Degradation Of Organic Dyes Research Articles

Two novel 3D polyoxometalate-based metal–organic frameworks for structure-directed selective adsorption and photodegradation of organic dyes

Degradation of organic dyes from industrial wastewater is crucial for human health and ecological balance. Synergy adsorption and photodegradation is one of the effective methods to degrade organic dyes at present. The former is usually limited by the challenge of its the recovery and the poor adsorption capacity of the adsorbent, whereas the latter frequently suffers from sluggish reaction kinetics. Herein, the introduction of the unique electron-rich Keggin polyoxometalates (CuW12 and SiW12) into electron-deficient metal photosensitive viologen framework to construct two polyoxometalate(POM)-based metal organic frameworks (POMOFs) of 3D porous layered structures, namely [Cu2(ipbp)2(H2O)2][CuW12O40]·3H2O (1) and [Co2(H2ipbp)3(H2O)2(CoO6)2][SiW12O40]·H2O (2); (H2ipbp·Cl = 1-(3,5-dicarboxyphenyl)-4,4′-bipyridinium), which enable selective adsorption of methylene blue (MB) and effectively photocatalytic degradation cationic dyes. In addition, POMs and metal-organic frameworks act in synergy to result in much improved adsorption of certain cationic dyes as well as enhanced photocatalytic activity that allow the catalyst to show better excellent reusability and stability. The adsorption degradation rate of MB and rhodamine B (RhB) of 2 is faster than that of 1 because of the lower Zeta potential of 2 suggesting that there are electrostatic interactions in the adsorption process. This work adopted a novel view to comprehening the technology.

Fe3C@Fe decorated carbonized wood Fiber catalyst for organic dyes degradation: Preparation, characterization and mechanism

The extensive use of organic dyes has led to significant water pollution. Using lignocellulosic waste as a precursor for catalysts preparation for sewage remediation presents an effective alternative with numerous advantages in sustainability, cost-effectiveness, and environmental compatibility. In this work, wood fiber waste collected from wood processing plants was decorated with Prussian blue (PB) and then annealed to produce carbonized wood fiber catalyst (Fe3C@Fe-CB). In the presence of peroxymonosulfate (PMS), the prepared catalyst could achieve over 98.69 % efficiency in degrading methylene blue (MB) solutions (20 mg/L) in 60 min across a pH range of 3 to 11. Electrochemical test and electron paramagnetic resonance (EPR) analysis respectively verified that electron transfer pathway and radical pathway were the key factors for the degradation of MB. Cyclic degradation tests demonstrated that the degradation efficiency remained above 93.67 % after five recycling experiments. Moreover, the used magnetic catalyst can be easily recycled by magnet. This study proposed a facile and sustainable carbonized wood fiber catalyst decorated by Fe3C@Fe-CB, which could realize efficient elimination of organic dyes. Moreover, we offered a novel choice for dyes-polluted water treatment and paving a new route for converting low-value lignocellulosic waste to high-value utilizations.

Evaluation of Ruthenium Oxide Nanoparticles as Photocatalysts: Efficiency in Organic Dye Degradation and Environmental Impact Studies

ABSTRACTOne of the most promising nanoscale materials for photodegradation is ruthenium oxide nanoparticles, which are abbreviated as RuO2 nanoparticles. Ruthenium oxide nanoparticles (RuO2 NPs) are promising nanomaterials for photodegradation. Several research methods have examined their size, phase study, and shape. We also examined RuO2 nanoparticle photocatalysis in rhodamine‐B (RhB) and acridine orange (AO) dyes degradation. We discovered that these nanoparticles were highly photocatalytic when exposed to UV light. This non‐toxic method uses no solvents. Analyzing synthesized RuO2 nanoparticles required FESEM, XRD, XPS (x‐ray photoelectron spectroscopy), FTIR (Fourier transform infrared), and UV‐visible spectroscopy. The newly synthesized nanoparticles were evaluated for catalytic activity by degrading RhB and AO dyes. After the first‐order reaction, kinetics determined the photocatalytic efficiency against RhB and AO dyes, which degraded at 84% and 82%, respectively. A tamarind plant study found no phytotoxicity in treated effluents. RuO2 catalysts degrade organic dyes in industrial wastewater efficiently and inexpensively. The study shows RuO2 nanoparticles as very effective photocatalysts for degrading organic dyes, exhibiting better performance than conventional materials. In addition, it assesses the phytotoxicity of RuO2 nanoparticles, offering valuable information about their environmental consequences and safety for prospective widespread application.

Development of Monolithic Hyper-Cross-Linked Polystyrene-Supported Ultrasmall Nano-Ag Catalysts for Enhanced NaBH4-Mediated Dye Degradation.

Synthesizing catalyst supports with appropriate compositions and structures is crucial for reducing the sizes of metal nanoparticles and enhancing their catalytic activities. In this work, a series of monolithic hyper-cross-linked supports (HCP-CC) with hierarchical pores were synthesized. The monolithic structure facilitated easy operation in catalytic reactions, while the composition and structure of HCP-CC could be tailored simultaneously by utilizing the functional cross-linking agent cyanogen chloride. Furthermore, in situ loading of nano-Ag into HCP-CC resulted in the hybrid catalyst HCP-CC-Ag. The synergy of confinement and coordination effect controlled and limited the size of nano-Ag to approximately 3 nm, classifying them as ultrasmall nanoparticles, which ensured outstanding catalytic activity. This hybrid catalyst could improve the reaction rate constant to 0.423 min-1; it efficiently promoted the degradation of organic dye and exhibited great universality and recyclability, making it a potential heterogeneous catalyst for dye wastewater treatment.

Retraction of “Photocatalytic degradation of organic dyes and biological potentials of biogenic zinc oxide nanoparticles synthesized using the polar extract of Cyperus scariosus R.Br. (Cyperaceae)”

Retraction of “Photocatalytic degradation of organic dyes and biological potentials of biogenic zinc oxide nanoparticles synthesized using the polar extract of <i>Cyperus scariosus</i> R.Br. (Cyperaceae)”

Biodegradable cobalt and tin doped chitosan nanocomposites from structure tailoring to solar-driven photocatalytic degradation of toxic organic dyes.

The primary concern is the large amounts of emitted organic dyes through wastewater from numerous sectors. One of the most hazardous dyes commonly used in the industrial sector is methyl violet. It has been known to cause skin, gastric, and respiratory disorders. Therefore, a novel photocatalyst based on cobalt‑tin sulfide (Co3Sn2S2) was prepared using the solvothermal process. The photocatalyst was supplemented with Chitosan to prepare the cobalt tin sulfide-chitosan composite (Co3Sn2S2/Chi) for the photocatalytic degradation of methyl violet dye. Based on EDX analysis, a definite ratio of tin, cobalt, and sulfide was found. The FTIR of Co3Sn2S2/Chi revealed the characteristic bands of chitosan and metal sulfide bonds. SEM results showed that the particle had an irregular shape. The composite's crystalline structure was identified by XRD analysis as being 56 nm in crystalline size. The photocatalyst had a narrow band gap of 1.02 eV. At ideal conditions, the developed photocatalyst demonstrated greater degradation efficiency of methyl violet dye under solar light irradiation. The photocatalyst successfully decomposed 95 % of the methyl violet dye (40 ppm) within 70 min, operating at a pH of 9.0. This remarkable degradation was achieved by employing 0.25 g of the photocatalyst. The photocatalyst is more appealing and can be reused for up to three successive cycles. The photocatalyst is well-suited for "pseudo-first-order kinetics" to decontaminate methyl violet dye. The novel photocatalyst showed the most robust ability to decolorize methyl violet when exposed to sunlight and was a viable substitute for dye detoxification of organic dyes from wastewater.

Copper–Chitosan-Modified Magnetic Textile as a Peroxidase-Mimetic Catalyst for Dye Removal

Copper chitosan attached to a magnetic synthetic nonwoven textile was manufactured using a simple, rapid, and green procedure employing chitosan dissolved in diluted acetic acid and treatment with copper sulfate solution. The prepared copper–chitosan-modified textile exhibited peroxidase-mimetic activity which was subsequently used for the degradation (decolorization) of important organic dyes, namely methylene blue, Congo red, and Bismarck brown Y, in the presence of hydrogen peroxide. After 5 h of treatment at 22 °C, 87.5%, 79.5%, and 87.7% dye removal were observed for methylene blue, Congo red, and Bismarck brown Y, respectively. The textile bound catalyst can be easily recovered from the reaction mixture after the process is completed.

Research on Graphitic Carbon Nitride (g-C3N4) prepared by template-based method and its photocatalytic properties

Abstract. The Graphitic Carbon Nitride (g-C3N4), a non-metallic polymer photocatalytic material, has a wide range of raw materials and a simple preparation process. Due to its unique electronic structure and excellent photocatalytic performance, g-C3N4 has attracted wide attention in the field of environmental purification and energy conversion in recent years. However, g-C3N4 faces a lot of challenges, including a wide band gap, many interlayer defects, and poor interlayer electron transport. Nevertheless, its unique semiconductor structure and chemical stability still provide the possibility to explore the effect of its piezoelectric properties on photocatalysis, which paves the way for a novel approach to environmentally friendly hydrogen production. Therefore, the paper delves into the application of different template methods in the preparation of g-C3N4 by reviewing the related literature, and analyzes the role of different template materials in the preparation. In addition, in this paper, the photocatalytic properties of g-C3N4 are explored, which are mainly reflected in the photocatalytic water separation performance and photocatalytic degradation of organic dyes. It is found that the g-C3N4 shows great potential in the fields of photocatalytic water decomposition for hydrogen production and degradation of organic pollutants due to its unique band gap, nontoxicity, low cost and wide range of sources. Future research should continue to explore more kinds of template materials and their preparation processes, with the aim of realizing further enhancement of the performance of g-C3N4 photocatalysts and promoting their practical applications in the fields of environment and energy.

Studying the properties of green synthesized silver oxide nanoparticles in the application of organic dye degradation under visible light.

In present study the green synthesis of silver oxide nanoparticles has been effectively achieved using novel plant extract Phragmanthera Macrosolen. This method provides sustainable alternative for nanoparticle synthesis, demonstrating the potential of Phragmanthera Macrosolen as a reducing and stabilizing agent in the production of Ag2O NPs. The synthesized nanoparticles were characterized for their structural, morphological, and optical properties, confirming their successful formation and potential applications in various fields. The effects of different pH values and annealing temperature of the samples on the properties of Ag2O NPs formations, as well as photo-catalytic activities towards Toluidine Blue dye degradations, were studied. Powder XRD reveals that the crystallite natures of Ag2O NPs a long with crystalline size ranges from 25.85 to 35.90nm. FIB-SEM and HR-TEM images displayed that the Ag2O NPs as spherical shapes. UV-vis spectroscopy displayed that Ag2O NPs belong to a direct-band gap of 2.1-2.6eV. FTIR- study shown that the green synthesized Ag2O NPs may be steadied via the interfaces of -OH as well as C = O groups in the carbohydrate, flavonoid, tannin, as well as phenolic acid existing in P. macrosolen L. leaf. The chemical states, electron-hole recombinations and purity of Ag and O in the synthesized Ag2O NPs were confirmed through X-ray Photoelectron Spectroscopy (XPS) and PL analysis respectively. Fascinatingly, the synthesized Ag2O NPs at pH 12 displayed high photo-catalytic degradations for TB dyes. The photo-catalytic degradations of the TB dyes were monitored spectro-photo-metrically in wave-length ranges of 200-900nm, as well as high efficiency (98.50%) with half-life of 9.5798min and kinetic rate constant of 0.07234min-1, was obtained after 45min of reactions. From this study, it can be concluded that Ag2O NPs synthesized from Phragmanthera Macrosolen aqueous extract are promising in the remediation of environmental pollution and water treatment. In this light, the study reports that Phragmanthera Macrosolen green synthesis of Ag2O NPs can effectively address environmental pollution in cost-effective, eco-friendly, and sustainable ways.

Photocatalytic degradation of organic dyes under sunlight using a mononuclear Zn complex-embedded-functionalized porous material.

In this study, mesoporous materials (MCM-41 and MCM-48) were synthesized and functionalized with an acid group through a post-synthetic modification method. A mononuclear Zn complex [Zn(dmp)Cl2] (dmp = neocuprine) was also prepared and incorporated into a functionalized mesoporous material. Extensive characterization of the material married was carried out using techniques such as X-ray diffraction (XRD), Brunauer-Emmett-Teller (BET) analysis, scanning electron microscopy (SEM), nuclear magnetic resonance (NMR), and Fourier-transform infrared spectroscopy (FT-IR) to evaluate the characteristics of modified materials. The characterization results revealed that the post-synthetic modification did not alter the phase purity, crystallinity, or morphology of the mesoporous materials while confirming the successful grafting of the desired sulphonic acid functionality and Zn complex. The Zn complex-grafted-functionalized mesoporous materials were then assessed for their photo-degradation using methylene blue (MB) and rhodamine B (RB). The results demonstrated exceptional photo-degradation efficiency of the modified materials under sunlight. Within 15min, 10mg/ml of dye concentration, and adsorbent dosage 0.15mg/ml and 0.1mg/ml, degradation efficiencies of 99% and 92%, were achieved for MB using M-48-S-Zn1 and M-41-S-Zn1, respectively. Similarly, 91% and 78% degradation rates were achieved within 30min for RB using the same materials. The modified mesoporous materials exhibited a remarkable degradation performance even in challenging environments, including highly acidic, basic, and salt-concentrated conditions. This highlights the versatility and robustness of the modified materials in different environmental scenarios.

Photocatalytic degradation of organic dyes using titania modified with adsorbent nanolayers

Photocatalytic degradation of organic dyes using titania modified with adsorbent nanolayers

Al-N3 Bridge Site Enabling Interlayer Charge Transfer Boosts the Direct Photosynthesis of Hydrogen Peroxide from Water and Air.

Manipulating the electronic environment of the reactive center to lower the energy barrier of the rate-determining water oxidation step for boosting the direct generation of H2O2 from water, air, and sunlight is fascinating yet remains a grand challenge. Driven by a first-principles screening across a series of metal single atoms in carbon nitride, we report a class of an Al-N3 bridge site enabling interlayer charge transfer in carbon nitride nanotubes (CNNT-Al) for the highly efficient photosynthesis of H2O2 directly from water, oxygen, and sunlight. We demonstrate that the interlayered Al-N3 bridge site in CNNT-Al is able to activate the neighboring surface N atom for promoting the rate-determining step of the two-electron water oxidation to H2O2. It is also able to act as a bridge for enhancing the vertical interlaminar charge transfer due to the hybridization between the 3s and 3p states of the interstitial Al atom and the conduction band of two adjacent carbon nitride layers. Collectively, these factors lead to a highest photocatalytic mass activity of 1410.2 μmol g-1 h-1 (with a photocatalyst concentration of 1 g L-1) for direct photosynthesis of H2O2 out of all CN-based photocatalysts and a 7-fold higher solar-to-chemical conversion efficiency (0.73%) compared to that of the natural photosynthesis of typical plants (∼0.1%). Most importantly, the CNNT-Al-based flow reactor can steadily produce H2O2 for 200 h and be directly used for the on-site degradation of organic dye in water. The CNNT-Al-based flow reactor can also kill a 10 times higher concentration of bacteria in deionized water than that in natural water with 100% efficiency, which makes our design economically appealing for practical water treatment.

Iron complexes synthesized from FeOCl with carboxylic acid based ligands as Fenton-like catalysts for the highly efficient degradation of organic dyes over a wide pH range

Iron-based materials have garnered significant attention as Fenton-like catalysts for the degradation of organic dyes. However, challenges remain in optimizing hydroxyl radical (•OH) utilization and broadening the effective pH range for practical applications. In this study, three iron-based catalysts (complex 1, 2, 3) were synthesized via a hydrothermal method, utilizing iron oxychloride (FeOCl) as the metal ion source and 4,5-imidazole dicarboxylic acid, furan-2,5-dicarboxylic acid, and 5-hydroxyisophthalic acid as ligands, respectively. The results indicate that these synthesized Fe-based catalysts exhibit enhanced visible light absorption and superior photo-Fenton activity, outperforming FeOCl in the degradation of rhodamine B (Rh-B), crystal violet (CV), and methylene blue (MB). Moreover, the Fe-based catalyst system operates effectively over a wide pH range (1–8) and efficiently degrades organic dyes. In free radical scavenging experiments, hydroxyl radicals (•OH) and superoxide radicals (•O2-) were identified as the primary agents responsible for photocatalytic degradation. Among the catalysts, complex 1 displayed notable stability, retaining its catalytic activity after three reuse cycles. This work presents a promising approach for designing highly efficient and stable Fenton-like catalysts, offering excellent environmental remediation capabilities across a broad pH range.

Fe-based monolithic catalysts for Fenton-like degradation of organic dyes: The important role of Fe2(OH)3Cl species

Fe-based monolithic catalysts for Fenton-like degradation of organic dyes: The important role of Fe2(OH)3Cl species

Zinc/lead bimetallic sulfides as hybrid material for high-performance aqueous asymmetric supercapacitor and photocatalytic degradation of organic dye

Zinc/lead bimetallic sulfides as hybrid material for high-performance aqueous asymmetric supercapacitor and photocatalytic degradation of organic dye

Fabrication of Gd2O3-Loaded Nitrogen-rich C3N5@PANI Hybrid Nanocomposites: Unlocking Efficient Photocatalysis for Long-Term Organic Dye Degradation in Wastewater Treatment

Fabrication of Gd2O3-Loaded Nitrogen-rich C3N5@PANI Hybrid Nanocomposites: Unlocking Efficient Photocatalysis for Long-Term Organic Dye Degradation in Wastewater Treatment

Development of flexible and mesoporous CdS/ZnS/PVDF nanocomposites with remarkable organic dye degradation performance under natural sunlight

The engineering of polymer-based nanocomposites is a highly promising strategy for improving both the efficiency and stability of catalysts used in wastewater treatment. In this work, we explore the efficacy of flexible CdS/ZnS/PVDF nanocomposite films towards degradation of Malachite Green dye under low energy visible light and ambient sunlight. Films with varying weight percentage of CdS/ZnS nanofillers (0 %, 5 %, 10 %, 15 %, 20 %) were successfully prepared by solution casting method and the physiochemical properties were characterized using various techniques such as XRD, SEM, AFM, EDX, BET, UV–Vis DRS and FTIR. Pore diameter of 5.5 nm was observed, indicating that CdS/ZnS is mesoporous in nature. Under the optimum photocatalytic condition of 15 ppm dye concentration and pH 9, 15 wt% CdS/ZnS/PVDF showed the maximum photodegradation efficiency of 93.5 % in 30 min. The sample exhibited excellent reusability for five consecutive runs of the experiments which show a degradation percentage of 92.1 % in the fifth run and the scavenging study established that superoxide radicals play the major role in the photodegradation process. The experiments under natural sunlight on three separate days showed a remarkable photodegradation performance of 89 %, 93.4 % and 93.6 % highlighting the potential of CdS/ZnS/PVDF nanocomposites for sustainable wastewater treatment under natural sunlight.

Polydopamine‐Mediated Gold Nanostructure‐Decorated Electrospun Polycaprolactone Fibers for Photocatalytic Dye Degradation

AbstractMetallic nanoparticle (NP)‐decorated electrospun micro/nanofibers as an ideal photocatalytic system for the degradation of organic dyes may provide unique advantages in terms of 3D morphology with high surface area, well‐controlled porosity, low cost, good interconnectivity, and excellent flexibility. However, novel, flexible, low‐cost, and efficient fabrication methods are still demanded to obtain photocatalytic activity. In this report, for the first time, we propose gold NP (AuNP)‐decorated electrospun poly(Ɛ‐caprolactone) (PCL) membrane fibers through a conformal thin layer of polydopamine (PDA). Herein, PDA could reduce the Au3+ ions and enable the adsorption of AuNPs without using any reducing agent or seed material. The proposed system could degrade methylene blue after a 6‐h of daylight exposure with a rate constant of 4.83 × 10−3 and 4.64 × 10−3 min−1 for citrate‐stabilized AuNPs and reduction of Au ions cases, respectively. Even after fifth cycle of usage, AuNP‐decorated electrospun fibers showed reasonable catalytic activity without any significant change in their morphology and chemical content. For the case of rhodamine 6G, the same systems provided 55.2% and 64.1% of dye degradation within a 5‐h exposure. The proposed system presents unique advantages regarding control, flexibility, low cost, and efficiency in various catalytic applications.

Cu2ZnSnS4 Nanoparticles as an Efficient Photocatalyst for the Degradation of Diclofenac in Water

Dangerous emerging water micropollutants like Diclofenac are harming ecosystems all over the planet, and immediate action is needed. The large bandgap photocatalysts conventionally used to degrade them need to be more efficient. Cu2ZnSnS4, a well-known light absorber in photovoltaics with a bandgap of 1.5 eV, can efficiently harvest an abundant portion of the solar spectrum. However, its photocatalytic activity has so far only been reported in relation to the degradation of organic dyes, and it is usually used as a benchmark to assess the activity of a photocatalyst without testing its actual potential on a hazardous water micropollutant conventionally encountered in primary and secondary waters. Here, we report the promising photocatalytic activity of Cu2ZnSnS4 nanoparticles in the degradation of Diclofenac, chosen as a benchmark for dangerous emerging water micropollutants.

Harnessing the interfacial charge transfer in Mn-doped γ-Fe2O3@ZnO heterojunction for broad spectrum photocatalytic degradation of organic dyes

Developing affordable, sustainable, and environmentally friendly water remediation strategies is inevitable to achieve water security worldwide. To align with these challenges, this investigation successfully synthesized low-cost Mn-doped iron oxide and its heterojunction with Zinc Oxide (ZnO) as an efficient recovery mechanism for deteriorated water. Comprehensive characterization of Mn-doped γ-Fe2O3@ZnO heterojunction was performed using X-ray diffraction, Fourier transform infrared spectroscopy, Scanning electron microscopy, Energy dispersive X-ray, and Photoluminescence analysis. The electrical behaviors of all samples were characterized using Electrochemical impedance spectroscopy and Mott-Schottky analysis. This heterojunction showed distinct structural features along with a bandgap energy of 2.61 eV, confirming the formation of a heterojunction. The effectiveness of this heterojunction was assessed using Congo red (CR) and Crystal violet as model pollutants. The photodegradation capability using a small amount of as-synthesized photocatalyst (10 mg) reached 90.8 % for CR and 90.5 % for CV under natural sunlight for a duration of 105 min. The key findings of this report clearly demonstrated the effectiveness of the interfacial charge transfer mechanism of Mn-γ-Fe2O3@ZnO heterojunction towards the degradation of organic water contaminants.