Oxidation Of Dye Research Articles

Effect of Structurally Different Magnetic Alginate Nanocomposite Beads on Fenton-Like Oxidation of Direct Dyes

Effect of Structurally Different Magnetic Alginate Nanocomposite Beads on Fenton-Like Oxidation of Direct Dyes

Design of MgO/graphene nanocomposites for photocatalytic reduction of 4-nitrophenol and electrocatalytic oxidation of Methylene blue dye

The present study deals with the combustion synthesis of MgO/Graphene (MG) nanocomposites and investigates their photocatalytic, electrocatalytic, and photo-electrocatalytic properties for efficient redox reactions. Techniques such as FT-IR, XRD, SEM, HR-TEM, EDX, BET, and UV–vis-DRS were used to characterize MG nanocomposites. Both the photocatalytic degradation of 4-nitrophenol (4-NP) to 4-aminophenol (4-AP) and the electrocatalytic results of the MG2 nanocomposite were studied under visible light. The results showed that the MG2 nanocomposite catalyst achieved 99.07% degradation of MB dye and kinetic degradation rates of 0.114 min−1 after 40 min, compared to the catalytic activity of MG0. Thus, facile modification can effectively improve the photocatalytic reduction (toxic 4-NP to beneficial 4-AP) and electrocatalytic degradation (MB) abilities of MG0. The functions of active species in the catalytic process were investigated using various scavengers. The ·OH radicals are the reactive species responsible for the 4-NP reduction, and a possible mechanism for improved catalytic activities was also provided. Incorporating graphene under visible light boosted the MG’s activity and confirmed it to be the most effective method for handling MB dye.

A Reaction-Based Approach to Colorimetric Detection of Organic Analytes in Water Using a Chlorine-Containing Carbocyanine Dye and Hypochlorite

Water quality control employs techniques mostly targeting individual analytes; group detection is also practiced, but the choice of group methods is limited, which supports interest in developing such methods. We have examined the interaction of hypochlorite with a chlorine-containing heptamethine carbocyanine dye in the presence of 30 organic and inorganic model analytes that were found to induce diverse color changes in the system. The main supposed mechanisms are retardation of the dye oxidation with hypochlorite (presumably by scavenging chlorine radicals) and substitution of chlorine atom in the dye by the most nucleophilic analytes (amines, amino acids, proteins, DNA, phenol). The grass-green substitution product is more contrastingly visible against the dark-purple hypochlorite oxidation product of the dye than against the original emerald-green dye. The indicator reaction is monitored photographically for 10–40 min and the images are processed using principal component analysis (PCA) or linear discriminant analysis (LDA), allowing for data convolution for the complex color transitions. Nitrogen compounds are discriminated from the others, and more reactive analytes (tryptophan, cysteine, bovine serum albumin, and DNA) are detected in the presence of less reactive ones in natural water. The system is promising for the development of group assays for dissolved organic matter and the discrimination of water samples.

From waste to advanced resource: Techno-economic and life cycle assessment behind the integration of polyester recycling and glucose production to valorize fast fashion garments

This work demonstrates the technical, economical, and environmental viability of integrating enzymatic hydrolysis, mechanical refining, and total chlorine-free (TCF) bleaching processes for industrial-scale production of glucose from textile waste. The process features an innovative mechanical refining pretreatment coupled with TCF oxidation of dyes to achieve over 90% improvement in enzymatic hydrolysis yields of cotton textile waste while also promoting the purification and recycling of synthetic fibers. A comprehensive techno-economic analysis was performed based on a 14,000 bone dry tons (BD tons) annual glucose production line, utilizing both 100% cotton and cotton/polyester blends, reveals capital investments ranging from USD 5.6 to 7.9 million, with manufacturing costs per ton of glucose varying between USD 215 and USD 475, depending on the textile blend used. The cotton/polyester 50/50 blend scenario had the lowest minimum selling price (USD 290 per ton of glucose) due to the revenue from the unhydrolyzed synthetic fibers, which are a valuable and key co-product. A sensitivity analysis highlights the significant influence of recycled polyester content and market prices on the economics. Additionally, a life cycle assessment was performed to compare the carbon footprint of the four scenarios. In contrast to other existing pretreatments that can contribute to up to 70% of the emissions in enzymatic hydrolysis of textiles, the mechanical refining pretreatment can contribute as low as 10% of the total emissions in the process proposed in this work. While certain challenges remain, such as the development of a robust supply chain model, the conversion pathway shown in this work for upcycling cotton textile waste into value-added chemicals represents a promising opportunity to combat textile landfilling and foster the circular economy within the industry.

Dual boosting of the built-in polarization field in the BiFeO3/ZnS heterostructure for water purification: Effects of Z-scheme heterostructure and corona poling

In this study, we have designed a novel 1D-0D lead-free Z-scheme heterostructure of BiFeO3–ZnS (BFO/ZnS) using an isoelectric point-assistant annealing method for piezocatalytic reactions. The open circuit voltage measurements exhibited a greater internal electric field for BFO/ZnS (90/10) than for individual components, causing its excellent piezocatalytic performance for MTZ antibiotics, organic dyes oxidation, and Cr(VI) reduction. BFO/ZnS (90/10) was treated by corona poling to boost its polarization, resulting in the highest remanent polarization and dielectric constant. Piezocatalytic experiments demonstrated that BFO/ZnS (90/10; poled) can degrade 99% of RhB by 9 min ultrasonic vibration with kapp = 0.44 min−1, which is 2.5, 5.5, and 16.3 times greater than those of BFO/ZnS (90/10), BFO, and ZnS, respectively. Also, the efficiency of piezodegradation for MTZ, Cr(VI), MO, and MB over BFO/ZnS (90/10; poled) was found to be 74.5% (90 min), 84.6% (60 min), 95.3% (40 min), and 97.2% (30 min), respectively. This outstanding piezocatalytic performance of BFO/ZnS (90/10; poled) is ascribed to the enhanced built-in polarization field due to the Z-scheme heterostructure and corona poling treatment. As supported by PL and EIS analysis, the stronger built-in electric field can effectively separate and transmit the charge carriers, causing excellent piezocatalytic activity.

New Niobate Based Catalyst for Organic Dye Oxidation: A Mechanistic Approach

New Niobate Based Catalyst for Organic Dye Oxidation: A Mechanistic Approach

Photoactive Conjugated Polyelectrolyte‐Ionomer Composite Coatings for Versatile Photoreactors

AbstractConjugated polymers are promising photoactive materials for heterogeneous photocatalysis, but their limited solubility hinders the scalability in practical use. Herein, we develop polymer composites using processable conjugated polyelectrolytes and ionomers to fabricate photocatalytic thin films with visible light activity. The composite of conjugated polyelectrolytes and ionomers with identical counter anions in their side chains enables compatibility in solvents and stabilized charged states within the composite. This facilitates the development of stable coatings on diverse substrates and enhances charge separation and transport. The resulting photocatalytic thin films exhibited a 1.5‐fold increase in photocurrent response and a 7.0‐fold increase in mechanical strength compared to the pristine conjugated polymer. Photoactive coatings with polymer composites showcase the potential for synergistic photocatalytic oxidation of NADH, organic dye, and sulfide under visible light irradiation. The photocatalytic thin films are stable, versatile, and scalable for various photocatalytic reactions, showing promise for developing upscaled photoreactors.

Heterogeneous Photo-Fenton Degradation of Azo Dyes over a Magnetite-Based Catalyst: Kinetic and Thermodynamic Studies

Textile wastewater containing dyes poses significant environmental hazards. Advanced oxidative processes, especially the heterogeneous photo-Fenton process, are effective in degrading a wide range of contaminants due to high conversion rates and ease of catalyst recovery. This study evaluates the heterogeneous photodegradation of the azo dyes Acid Red 18 (AR18), Acid Red 66 (AR66), and Orange 2 (OR2) using magnetite as a catalyst. The magnetic catalyst was synthesized via a hydrothermal process at 150 °C. Experiments were conducted at room temperature, investigating the effect of catalyst dosage, pH, and initial concentrations of H2O2 and AR18 dye. Kinetic and thermodynamic studies were performed at 25, 40, and 60 °C for the three azo dyes (AR18, AR66, and OR2) and the effect of the dye structures on the degradation efficiency was investigated. At 25 °C for 0.33 mmolL−1 of dye at pH 3.0, using 1.4 gL−1 of the catalyst and 60 mgL−1 of H2O2 under UV radiation of 16.7 mWcm−2, the catalyst showed 62.3% degradation for AR18, 79.6% for AR66, and 83.8% for OR2 in 180 min of reaction. The oxidation of azo dyes under these conditions is spontaneous and endothermic. The pseudo-first-order kinetic constants indicated a strong temperature dependence with an order of reactivity of the type OR2 > AR66 > AR18, which is associated with the molecular size, steric hindrance, aromatic conjugation, electrostatic repulsion, and nature of the acid–base interactions on the catalytic surface.

Photocatalytic Oxidation of Model Organic Dyes in the Presence of Na+, $${\text{NO}}_{2}^{ - }$$, and $${\text{NO}}_{3}^{ - }$$ Ions: Theoretical and Applied Aspects

Photocatalytic Oxidation of Model Organic Dyes in the Presence of Na+, $${\text{NO}}_{2}^{ - }$$, and $${\text{NO}}_{3}^{ - }$$ Ions: Theoretical and Applied Aspects

Tuning the optical properties of PMMA polymer by using subphthalocyanine dye and metal oxide nanoparticles for flexible optoelectronic devices

Tuning the optical properties of PMMA polymer by using subphthalocyanine dye and metal oxide nanoparticles for flexible optoelectronic devices

The health implications of using hair dyes

The global rise in hair dye usage for cosmetic purposes, including gray hair coverage, is prevalent among all genders. Hair dyes are classified as permanent, semi-permanent, and temporary, differing in penetration and frequency. Concerns about safety persist, as many use hair dye without understanding potential health risks. Ahmadi et al.'s meta-analysis indicated a 10% higher cancer risk associated with hair dye, with greater risk for dark dyes and prolonged use. Takkouche et al. found increased hematological malignancy risk, while Gera et al. noted an 18.8% rise in breast cancer risk. Carcinogenic compounds like nitrosamines and PPD in oxidative dyes raise concerns, highlighting the need for safer alternatives and responsible manufacturing.

Enhanced Photocatalytic Activities of MIL‐53(Fe)‐GO Composites via a Simple Solid‐Phase Synthesis Strategy: Increasing the Exposed Active Sites and Intimate Interfacial Contact

AbstractMIL‐53(Fe)‐GO composite photocatalysts were successfully fabricated via a simple solid‐phase synthesis strategy, and they were applied as efficient visible‐light‐driven photocatalysts for the oxidation of organic dyes and the reduction of Cr(VI). The experimental results demonstrated that MIL‐53(Fe)‐GO composites exhibit enhanced photocatalytic activities compared with the pure MIL‐53(Fe) sample. Based on the photoelectrochemical analyses, the loading of GO could enhance visible‐light absorption and accelerate the separation and transfer of charge carries, leading to the improvement of photocatalytic performance. Moreover, more intimate interfacial contact and active sites in the system could be achieved via a simple solid‐phase synthesis strategy. They could also play important role in the enhancement of photocatalytic performance. Besides, a possible photocatalytic mechanism was also investigated in detail.

Harvesting high-performance electro-water oxidation and selective MB degradation through dual functional Gd2O3–La2O3 photo-electrocatalysts

Interestingly, catalytic oxygen evolution reaction (OER) in an alkaline medium with minimizing the overpotential is the most trustworthy electrocatalyst for the output of hydrogen energy from copious water electrochemical activity. Currently, amalgamated trivalent cations metal oxides have gained desirability as a low-cost anode electrocatalyst to replace noble metal-supported electrocatalysts for water oxidation and are also used for photo-degradation applications. In the present work, we have successfully synthesized Gd2O3 supported La2O3 composites via hydrothermal pathways for efficient OER and selective methylene blue (MB) degradation applications. XRD, UV–Vis DRS, FT-IR, XPS, SEM-EDX, HR-TEM, DLS, and BET analyzers confirmed the successful synthesis of photo-electrocatalysts. Gd2O3–La2O3 composites achieved 5.66 and 3.37-fold larger surface areas than La2O3 and Gd2O3, respectively. The results of the Gd2O3 supported La2O3 composite electrode demonstrated better OER performance under 1 M KOH, and it exhibited a lower Tafel slope and overpotential of 72 mV dec−1 and 310 mV at 10 mA cm−2. A chronoamperometry examination confirms that the fabricated Gd2O3–La2O3 electrode has good stability at a fixed potential of 1.540 V vs. RHE for water oxidation. Although the, Gd+3 inspired La2O3 electrode actively takes part in OER activity owing to its high Cdl value of 40.222 μF cm−2. The selective degradation of MB dye using the Gd2O3–La2O3 composite achieved an acceptable degradation efficiency of 84.80 % compared to other pollutants under UV-light irradiation for 120 min, and the specified pH condition is 9 for the degradation of MB dye, and it follows the first-order kinetics model. Notably, post-OER and photocatalytic results exhibited good stability and reusability characteristics. Therefore, the Gd2O3–La2O3 catalyst can be used for real-time water oxidation and MB dye removal from polluted water.

Visible-Light-Driven Hydrogen Release from Dye-Sensitized Hydrogen Boride Nanosheets.

Hydrogen boride (HB) nanosheets are expected to be safe and lightweight hydrogen carriers because of their high gravimetric hydrogen density (8.5 wt %) and photon-driven hydrogen release under mild conditions. However, previously reported HB nanosheets respond only to ultraviolet (UV) light to release hydrogen. In this study, we develop dye-modified HB nanosheets that can release hydrogen under visible light irradiation (>470 nm) without heat input. Hydrogen generation is initiated by electron injection from excited dye molecules into the conduction band of the HB nanosheets. The conduction band of the HB nanosheets is formed by the antibonding states of the B 2py and H 1s atomic orbitals, and the electrons injected from the dye molecules react with the protons of the HB nanosheets to release gaseous hydrogen molecules. Although the hydrogen production is terminated after long-term light irradiation owing to dye oxidation and/or loss of protons in HB nanosheets, the total amount of the released hydrogen molecules corresponds to approximately 25% of the protons in HB nanosheets even under the extra mild conditions. The addition of a sacrificial agent like iodine ions and a proton source like formic acid sustained the H2 generation from the dye-modified HB nanosheets under visible light irradiation for long term.

Enhanced photocatalytic degradation of Congo red dye into safe end-products over ZnO@polyaniline/coal composite as low cost catalyst under visible light: Pathways and ecotoxicity

ZnO@polyaniline/coal nanocomposite (ZnO@PANI/C) was synthesized and characterized by different analytical techniques as potential enhanced photocatalyst for the successful oxidation of Congo red dye (CR) into eco-friendly end-products. The investigated CR concentration (5 mg/L) was completely decolorized after 120 min, 100 min, 80 min, and 40 min after the incorporation of ZnO@PANI/C dosages at 0.2 g/L, 0.3 g/L, 0.4 g/L, and 0.5 g/L, respectively. The synergetic studies demonstrate a significant impact of the integrated components (coal, polyaniline (14.2 % oxidation of CR), ZnO (21.6 % oxidation of CR), 43.7 % (PANI/C oxidation of CR), and 64.3 % (ZnO/C oxidation of CR)) on the catalytic activity of ZnO@PANI/C (100 % oxidation of CR), which is higher than that of the individual components. The investigation of TOC content reflects that the complete mineralization can be detected after 100 min and validates the formation of different species of intermediates started by sodium-3-(phenyl diazenyl) naphthalene-1-sulfonate until detecting ethyl benzene. The findings of the oxidizing trapping tests demonstrate the controlling impact of the hydroxyl radicals as the oxidation in the presence of its trapping reagent (Isopropanol) declined to 8.6 %. The oxidation pathway of CR over ZnO@PANI/C involved a progressive series of decarboxylation and dihydroxylation ended by ethylbenzene, which in turn produced nontoxic products such as H2O and CO2. The eco-toxicity tests reflect the efficiency of the photo-oxidation of CR contaminants by ZnO@PANI/C in reducing acute toxicity (LC50 and EC50 > 100) and chronic (ChV > 10) toxicities of CR dye after 60 min of remediation.

Environmental Win–Win Management: Using Aluminum-Based Solid Waste for Synozol Red-KHL Dye Oxidation

Environmental Win–Win Management: Using Aluminum-Based Solid Waste for Synozol Red-KHL Dye Oxidation

Optical investigation of MAGAT polymer gel dosimeter embedded with methylene blue dye and zinc oxide nanoparticles using UV/Vis spectrometry pre- and post-irradiation of 6MV photon beam

Optical investigation of MAGAT polymer gel dosimeter embedded with methylene blue dye and zinc oxide nanoparticles using UV/Vis spectrometry pre- and post-irradiation of 6MV photon beam

Oxygen vacancies enhanced photo-fenton-like catalytic degradation of rhodamine B by electrochemical synthesized α-Fe2O3 nanoparticles

Hematite is widely used as a catalyst in a photo-Fenton-like process for the oxidation of dyes. We report on the electrochemical synthesis of α-Fe2O3 nanoparticles. The structure, morphology, chemical composition, and surface chemical state of the catalyst, as well as its optical and magnetic properties, were thoroughly characterized by scanning electron microscopy, X-ray diffraction spectroscopy (XRD), shift combination scattering spectroscopy, X-ray photoelectron spectroscopy (XPS), and vibrating sample magnetometry (VSM). It was found that the crystal size was 63.9 nm. It was shown that the presence of Fe2+ on the surface was due to oxygen vacancies rather than impurity phases. The optical bandgap was determined to be 1.87 eV. Nanoparticles exhibit weak ferromagnetic behavior with a magnetization of 1.09 emu/g at maximum applied magnetic field 1 kOe. The catalytic activity in the photo-Fenton-like process for the degradation of Rhodamine B (RhB) dye was investigated, and the effect of working parameters, including H2O2 concentration, catalyst concentration, and RhB concentration, on the degradation efficiency was studied. The maximum degradation rate was 99.15 % in 12 min under optimal conditions. The catalyst showed long-term stability over 5 repeated cycles.

Na/K-ATPase α1/Src Signaling Regulates Mitochondrial Metabolic Function and ROS Production in Human iPSC-derived Cardiomyocytes

Through an isoform specific mechanism, the Na/K-ATPase (NKA) α1 polypeptide-mediated regulation of Src kinase has emerged as a novel regulator of mitochondrial function in various cell types. Mitochondrial metabolism ensures adequate myocardial performance and adaptation to physiological demand. It is also a critical cellular determinant of cardiac repair and remodeling. To investigate the importance of the proposed NKA/Src regulatory signaling on cardiac mitochondrial metabolic function independently from the classic Na/K-ATPase enzymatic function, we used a gene targeting approach in cardiomyocytes. Human induced pluripotent stem cells (hiPSC) expressing a Src-signaling null mutant (A420P) form of NKA α1 were generated using CRISPR/Cas9-mediated genome editing. NKA isoform protein expression and enzymatic activity remained unchanged. However, baseline levels of Src and ERK1/2 phosphorylation were decreased by 55% and 80%, respectively in the A420P hiPSC (n=3, p<0.05). Both the WT and A420P hiPSC differentiated into cardiomyocytes (iCM) as assessed by morphology, spontaneous cell contraction, marker gene expression, and subcellular striations. Cell metabolism assessed by Seahorse extracellular flux analysis revealed significant reductions in basal and maximal rates of mitochondrial respiration (50%), spare respiratory capacity (50%), ATP production (60%), and coupling effciency (20%) (n=4, p<0.05). ROS production was monitored in live cells by measuring the oxidation of the CM-H2DCFDA dye using a fluorescence microscope. The slope of the ROS production rate curve was dramatically reduced in A420P iCM (80%, n=3, p<0.05). Protein carbonylation levels, analyzed by ELISA as markers of oxidative damage, were also decreased in A420P iCM (n=4, p<0.05). Taken together, these data provide genetic evidence for a role of NKA α1/Src in the tonic stimulation of basal mitochondrial metabolism and ROS production in human cardiac myocytes. This has potential significance in cardiometabolic diseases and suggests that targeting the NKA α1/Src signaling axis may offer a novel approach to address mitochondrial dysfunction. NIH Grant R15 HL145666, NIH Grant P20GM103434 to the West Virginia IDeA Network of Biomedical Research Excellence, and American Heart Association Postdoctoral Fellowship — 22POST917776 — to Marco T. Pessoa. This is the full abstract presented at the American Physiology Summit 2024 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.

Role of surfactants on Fe2+ mediated oxidative decolorization of Acid Red 13 by peroxydisulfate

Over the past few years, environmental concerns regarding dye contamination have grown. Removing dye from wastewater from industry is crucial for environmental sustainability. The removal of Acid Red 13 (AR13) dye was achieved through its oxidative degradation utilizing peroxydisulfate. While there are few reports on the Fe2+-mediated oxidation of azo dyes by peroxydisulfate, further investigation is needed to understand the effect of surfactants on their degradation. The present study focuses on investigating the influence of cationic, anionic, and neutral surfactants on the decolorization of Acid Red 13 (AR13) in aqueous solutions using peroxydisulfate. The decolorization kinetics of AR13 in the peroxydisulfate process adhered to the principles of second-order reaction kinetics, with a rate constant of 2.96 × 10−4 M−1 min−1 at 4.0 mM S2O8 2− concentration. A decolorization efficiency of 92.9 ± 3.6% was achieved in 120 min under optimal reaction conditions. The rate constants of the second-order chemical process demonstrated a positive association with both S2O8 2− concentration and temperature. Fe2+ activates S2O8 2− to generate sulfate radical ion, amplifying AR13 decolorization. At higher pH, sulfate-free radical production decreases, limiting AR13 decolorization. Recent findings show that CTAB (cetyltrimethylammonium bromide) and SDS (sodium dodecyl sulfate) retard Fe2+-catalyzed S2O8 2− activation, whereas no discernible impact on S2O8 2− activation was observed in the case of TX-100 (triton X-100). Peroxydisulfate decolorized AR13 with a low activation energy of 45.10 ± 1.71 kJ mol−1 at 2.0 mM starting concentration. The positive ΔG value indicates the non-spontaneity of the decolorization process.