bacteria (Escherichia coli, Salmonella Abony, Pseudomonas sp.). The results show that the highest ZID values have been obtained for 5 mg/mL concertation of FTNCs of ~14, 22,18, 21, and 20 and 29 mm for E. coli, S. abony, S. aureus, B. subtilis, E. faecalis, and Pseudomonas sp., respectively. Additionally, FTNCs demonstrate remarkable photocatalytic degradation efficiency against EB and CR dyes under UV (125 W) irradiation, achieving 56, 67% degradation within 60 minutes for EB and CR. The findings suggest that the FTNCs hold promise for long-term antimicrobial efficacy against various bacteria and offer the potential for addressing water and wastewater contaminants through photocatalysis.

Electrochemical, photocatalytic and biological investigation of carbaldehyde derived azo dye ligand and its Co(II), Ni(II), Cu(II) complexes

2-[(E)-(3-hydroxypyridin-2-yl)diazenyl]-1H-indole-3-carbaldehyde (HDC) a novel azo dye ligand and its Co(Ⅱ), Ni(Ⅱ) and Cu(Ⅱ) complexes have been prepared. The newly synthesized compounds were characterized by physiochemical techniques. The modified electrode, [Co(HDC)2Cl2]/GCE has been prepared by using the synthesized Co(Ⅱ) complex to check the electrocatalytic properties by cyclic Voltammetric (CV) studies. The biologically important molecule, folic acid present in the solution at different concentration has been detected by CV technique. The sensitivity of [Co(HDC)2Cl2]/GCE was 8.366 μAμM−1cm−2 and the limit of detection (LOD) 6.666 μM/L in the linear range 20–140 μM/L. The oxidation current of folic acid increased potentially with scan rate and the regression found was 0.9961, which indicates surface diffusion-controlled nature of process. The synthesized compounds were also screened for antimicrobial, antioxidant and anticancer activities. All the synthesized compounds gave promising results towards biological activities. The photodegradation of Methylene Blue dye was studied under visible light and in the presence of metal complexes to determine the catalytic efficiency of the synthesized metal complexes. The results indicated that the [Co(HDC)2Cl2] exhibited excellent results when compared to [Ni(HDC)2Cl2] and [Cu(HDC)2Cl2] complexes.

Artificial Neural Network Modeling of the Removal of Methylene Blue Dye Using Magnetic Clays: An Environmentally Friendly Approach

In this study, the effectiveness of Fe3O4-based clay as a cost-effective material for removing methylene blue (MB) dye from aqueous solutions was evaluated. The structural properties of the clay and Fe3O4-based clay were analyzed using SEM, XRF, BET, XRD, FTIR, and TGA techniques. In this research, the effects of various aspects, such as adsorbent amount, contact time, solution pH, adsorption temperature, and initial dye concentration, on the adsorption of Fe3O4-based clay are investigated. The experiments aimed at understanding the adsorption mechanism of Fe3O4-based clay have shown that the adsorption kinetics are accurately described by the pseudo-second order kinetic model, while the equilibrium data are well represented by the Langmuir isotherm model. The maximum adsorption capacity (qm) was calculated as 52.63 mg/g at 25 °C, 53.48 mg/g at 30 °C, and 54.64 mg/g at 35 °C. All variables affecting the MB adsorption process were systematically optimized in a controlled experimental framework. The effectiveness of the artificial neural network (ANN) model was refined by modifying variables such as the quantity of neurons in the latent layer, the number of inputs, and the learning rate. The model’s accuracy was assessed using the mean absolute percentage error (MAPE) for the removal and adsorption percentage output parameters. The coefficient of determination (R2) values for the dyestuff training, validation, and test sets were found to be 99.40%, 92.25%, and 96.30%, respectively. The ANN model demonstrated a mean squared error (MSE) of 0.614565 for the training data. For the validation dataset, the model recorded MSE values of 0.99406 for the training data, 0.92255 for the validation set, and 0.96302 for the test data. In conclusion, the examined Fe3O4-based clays offer potential as effective and cost-efficient adsorbents for purifying water containing MB dye in various industrial settings.