Degradation Of Crystal Violet Dye Research Articles

Physical investigations on undoped and Fluorine doped SnO2 nanofilms on flexible substrate along with wettability and photocatalytic activity tests

A successful deposition of undoped and Fluorine doped tin oxide (TO and FTO) nano films at relatively low temperature 250°C on flexible substrate (Polyethyerimide) was obtained using the spray pyrolysis technique. The Fluorine doping effects on the structural, morphological and optical properties were investigated. XRD measurements permit textural characterization, and show that the films have a tetragonal polycrystalline structure. The increase of crystalline size and reduction of defects and strain with Fluorine doping improve the crystalline quality. This is may be due to the substitution of O−2 by F-. Furthermore, the structural changes of the films affected the surface roughness which became rough with the Fluorine. This was confirmed by wettability measurements. Moreover, the gap energy exhibits a slight red-shift with F-doping. The photoluminescence spectra showed that Fluorine doping increased the radiative centers, which is confirmed by structural results. The photocatalytic performance of TO and FTO nanofilms were investigated by degradation of crystal violet dye under UV radiations. Results showed that TO and FTO exhibit high photocatalytic activities, which can be enhanced by H2O2 addition.

ZnO nanonails for photocatalytic degradation of crystal violet dye under UV irradiation

In this study, nanonails-like zinc oxide (ZnO) nanostructures were synthesized in large quantity by thermal evaporation technique and further characterized in detail using different techniques such as field emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM), X-ray diffractometer (XRD), UV-visible spectroscopy, photoluminescence (PL) spectroscopy, and Raman spectroscopy. Morphological characterizations revealed that the as-synthesized nanostructures possess nail-like geometry, grown in large quantity. The XRD, UV-visible absorbance spectra, PL, and Raman spectra confirms good crystallinity and optical property of as-synthesized ZnO nanonails. The photocatalytic activities of designed nanostructures for crystal violet dye (CV-dye) degradation was evaluated under UV illumination and monitored by UV-vis spectroscopy at different time intervals until the dye was completely degraded to colorless end product. A fast decomposition was observed with ~95% degradation rate within the initial 70 min, which is attributed to high specific surface area (56.8 m2/g), high crystallinity and better optical property of ZnO nanonails.

Microbial decolorization and degradation of crystal violet dye by Aspergillus niger

Two fungi were isolated and examined to decolorize crystal violet dye, frequently used as textile dye and in microorganism staining, using basal salt medium under static condition at 30 °C. The more effective fungus gave less dry weight and lower pH indicating that the process was directed toward the decolorization process giving acidic products rather than microbial growth. The effective fungus was identified as Aspergillus niger and was used in the rest of experiments. Increasing the incubation period more than 10 days did not improve the decolorization process, while the best pH was 5.5. The decolorization process was effective (up to 84.6 %) with the examined range of dye concentrations (10–40 ppm). Sucrose content, as a carbon source, more than 1 % did not improve the decolorization process (80.9 %). Using ammonium sulfate as a nitrogen source, instead of sodium nitrate in the original basal medium, lowered the decolorization process, while using corn steep liquor enhanced the biodegradation up to 96.1 %. Although the dye violet color vanishes in acid medium because of decreasing the possibility of extending the benzene chromophore as a result of binding the nitrogen lone pair in the ammonium ion, the UV–Vis spectra and LC–MS–ESI analysis of the bioassay products proved that the decolorization is due to the biodegradation of the dye rather than the resonance factor in acidic medium or biosorption by fungus mycelia.

Influence of jute template on the surface, optical and photocatalytic properties of sol-gel derived mesoporous zinc oxide

Utility of bio-templates in the synthesis of crystalline solids is one of the preferred routes in green synthesis. The present study explores jute fiber as a biotemplate for the sol-gel synthesis of zinc oxide. AT-IR of the as synthesized sample clearly revealed the chelation between the metal and active groups of jute. The surface area enhancement and reduction in crystallite size in the templated samples were confirmed from BET and XRD analyses. ZnO prepared using 0.5g/3g of precursor possessed higher average crystallite size than the other samples. Surprisingly, the same sample also had a high surface area due to its distinct spherical morphology, highlighting the influence of morphology on the surface area of ZnO. Jute templated ZnO exhibited significant photocatalytic activity for degradation of crystal violet dye under visible light. Thus, jute has been proved to be an efficient template for the sol-gel synthesis of ZnO with controlled crystallite characteristics.

Bandgap-tailored NiO nanospheres: an efficient photocatalyst for the degradation of crystal violet dye solution

Bandgap-tailored NiO nanospheres were successfully synthesized by facile precipitation method for the first time and characterized by XRD, EDX, SEM, TEM, FTIR, UV and PL. Interestingly, the modification of the band gap was observed using UV–Vis (DRS) spectroscopy, and the observed band gap is 3.31 eV. The morphology of the materials was analysed by SEM and TEM which show the sphere like structures of NiO with the particle size of ~20 nm. The efficiency of the materials was examined by the degradation of crystal violet dye under UV light illumination. The complete degradation was achieved within 60 min, and the mechanism of the degradation were also been proposed. In addition, the degradation of rhodamine B (RhB) and methylene blue dye solution was also carried out to extend the practical applications of NiO nanospheres. The involvement of reactive oxidative species (ROS) was found out by trapping experiment, and the ROS is superoxide radical anion.

Titanium aminophosphates: synthesis, characterization and crystal violet dye degradation studies

Titanium aminophosphates are prepared using titanium tetraisopropoxide, orthophosphoric acid and aliphatic amines. Their detailed characterization and catalytic crystal violet dye degradation were studied.

Correction: Titanium aminophosphates: synthesis, characterization and crystal violet dye degradation studies

Correction for ‘Titanium aminophosphates: synthesis, characterization and crystal violet dye degradation studies’ by Anumula Rajini et al., RSC Adv., 2016, 6, 507–514.

Chemical and Photocatalytic Degradation of Crystal Violet Dye by Indian Edible Chuna (Calcium Oxide/Hydroxide)

Chemical and Photocatalytic Degradation of Crystal Violet Dye by Indian Edible Chuna (Calcium Oxide/Hydroxide)

Preparation and Characterization of Polyhedral Oligomeric Silsesquioxane-Containing, Titania-Thiol-Ene Composite Photocatalytic Coatings, Emphasizing the Hydrophobic-Hydrophilic Transition.

Coatings prepared from titania-thiol-ene compositions were found to be both self-cleaning, as measured by changes in water contact angle, and photocatalytic toward the degradation of an organic dye. Stable titania-thiol-ene dispersions at approximately 2 wt % solids were prepared using a combination of high-shear mixing and sonication in acetone solvent from photocatalytic titania, trisilanol isobutyl polyhedral oligomeric silsesquioxane (POSS) dispersant, and select thiol-ene monomers, i.e., trimethylolpropane tris(3-mercaptopropionate) (TMPMP), pentaerythritol allyl ether (APE), and 1,3,5-triallyl-1,3,5-triazine-2,4,6(1H,3H,5H)-trione (TTT). The dispersed particle compositions were characterized by DLS and TEM. The synthetic methods employed yield a strongly bound particle/POSS complex, supported by IR, 29Si NMR, and TGA. The factors of spray techniques, carrier solvent volatility, and particle size and size distributions, in combination, likely all contribute to the highly textured but uniform surfaces observed via SEM and AFM. Polymer composites possessed thermal transitions (e.g., Tg) consistent with composition. In general, the presence of polymer matrix provided mechanical integrity, without significantly compromising or prohibiting other critical performance characteristics, such as film processing, photocatalytic degradation of adsorbed contaminants, and the hydrophobic-hydrophilic transition. In all cases, coatings containing photocatalytic titania were converted from superhydrophobic to superhydrophilic, as defined by changes in the water contact angle. The superhydrophilic state of samples was considered persistent, since long time durations in complete darkness were required to observe any significant hydrophobic return. In a preliminary demonstration, the photocatalytic activity of prepared coatings was confirmed through the degradation of crystal violet dye. This work demonstrates that a scalable process can be found to prepare titania-thiol-ene coatings having improved coating properties which also exhibit photocatalytic and self-cleaning attributes.

Template-free synthesis of Fe3O4 nanorod bundles and their highly efficient peroxidase mimetic activity for the degradation of organic dye pollutants with H2O2

The high surface to volume ratio of Fe3O4 nanorods facilitates the excellent activation of H2O2 for the photo-Fenton-like degradation of crystal violet dye under solar light.

UV–Visible light induced photocatalytic studies of Cu doped ZnO nanoparticles prepared by co-precipitation method

Undoped and Copper (Cu) doped zinc oxide (ZnO) (Zn1−xCuxO, x=0.01, 0.02, 0.03, 0.04 and 0.05) nanoparticles (NPs) capped with (1.0%) Thioglycerol (TG) have been successfully synthesized by co-precipitation method. The synthesized samples have been characterized by X-ray diffraction (XRD), Energy dispersive spectroscopy (EDS), Transmission electron microscopy (TEM), Photoluminescence (PL) and UV–Visible spectroscopy. Incorporation of impurity ions in pure ZnO NPs leads to a shift the spectra for both excitation and emission to visible region as compared to pure ZnO. The photocatalytic activity of undoped and Cu doped ZnO photocatalyst were investigated by the degradation of Crystal Violet (CV) dye in aqueous medium under exposure of UV–Visible light irradiations. Firstly, degradation of CV dye has been studied with TG capped, undoped and Cu doped ZnO NPs synthesized at pH-8.0. From the results, it has been found that Cu doping concentration of 3.0% is optimal for higher photophysical and photocatalytic properties. When pH of optimum doped NPs was varied from 8.0 to 10.0, 78.7% to 96.5% of CV dye has been degraded after 3.5h. Further increasing the pH to 12.0 for optimum doped NPs, 100% dye degrades in 2.5h. This shows that the doping and pH has a pronounced effect on the photocatalytic activity of ZnO NPs. Loading of catalyst shows maximum photodegradation of CV dye at 3.0g/L of Cu (3.0%) doped ZnO at pH-12.0 for 10mg/L of CV dye. Kinetic studies shows that photo degradation of CV follow a pseudo first-order kinetic law. The reason for enhanced degradation with Cu doped NPs in comparison to undoped NPs has been described and discussed in this work.

D-Pencillamine assisted microwave synthesis of Bi2S3 microflowers/RGO composites for photocatalytic degradation—A facile green approach

Bismuth sulphide (Bi2S3)/reduced graphene oxide (RGO) composites were fabricated using facile single step process using d-pencillamine as a sulphur source. Fourier Transformer Infra Red spectroscopy (FT-IR), X-Ray Diffraction (XRD), Raman Spectroscopy, Scanning Electron Microscopy (SEM), High Resolution Transmission Electron Microscopy (HR-TEM), and Electrochemical Impedance Spectroscopy (EIS) were employed to characterize and evaluate the properties of Bi2S3/RGO composites. This paper delivers a systematic investigation on the incorporation of the RGO on Bi2S3 microflowers for high efficiency visible light photocatalytic degradation of crystal violet dye (CV). As synthesized Bi2S3 microflower/RGO composites show tremendous improved photocatalytic performance than pure Bi2S3 microflowers. The superior photocatalytic activity of the Bi2S3/RGO composite was due to the enhanced light absorption, reduced recombination rate, and efficient charge transfer by incorporation of RGO. The degradation efficiency of Bi2S3/RGO 3% shows higher photocatalytic activity than pure Bi2S3 and commercialized TiO2.

Rapid photocatalytic degradation of crystal violet dye over ZnO flower nanomaterials

A simple solution method was employed for the direct synthesis of ZnO-flowers using zinc acetate precursor in basic medium and utilized as photocatalyst for the degradation of crystal violet (Cv) dye. Each ZnO-flower was comprised of well-defined petals with the average length of ∼300±50nm. The photocatalytic activity of ZnO-flowers was elucidated towards the degradation of Cv-dye under light illumination. The as-synthesized ZnO-flowers showed very fast degradation of Cv-dye with the degradation rate of ∼96% within the time interval of 80min. Mineralization of the dye was extensively described by investigating the mass spectroscopy of the dye before and after the photocatalytic reaction.

Sol–gel synthesis of Sm2InTaO7 and its photocatalytic activity on degradation of crystal violet dye and reduction of Cr(VI) ions

This paper reports the synthesis of Sm2InTaO7 and its photocatalytic activity on the degradation of crystal violet dye and reduction of Cr(VI) ions in aqueous solution. Sm2InTaO7 was prepared by sol–gel method at 1,200 °C. For comparison purposes, Sm2InTaO7 was prepared also by solid-state reaction at 1,400 °C. The evolution of the crystalline phases of the sol–gel sample with the annealing temperature was followed by X-ray diffraction. The cubic crystalline structure of Sm2InTaO7 was determined by Rietveld refinement method. Specific surface area was 5 m2g−1 for sol–gel sample and 1 m2g−1 for solid-state sample, whereas energy band gap was around 3.5 eV. Sm2InTaO7 prepared by sol–gel method showed better photocatalytic activity than Sm2InTaO7 prepared by solid-state reaction for the mineralization of crystal violet dye and reduction of Cr(VI) solution under UV-light irradiation.

Ultrasound assisted synthesis of doped TiO2 nano-particles: Characterization and comparison of effectiveness for photocatalytic oxidation of dyestuff effluent

The present work deals with the synthesis of titanium dioxide nanoparticles doped with Fe and Ce using sonochemical approach and its comparison with the conventional doping method. The prepared samples have been characterized using X-ray diffraction (XRD), FTIR, transmission electron microscopy (TEM) and UV–visible spectra (UV–vis). The effectiveness of the synthesized catalyst for the photocatalytic degradation of crystal violet dye has also been investigated considering crystal violet degradation as the model reaction. It has been observed that the catalysts prepared by sonochemical method exhibit higher photocatalytic activity as compared to the catalysts prepared by the conventional methods. Also the Ce-doped TiO2 exhibits maximum photocatalytic activity followed by Fe-doped TiO2 and the least activity was observed for only TiO2. The presence of Fe and Ce in the TiO2 structure results in a significant absorption shift towards the visible region. Detailed investigations on the degradation indicated that an optimal dosage with 0.8 mol% doping of Ce and 1.2 mol% doping of Fe in TiO2 results in higher extents of degradation. Kinetic studies also established that the photocatalytic degradation followed the pseudo first-order reaction kinetics. Overall it has been established that ultrasound assisted synthesis of doped photocatalyst significantly enhances the photocatalytic activity.

Structural, Optical and Photocatalytic Properties of Sol–Gel Synthesized Mesoporous TiO<SUB>2</SUB> Film

TiO2 surfactant-templated nanostructured film was fabricated by supramolecular templating technique using TiCl4 and P-123 as raw material and surfactant, respectively. The film was produced by sol-gel dip coating procedure. Characterization of the product was carried out by means of X-ray diffraction (XRD), scanning electron microscopy (SEM), Brunauer-Emmett-Teller (BET) specific surface areas, thermogravimetry (TG), and UV-vis absorption spectroscopy. Detailed characterization reveals that film is transparent and has a wormlike mesostructured with high surface area. It is about 2 microm thick and is composed of closely packed anatase particles. The estimated band gap value of TiO2 thin film in the present work is 3.69 eV which is about 0.3 eV larger than value reported in literature for anatase thin film. It could be due to quantum size effect arising from the small size of TiO2 nanocrystallite in this thin film. The photocatalytic activity of the prepared TiO2 film was evaluated by Crystalviolet dye degradation. The film has excellent photocatalytic efficiencies and more than 70% of dye was decolorized in 60 minutes.

Degradation pathways of crystal violet by Fenton and Fenton-like systems: Condition optimization and intermediate separation and identification

The main advantage of Fenton's reagent (FR) over other OH systems is its simplicity. FR has the potential for widespread use in treating wastewater, but compared to other OH systems, little information on the dye degradation pathways of FR exists. The degradation of crystal violet (CV), a triphenylmethane dye, by FR was determined as a function of reagent concentration and ratio and pH in the batch treatment. The experimental results showed the optimum Fe 2+/H 2O 2 ratio to be 0.5 mM:50 mM and the optimum Fe 3+/H 2O 2 ratio to be 1 mM:50 mM. Optimal pH was about 3. To obtain a better understanding of the mechanistic details of Fenton reagent's degradation of CV dye, the intermediates of the process were separated, identified, and characterized by HPLC–PDA-ESI-MS and GC–MS techniques in this study. Indications were that the probable degradation pathways were N-de-methylation and cleavage of the conjugated chromophore structure. The intermediates were generated in the order of the reaction time and relative concentration, indicating that the N-de-methylation degradation of CV dye is a major reaction pathway. The reaction mechanisms proposed in this research should prove useful for future application of the technology to the decolorization of dyes.