Photocatalytic Degradation Of Toxic Dyes Research Articles

Synthesis and Characterization of Zn-loaded Ziziphus mauritiana Seeds Activated Carbon Composites for Enhanced Photocatalytic Degradation of Toxic Dyes in Aqueous Solutions

Synthesis and Characterization of Zn-loaded Ziziphus mauritiana Seeds Activated Carbon Composites for Enhanced Photocatalytic Degradation of Toxic Dyes in Aqueous Solutions

Effective development and utilization of SILAR-assisted TiO2 and CsPb2Br5 nanocomposites for photochemical and biological cleaning of environment

Recently, cesium lead halide perovskites such as CsPb2Br5 and CsPbBr3 have drawn the attention of researchers because of their unique optical, electronic, and chemical properties. To improve the photo and/or chemical performance of such CsPb2Br5 (termed as CPB hereafter), we have realized multiple facile routes for its combination with UV-active TiO2 nanoparticles. Resultantly developed binary nanocomposites of TiO2, CPB perovskites and TiO2/CPB-nanocomposite (TiO2/CPB-NC) offered a meaningful photochemical contrast between pseudo-successive ionic layer adsorption and reaction (p-SILAR) and electrostatic self-assembly methods for targeting photocatalytic degradation of toxic dyes under solar irradiation and resulted significant performance as reactant for oxygen evolution (OER) as revealed by extensive electrochemical impedance spectroscopy (EIS). In parallel to extensive material-based characterization using SEM, XRD, and UV Vis. etc, the study was further extended to the theoretical investigation of the structure of CsPb2Br5, and antibacterial activity against gram-positive and gram-negative bacteria namely Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus). RhB degradation of TiO2 increased from 13% to 58% by deposition of CPB, in parallel to 100% inhition zone growth.

One-pot synthesis of carbon dots from neem resin and the selective detection of Fe(ii) ions and photocatalytic degradation of toxic dyes

Neem resin-derived CDs (NR-CDs) exhibited a quantum yield of 21%, allowing them for multiple applications in sensitive detection of Fe2+ ions, and also in the degradation of multiple dyes in the presence of NaBH4.

Escherichia coli-assisted synthesis of AgFeO2 nanoparticles for antimicrobial, photocatalytic and hydrogen generation applications

The nanoparticles produced by physical and chemical methods are toxic in one or other way. Green chemistry is an emerging, stable and eco-friendly approach for biological production of nanomaterials. In the present study, Escherichia coli bacterium was utilized for the synthesis of silver iron oxide (AgFeO2) nanoparticles by using precursors of two different salts; iron nitrate (Fe(No3)3 and silver nitrate (AgNO3). Synthesized nanoparticles were characterized by EDX, XRD and SEM. AgFeO2 nanoparticles, members of delafossite family were appraised for bacterial inactivation, photocatalytic degradation of toxic dyes and hydrogen generation through methanolysis. Delafossites are chemically stable compounds with high conductivity and decomposition temperatures (800–925 °C). The antimicrobial activity of AgFeO2 nanoparticles was checked by well diffusion method against ATTC cultures of Escherichia coli, Bacillus subtilis, Staphylococcus aureus and Pseudomonas aeruginosa. Synthesized AgFeO2 nanoparticles were employed for the degradation of Cango red and maximum degradation of 87 % was accomplished with 20 ppm (50 mL) solution of Cango red and 0.10 g AgFeO2 as catalyst and reasonable hydrogen generating potential was also exhibited by the synthesized nanoparticles. As model fungi, Aspergillus niger and Mucor piriformis, are both significantly inhibited by AgFeO2 NPs, while M. piriformis is the target of the compound's greater antifungal action.

One-minute ultrasound-assisted synthesis of nanostructured silver particles extracted from Desmodium gangeticum for enhanced photocatalytic degradation of toxic dyes and antibacterial studies

In the present work, we are reporting a one-minute synthesis of silver nanoparticles using Desmodium gangeticum seed extract by ultrasonication method and their photocatalytic degradation of toxic dyes. The surface plasmon resonance (SPR) band of DG-AgNPs was observedat 411 nm. The calculated average particle size was 14.23 nm by HR-TEM. Toxic dyes such as Indigo Carmine, Crystal Violet, Aniline Blue, and Brilliant Blue have been degraded using DG-AgNPs as photocatalysts. Furthermore, DG-AgNPs,antibacterial activity was examined against the gram-positive and negative pathogens Staphylococcus aureus and Escherichia coli, the DG-AgNPs have shown excellent antibacterial efficacy.

Bio-fabricated silver nanocatalyst for photocatalytic degradation and organic transformation of toxic pollutants

Water pollution is major issue in global due rapid industrialization. The release of textile dyes from the industries to the environment has become a significant health issue to humans, trees and animals. The work describes the green synthesis of Mexican mint leaves plant derived silver nanoparticles (MM-AgNPs). The synthesized MM-AgNPs was well characterized by several techniques. MM-AgNPs used as photocatalytic degradation of toxic dyes and catalytic transformation of 4-nitrophenol into 4-aminophenol. Interestingly, Toluidine blue, Congo red, Pyronine Y dye, after mixing with NaBH4 and MM-AgNPs were completely decolorized. The degradation efficiency was calculated for each dye and kinetic parameters. Also, MM-AgNPs act good catalyst for the decolorized of dyes from industrial wastewater and degradation mechanism was proposed. Further synthesized MM-AgNPs applied as a catalyst for the reduction of 4-nitrophenol to 4-aminophenol within 8 min. Finally, this work is more suitable for the good photocatalytic degradation and reduction in the filled of interdisciplinary material science and environmental science.

Investigation of photocatalytic degradation of toxic dye in aqueous solution in the presence of Na-13X-supported TiO2 composite

Investigation of photocatalytic degradation of toxic dye in aqueous solution in the presence of Na-13X-supported TiO2 composite

Photocatalytic Degradation of Toxic Dyes and Antimicrobial Activities by Cadmium Doped Magnesium Ferrites Synthesized by Combustion Method

Photocatalytic Degradation of Toxic Dyes and Antimicrobial Activities by Cadmium Doped Magnesium Ferrites Synthesized by Combustion Method

Enhanced Thermal Diffusivity and Photocatalytic Dye Degradation Capability of Zinc Ferrite/Silver/Silver Chloride Nanocomposites

Herein, we report for the first time the thermal diffusivity of zinc ferrite/ silver/ silver chloride nanocomposite with a four-fold enhancement in comparison with the base fluid. A systematic analysis of the dependence of calcination temperature and synthesis routes on the crystallinity of nanocomposites of zinc ferrite with silver and silver chloride suiting it for diverse applications was done. Synthesized via the co-precipitation method, the samples were characterized using X-ray diffraction, Field emission scanning electron microscopy, Energy dispersive X-ray, Vibration sample magnetometer, ultraviolet-visible Diffusive Reflective spectroscopy and Photoluminescence studies. A zeta potential of -31.1mV was obtained for the sample showing good colloidal stability. The thermal diffusivity of the samples as nanofluids was analyzed using the dual beam thermal lens method. The study also envisages the magnetically retrievable and visible light-active nature of the synthesized samples indicating their suitability for photocatalytic degradation of toxic dyes. The work on photocatalytic degradation of methylene blue stands out in attaining rapid, efficient dye degradation of 98% within 90 minutes of sunlight exposure in comparison with unblended zinc ferrite nanoparticles even without any oxidizing agent.

Development and application of redox active GO supported CeO2/In2O3 nanocomposite for photocatalytic degradation of toxic dyes and electrochemical detection of sulfamaxole

In the current study, we reported the hydrothermal fabrication of graphene oxide supported In2O3/CeO2 ternary nanocomposite for enhanced photodegradation of two dyes and electrochemical sensing of antibiotic, sulfamaxole. The synthesised nanocomposites were characterized by several physical and analytical techniques, confirming the successful anchorage of In2O3/CeO2 on the conjugated network of graphene oxide (GO). The photocatalytic efficiency of the prepared nanocomposite was examined with the degradation of two textile dyes, Congo red (CR) and methylene blue (MB) in presence of visible light. The photocatalytic performance was seen to increase with the decoration of redox active binary nanocomposite on the conjugated network of GO which has showed maximum degradation of 94% in 130 min and 95% in 91 min for CR and MB respectively. Moreover, electrochemical and electroanalytical activity of the composite advocated excellent response towards detection of the sulfa drug, sulfamaxole. The proposed sensor platform exhibited quick response with excellent sensitivity (4.635 µA mM−1 cm−2), efficient charge transfer and a lower detection limit (0.036 µM). Additionally, the sensor system demonstrated excellent stability, good reproducibility and selective performance with little loss in activity. The increased degradation and excellent redox behaviour of composite nanostructure can be ascribed to increased photon absorption, efficient charge transfer across the interfaces and suppression of charge recombination. It is pertinent to mention that current study has paved the way to design multifunctional catalysts for mitigating the contamination legacy of persistent pollutants.

Enhanced and rapid photocatalytic degradation of toxic dyes by cobalt oxide and modified cobalt oxide under solar light irradiation

A solar light driven photo degradation approach for methylene blue (MB, model molecule of the thiazine dyes class) and malachite green (MG, model molecule of the triphenylmethane category) abatement by Co3O4 and Cr-Co3O4 spinel nanoparticles is reported. The effect of chromium load (5, 10 and 15%) in Co3O4 particles, synthesized by a simple co-precipitation process, was properly studied. The structural and morphological characteristics, chemical composition and optical properties of the materials were investigated by X-ray diffraction (XRD), Transmission Electron Microscopy(TEM), Field Emission Scanning Electron Microscopy – Energy Dispersive Spectroscopy (FE-SEM-EDS), FT-IR spectroscopy, UV–Vis diffuse reflectance spectroscopy (DRS),photoluminescence (PL) and BET surface area analysis. It was observed that properly tuning the initial pH, the initial dye concentration, the agitation time, and the photocatalyst dose, (10)Cr-Co3O4 exhibited an enhanced photocatalytic activity compared to that of pristine Co3O4, demonstrating the positive role of Cr doping In fact, the PL investigation showed that Cr doping in the Co3O4 lattice greatly increase the separation of electron-hole (e−/h+) pairs, whereas the UV DRS spectra and Tauc plot revealed a decrease in the band gap energy for Cr-Co3O4,. The investigations demonstrated that the MB dye degradation increases from 88% to 96% at pH = 11 after doping of Co3Oby 10% of Cr. Similarly, the Cr doping allowed to enhance the MG dye degradation from 85% to 92% at pH = 9. The photo degradation kinetics of both MB and MG dyes by Cr-Co3O4 and Co3O4 NPs were of pseudo-first-order mode. The active species involved in the photocatalytic process were properly identified using various scavengers by trapping holes and radicals. Finally, the photocatalysts showed good stability during recycling maintaining high performances after 5-time usage. .

Corrigendum to “Magnetically separable ZnO/ZnFe2O4 and ZnO/CoFe2O4 photocatalysts supported onto nitrogen doped graphene for photocatalytic degradation of toxic dyes” [Arab. J. Chem. 13(2) (2020) 4324–4340

Corrigendum to “Magnetically separable ZnO/ZnFe2O4 and ZnO/CoFe2O4 photocatalysts supported onto nitrogen doped graphene for photocatalytic degradation of toxic dyes” [Arab. J. Chem. 13(2) (2020) 4324–4340

Photo-Catalytic Degradation of Toxic Dyes by Silver Nano Particles Synthesized From Peels Extracts of Citrus medic at Through Green Method

Abstract-Dyes are chemical compounds which are used to convey colour to various materials, but during the processing and operation it produces toxics and hazardous side product which is very harmful to ecosystem and biodiversity. Researchers are developing various methods to degrade such toxic dyes and use of noble metal nano particle as a catalyst is emerging field of interest among scientific community. In this research article we had scanned our previously synthesized silver nanoparticle from Citrus medicapeels extracts; Synthesis and characterization were previously reported by authors.SynthesizedAgNPs has excellent photo-catalytic potential against various toxic dyes like Methylene blue, Rose bengal, Acridine Orange, Methyl Orange. Our nano-catalyst methylene blue nearly 52.15% in 5 hours while in absence of nano-catalyst dye degrades nearly32.85%. It is also capable of degrading acridine orange study shows it degrade Acridine orange dye 58.74% in just 4 hours and rose bengal dye 59.57 % followed by 4 hours of Continuous UV absorption. It also degrades methyl orange dye nearly 52% in 10 hours of solar irradiation. Synthesized AgNPs can be used as photo-catalyst for degrading toxic dyes.

Synthesis of mesoporous BiOI flower and facile in-situ preparation of BiOI/BiOCl mixture for enhanced photocatalytic degradation of toxic dye, Rhodamine-B

Porous flower-like BiOI possessing excellent and wonderful activity in visible light induced photo-catalytic degradation of Rhodamine-B, have been synthesized by facile solvothermal method. X-ray diffractometer, microscopes and spectroscopes are employed to study the phase structure, nano-dimension, purity and morphology of synthesized and used catalysts. The degradation using BiOI is increased from 74 to 99.2 % within 1 h for in-situ formation of BiOI/BiOCl mixture in media of aqueous BiOI containing Cl− ion. The study of reaction parameters reveals high efficiency of mixed catalyst with maximum removal of the dye achieved up to 99.2 % in 1 h for a dye concentration of 5 mg/L at pH 3. Possible degradation products are detected, scavenger-effects determined and mechanisms proposed.

High performance MnO2–Al2O3 nanocomposite as white light photocatalyst and bactericidal agent: Insights on photoluminescence and intrinsic mechanism

Mn-based photocatalyst and antimicrobial agent was synthesized by ultrasonic-assisted co-precipitation method by keeping MnO2 as active compound and Al2O3 was adopted as catalyst support. XRD and HRTEM analysis verified the co-existence of MnO2 and Al2O3 and the crystalline nature of NCs. The XPS and EDAX revealed the chemical states of elements namely Mn2p, Al2p and O1s. The presence of Mn–O and Al–O–Al bonds were noted through FTIR. The photon absorption ability of NCs in visible region was favoured by the energy bandgap of 2.51 eV. Photoluminescence revealed that the charge carriers in NCs showed an improvement in life time. The NCs exhibited enhanced photocatalytic effect due to its synergetic effect and the photocatalytic performance can be ordered as MnO2/Al2O3 > MnO2 > Al2O3. The enhancement in photocatalysis rate in NCs was attributed by the formation of heterostructure and it prevent the recombination of charge carriers. The OH· radical was the dominant species in dye degradation. The NCs showed high photostability and recyclability, and almost same photocatalytic activity preserved even after sixth recycle. In addition to that, the antimicrobial activity of MnO2/Al2O3 was demonstrated to be efficient in their action against the strains of gram positive and gram negative bacteria than that of the individual MnO2 and Al2O3 NPs. Thus, this multifunctional MnO2/Al2O3 can be used as an efficient candidate for the photocatalytic degradation of toxic dyes and an antimicrobial agent.

Ternary nanocomposite ZnO-g–C3N4–Go for enhanced photocatalytic degradation of RhB

The degradation of organic dyes and other pollutants has always been one of the great challenges facing mankind today. So our work designed and improved a novel composite, by using zinc oxide (ZnO) nanoparticles to modify porous carbon nitride (g-C 3 N 4 ), and then load graphene oxide (Go) nanosheets. These prepared binary and ternary composites with different weight ratios were subjected to a series of tests. The results showed that when the weight ratio of g-C 3 N 4 was 40%, the binary composite ZnO-g-C 3 N 4 transferred its absorption edge to lower energy and had the best photocatalytic performance. Moreover, the addition of Go immensely cut down the recombination of photo-generated carriers and enhanced the absorption in the visible light range. The ZnO-g-C 3 N 4 (40%)-Go (15%) displayed 98% degradation efficiency in 100 min, the rate was about 2.23 times than ZnO-g-C 3 N 4 (40%). XRD, XPS, TEM proved the successful hybridization of the composite, and PL explained the causes for the amendment of photocatalytic efficiency. The conduction band and valence band potential of the material were calculated by VB-XPS, and combined with the free radical capture experiment proved the most effective free radical in this experiment and proved the reaction mechanism of the photocatalytic reaction. Through the photocurrent and EIS the results analyzed the high responsivity of the material and the low photogenerated e − /h + recombination rate. In brief, the interface effect and synergistic effect of the ternary heterojunction greatly enhanced the photocatalytic degradation of toxic dyes. • The sample prepared by hydrothermal method has good photocatalytic performance. • The reasons for the increase of photocatalytic activity were analyzed. • The supported photocatalyst was prepared to obtain good recoverability. • Possible photocatalytic mechanism and degradation pathway of RhB by ZnO-g–C 3 N 4 –Go were proposed. • We used VB-XPS combined with the reaction potential of various free radicals to infer the most effective free radicals.

Green synthesis of Fe-doped Ag-loaded reduced graphene oxide ternary nanocomposite for efficient photocatalytic degradation of toxic dyes

The green synthesis of iron nanoparticles (FeNPs) doped and silver nanoparticles (AgNPs) loaded reduced graphene oxide (rGO) (Fe-Ag@rGO) nanocomposite and its applications in methylene blue (MB), malachite green (MG), rhodamine B (RB) degradation were reported. Initially, AgNPs loaded rGO (Ag@rGO) nanocomposites were synthesised simultaneously by an ecological method using Tamarindus indica shell extract as a green reducing agent. Then, the doping of FeNPs into rGO@Ag nanocomposites afforded Fe-Ag@rGO nanocomposite. Interestingly, the finding of this study confirmed that the Fe-Ag@rGO nanocomposites exhibited countless stupendous features in terms of dye degradation. Briefly, the UV-visible spectroscopy and Fourier-transform infrared spectroscopy (FTIR) study confirmed the synthesis of Fe-Ag@rGO nanocomposite. The scanning electron microscopy (SEM) images showed the spherical shape with cross-linked network structures that confirmed the surface modification and synthesis of Fe-Ag@rGO nanocomposite. Finally, the dye degradation potential of the photocatalyst was found to be 97.20%, 98.43%, and 97.33%, for MB, MG, RB, respectively. Herein, the improved photocatalytic performance of the Fe-Ag@rGO was found due to the larger surface area, porous nature, high electron mobility, and synergistic effect of the Fe-Ag@rGO nanocomposite. Additionally, the effective interfacial hybridisation of ‘Ag’, and doping of ‘Fe’ on the rGO sheet extended the duration of the photogenerated electron (e-) hole pairs that can also be contributing to dye degradation. Conclusively, the present experiment provides the new Fe-Ag@rGO nanocomposite to the dye degradation, which could be improved environmental remediation.

Mesoporous Octahedron-Shaped Tricobalt Tetroxide Nanoparticles for Photocatalytic Degradation of Toxic Dyes.

The present article reports a facile approach to fabrication of mesoporous octahedron-shaped tricobalt tetroxide nanoparticles (Co3O4 NPs) with a very narrow size distribution for eco-friendly remediation of toxic dyes. Co3O4 NPs were fabricated by a sol–gel process using cobalt chloride hexahydrate (CoCl2·6H2O) and monosodium succinate (C4H5O4Na) as a chelating/structure-directing agent and sodium dodecyl sulfate as a surfactant. Moreover, the phase structure, elemental composition, and thermal and morphological facets of Co3O4 NPs were investigated using XRD, FT-IR, EDS, Raman, XPS, TGA, SEM, and TEM techniques. The face-centered cubic spinel crystalline structure of the Co3O4 NPs was confirmed by XRD and SEM, and TEM analysis revealed their octahedron morphology with a smooth surface. Moreover, the narrow pore size distribution and the mesoporous nature of the Co3O4 NPs were confirmed by Brunauer–Emmett–Teller measurements. The photocatalytic activity of Co3O4 NPs for degradation of methyl red (MR), Eriochrome Black-T (EBT), bromophenol blue (BPB), and malachite green (MG) was examined under visible light irradiation, and the kinetics of the dye degradation was pseudo-zero-order with the rate constant in the order of MR > EBT > MG > BPB. Furthermore, the mechanism of photo-disintegration mechanism of the dye was examined by a scavenging test using liquid chromatography–mass chromatography, and its excellent photodegradation activities were attributed to the photogenerated holes (h+), superoxide (O2–) anions, and hydroxyl (·OH) radicals. Finally, the synergistic effect of the nano-interconnected channels with octahedron geometry, mesoporous nature, and charge transfer properties along with photogenerated charge separations leads to an enhanced Co3O4 photocatalytic activity.

Sugarcane bagasse-facilitated benign synthesis of Cu2O nanoparticles and its role in photocatalytic degradation of toxic dyes: a trash to treasure approach

The global water situation is highly challenging and requires immediate attention. It is pertinent to explore opportunities in wastewater treatment with an environment friendly route. An efficient method can be explored where biogenic nanoparticles (NPs) synthesized by agricultural waste can further enhance its potential in cleaning the environment. Therefore, a green, surfactant-free and sustainable approach towards the genesis of cuprous oxide (Cu2O) was attempted. Cu2O NPs were synthesized using Fehling’s solution and sugarcane bagasse extract which plays a vital role both as reducing and capping agent. The Cu2O NPs were characterized using Fourier transform infrared and UV–Visible spectroscopy, and their morphology was determined by high-resolution X-ray diffraction, transmission electron microscope and scanning electron microscope analysis. Their optical properties, i.e., band gaps, were calculated, and the catalytic efficiency was studied by carrying out the degradation of organic dyes [methyl orange (MO), methyl blue (MB), methyl red (MR) and Congo red (CR)] present in wastewater via spectrophotometric measurements. Simultaneously, their increasing order of degradation efficiency was found to be MR < CR < MB < MO. The mechanism of degradation of organic dyes on the surface of Cu2O NPs was also proposed. Utilizing the agricultural waste and trapping the reducing property of its polysaccharides components in facilitating the designing of the Cu2O NPs are a novel methodology. The current study envisages a new perspective for the purpose of environmental remediation and novel applications in photocatalysis.

TiO2 nanofibres decorated with green-synthesized PAu/Ag@CQDs for the efficient photocatalytic degradation of organic dyes and pharmaceutical drugs.

Organic pollutants such as dyes and pharmaceutical drugs have become an environmental menace, particularly in water bodies owing to their unregulated discharge. It is thus required to develop an economically viable and environment-friendly approach for their degradation in water bodies. In this study, for the first time, we report green route-synthesized plasmonic nanostructures (PM-CQDs (where M: Au and Ag)) decorated onto TiO2 nanofibers for the treatment of toxic dye- and pharmaceutical drug-based wastewater. PM-CQDs are efficaciously synthesized using carbon quantum dots (CQDs) as the sole reducing and capping agent, wherein CQDs are derived via a green synthesis approach from Citrus limetta waste. The characteristic electron-donating property of CQDs played a key role in the reduction of Au3+ to Au0 and Ag+ to Ag0 under visible light irradiation to obtain PAu-CQDs and PAg-CQDs, respectively. Thus, the obtained CQDs, PAu-CQDs, and PAg-CQDs are loaded onto TiO2 nanofibers to obtain a PM-CQD/TiO2 nanocomposite (NC), and are further probed via transmission electron microscopy, scanning electron microscopy and UV-visible spectrophotometry. The degradation of organic pollutants and pharmaceutical drugs using methylene blue and erythromycin as model pollutants is mapped with UV-vis and NMR spectroscopy. The results demonstrate the complete MB dye degradation in 20 minutes with 1 mg mL−1 of PAu-CQD/TiO2 NC, which otherwise is 30 minutes for PAg@CQD/TiO2 dose under visible light irradiation. Similarly, the pharmaceutical drug was found to degrade in 150 minutes with PAu-CQD/TiO2 photocatalysts. These findings reveal the enhanced photocatalytic performance of the green-synthesized Au decorated with TiO2 nanofibers and are attributed to the boosted SPR effect and aqueous-phase stability of Au nanostructures. This study opens a new domain of utilizing waste-derived and green-synthesized plasmonic nanostructures for the degradation of toxic/hazardous dyes and pharmaceutical pollutants in water.