Photocatalytic Degradation Of Crystal Violet Research Articles

Recycled gold-reduced graphene oxide nanocomposite for efficient adsorption and photocatalytic degradation of crystal violet

In this study, gold-reduced graphene oxide (Au@rGO) nanocomposite has been synthesized by repurposing electronic waste and dry batteries. This innovative approach involved utilizing the graphite rod from dry batteries to produce reduced graphene oxide (rGO), which was subsequently modified through the incorporation of gold nanoparticles obtained from recycled electronic waste. This methodology marks a significant breakthrough in electronic waste recycling, presenting a cost-effective and sustainable means of creating novel nanocomposites for applications in photocatalysis and adsorption, particularly in the removal of crystal violet (CV) from aqueous media. The synthesized Au@rGO nanocomposite was characterized using X-ray diffraction, scanning electron microscopy, energy dispersed X-ray, and N2 adsorption/desorption. Parameters that affect the adsorption and photocatalytic degradation of CV dye have been studied in detail. The optimal conditions for CV adsorption and photocatalytic degradation were pH of 10, equilibrium time of 30 min, CV concentration of 10 mg/L and adsorbent dosage of 40 mg. Furthermore, the isotherm and kinetics of CV removal were also studied. The removal of CV dye using adsorption and photocatalytic degradation techniques reached 95% and 99%, respectively. Consequently, the results showed that photocatalytic degradation of CV dye onto the mesoporous Au@rGO nanocomposite is more proper way than the adsorption technique for removing the CV dye from aqueous media. The designed photocatalyst has high efficiency and it can be reused and activated several times so it can be used in real water treatment applications.

New Y0.045Ni0.045Fe2.91O4 nanowires decorated over mesoporous silica for crystal violet removal: Response surface methodology optimization, kinetics, and isothermal studies

Recently, there has been considerable interest in developing an efficient, easily separable, cost-effective, and environmentally friendly catalyst for treating toxic environmental pollutants. In this study, we successfully designed yttrium–nickel-doped magnetite nanowires (Y0.045Ni0.045Fe2.91O4) and their mesoporous silica (MS)-coated composite (Y0.045Ni0.045Fe2.91O4/MS) using a simple coprecipitation method. The resulting composite demonstrated effective adsorption and photocatalytic degradation of crystal violet (CV) dye under sunlight. Various instrumental characterization techniques were employed to assess the nanowires' morphological, chemical, and surface functional properties and their composite. The existence of metal–oxygen bonds in Y0.045Ni0.045Fe2.91O4 within the 500–800 cm−1 range was verified through FTIR analysis. According to the Brunauer–Emmett–Teller analysis, the composite exhibited a surface area of 285 m2/g, a pore volume of 0.436 cm³/g, and an average pore width of 5 nm. The composite's high surface area and mesoporous nature underscored its porous structure, confirming its enhanced adsorption capacity for contaminants. High resolution XPS spectrum justified the presence of surface silanol groups (Si–OH) which are responsible for adsorption phenomena. Photocatalytic experiments revealed that Y0.045Ni0.045Fe2.91O4 nanowires and their composites achieved 89% and 90% degradation rates for CV dye within 60 and 10 min, respectively. The removal efficiency was assessed under optimized conditions of pH (8), dose (15 mg), time (60 and 10 min), and concentration (10 mg/L). Statistical analysis revealed that pH significantly impacted CV dye removal because functional group activation varied at different pH values. To elucidate the adsorption mechanism and kinetics, the Temkin isotherm model and pseudo-second-order kinetics model (R2 = 1.996 mg min−1) were the best fit for the composite. Furthermore, approximately 99% of the nanowires were magnetically separated from the reaction mixture in an external magnetic field. The demonstrated synergy of efficient adsorption–photocatalysis, coupled with easy recovery, suggests that innovatively designed nanomaterials are optimal for the water remediation of organic pollutants in wastewater.

Photocatalytic Degradation of Crystal Violet Using SnO2/ZnO Nanocomposite Synthesized by Facile Sol-Gel Method

Photocatalytic Degradation of Crystal Violet Using SnO2/ZnO Nanocomposite Synthesized by Facile Sol-Gel Method

Fabrication of Ru loaded MgB2 with guar gum hybrid for photocatalytic degradation of crystal violet

Today, dyes/pigment-based materials are confronting a serious issue in harming marine ecology. Annihilate these serious water pollutants using photoactive 2D nanohybrid catalysts showed promising comparativeness over available photocatalysts. In the present work, a facile route to decorate Ruthenium (Ru) on 2D MgB2 flower-like nanostructures was developed via ecofriendly guar gum biopolymer substantial template (MgB2/GG@Ru NFS) and its photocatalytic performance was reported. Synthesis of MgB2@Ru, MgB2/GG@Ru NFS and commercial MgB2, was studied by FTIR, XRD, FE-SEM, EDX, AFM, TEM, UV–vis spectra, and XPS analysis. From the results, the MgB2/GG@Ru NFS exhibited a superior photocatalytic performance (99.7 %) than its precursors MgB2@Ru (79.7 %), and MgB2 (53.7 %), with the degradation efficiency of the crystal violet (CV) within 100 min under visible light irradiation. The proposed photo-catalyst MgB2/GG@Ru NFS showed negligible loss of photocatalytic activity even after five successive cycles, revealing its reusability and enhanced stability due to the network structure. The photocatalytic mechanism for MgB2/GG@Ru NFS was evaluated by trapping experiment of active species, verifying that superoxide (O2−) and electron (e−) contributed significant role in the dye degradation.

Comparative Study of the Photocatalytic Degradation of Crystal Violet Using Ferromagnetic Magnesium Oxide Nanoparticles and MgO-Bentonite Nanocomposite

In this work, the exploitation of the synthesized magnesium oxide nanoparticles and MgO-bentonite nanocomposite as an effective photocatalyst has been reported. They were utilized to study their applicability for the photocatalytic degradation of crystal violet in wastewater. Fourier-transform infrared (FTIR) spectra, X-ray powder diffraction (XRPD), energy-dispersive X-ray spectroscopy (EDX), and transmission electron microscope (TEM) were used for characterization. The photocatalytic efficiency of the synthesized photocatalysts for CV decomposition has been optimized in terms of several factors such as pH, contact time, the dose of the catalyst, and the dye concentration. The maximum degradation efficiency of CV was found to be 99.19% at the optimum state of pH value of 7, using 0.2 g of MgO NPs, while in the case of MgO-bentonite nanocomposite, the maximum degradation efficiency was decreased to 83.38%. The photocatalytic reaction mechanism was investigated using the scavenging reaction process, revealing that holes were majorly responsible for the degradation of CV. The kinetic data were suitable and best fitted by the pseudo-first-order kinetic model.

The highly efficient green synthesis of nanostructured ZnFe2O4 photocatalysts by using Ziziphus mauritiana and Salvadora persica extracts for the photocatalytic degradation of crystal violet in sunlight

The current study is aimed to investigate the photocatalytic degradation of crystal violet dyes solution in the presence of modified ZnFe2O4 photocatalysts by Ziziphus mauritiana and Salvadora persica extracts in sunlight. Regardless of the extracts used, the modified ZnFe2O4 catalysts demonstrated excellent photocatalytic degradation. However, the catalysts modified using Salvadora persica extract achieved superior photocatalytic degradation of crystal violet dye. ZnFe2O4 with Salvadora persica yielded smaller particles with a larger surface area, smaller band gap energy and a better distribution of differently sized particles than by using Ziziphus mauritiana. This photocatalyst also demonstrated stability, being able to be reused at least five times with minimal loss of catalytic ability, falling from 91% at the first iteration to 85% by the fifth reuse. These materials were prepared easily using an environmentally friendly method.

Photocatalytic degradation of crystal violet and benzimidazole using Ag-CoFe2O4 and its composite with graphitic carbon nitride

Photocatalytic degradation of crystal violet and benzimidazole using Ag-CoFe2O4 and its composite with graphitic carbon nitride

A feasibility study on the green synthesis of iron oxide nanoparticles using Chlorella vulgaris extract for photocatalytic degradation of crystal violet

Iron oxide nanoparticles have recently been proposed as an efficient and environmentally friendly material for wastewater treatment. In comparison to chemical and physical approaches, green nanoparticles synthesis method that employs microalgae or plant extract is regarded as more cost-effective and environmentally friendly. In this study, iron oxide nanoparticles were synthesised using Chlorella vulgaris extract, and their feasibility in removing crystal violet dye from wastewater via photocatalytic degradation was investigated. Iron oxide nanoparticles was synthesized by adding C. vulgaris extract to 0.1 M iron (III) chloride solution. The X-ray diffraction (XRD) peaks revealed that the iron oxide nanoparticles were crystalline in nature. The nanoparticles were also analysed using Field Emission Scanning Electron Microscope (FESEM), revealing a sphere with cylindrical shape of about 109 nm in size, with the Energy Dispersive X-ray (EDX) elemental analysis showing the highest proportion of O followed by Fe. The ability of iron oxide nanoparticles to remove crystal violet dye in the dark and in the presence of ultraviolet (UV) light was investigated. The percentage removal was consistently higher under the presence of UV lamp at all durations tested (30 – 90 minutes), indicating the feasibility of iron oxide nanoparticles to photodegrade crystal violet dye.

Synthesis of Pr3+-doped WO3 particles: correlation between photoluminescent and photocatalytic properties.

The WO3 and WO3:Pr3+ particles were successfully synthesized by the co-precipitation method. The XRD analysis with Rietveld refinement revealed the formation of a monoclinic phase for WO3 and for doped samples, this result was later confirmed by Raman spectroscopy studies. The presence of Pr3+ in the WO3 crystalline lattice induced structural and optical changes in the particles, increasing the crystallite size, distorting the clusters (shortening of the W-O bonds), favoring the crystallinity and changing the optical gap. The predominant morphology of the particles of WO3 and WO3:Pr3+ obtained was nanocubes constituted by the superposition of plates of nanometric thicknesses. The photoluminescence of WO3 and WO3:Pr3+ was produced by the existence of surface defects in the particles. The increase in the concentration of Pr3+ promoted an increase in the intensity of PL, due to the increase in the rate of recombination of electron/hole charges. The WO3 sample exhibited emission in the white region due to the adjustment of simultaneous electronic transitions in the blue, green and red regions, characteristic of the broadband spectrum. The interval of the 2.65 eV gap band and the high efficiency in the separation of the photogenerated charges (e-/h+) with the low recombination rate contributed to the photocatalytic degradation of Crystal Violet (CV) by the catalyst. The WO3:4% Pr3+ sample showed the best photocatalytic efficiency, degrading 73% of the CV dye in 80 minutes. This result was associated with a reduction in particle size and density of oxygen vacancies on the material surface.

Hydrothermal Synthesis and Photocatalytic Performance of Barium Carbonate/Tin Dioxide Nanoparticles

Background: Crystal violet dye is stable and difficult to be biodegraded owing to the existence of the multiple aromatic rings of the crystal violet molecules. Removing crystal violet dye from the wastewater is a major challenge. Objective: The aim of the research is to synthesize barium carbonate/tin dioxide nanoparticles and investigate the photocatalytic performance for the degradation of crystal violet. Methods: Barium carbonate/tin dioxide nanoparticles were synthesized via a facile hydrothermal route without any surfactants. The crystal structure, micro-morphology, size and optical performance of the barium carbonate/tin dioxide nanoparticles were investigated by powder X-ray diffraction, scanning electron microscopy, transmission electron microscopy and solid ultraviolet-visible diffuse reflectance spectrum. Results : The size of the barium carbonate/tin dioxide nanoparticles is 20 nm to 200 nm with the band gap of 3.71 eV. The photocatalytic activity of the barium carbonate/tin dioxide nanoparticles was measured by the photocatalytic degradation of crystal violet. The crystal violet degradation efficiency reaches 92.1% with the ultraviolet-visible irradiation time of 8 h using 10 mg barium carbonate/tin dioxide nanoparticles. The crystal violet degradation ratio increases to 96.1% when the dosage of the barium carbonate/tin dioxide nanoparticles increases to 20 mg/10 mL crystal violet dye solution. Active species capture photocatalytic experiments showed that the holes, hydroxyl radicals and superoxide ion radicals are the main active species. Reusability experiments displayed that the barium carbonate/tin dioxide nanoparticles are stable for the crystal violet dye degradation. Conclusion: The barium carbonate/tin dioxide nanoparticles show good photocatalytic performance toward crystal violet under ultraviolet light irradiation.

Photocatalytic degradation of crystal violet on titanium dioxide/graphene aerogel doped sulfur

In this study, titanium dioxide/graphene aerogel doped sulfur (S-TiO2/GA) was successfully synthesized by the coprecipitation method with the precursors including titanium isopropoxide, graphene oxide, and thiourea. The S-TiO2/GA material was characterized by different advanced analysis methods. The doping between titanium dioxide (TiO2) and S increased the degree of anatase, reduced the bandgap energy, and enhanced the absorption and photoactivity of the S-TiO2/GA material. The degradation efficiency was evaluated via crystal violet (CV) under UV light illumination. The effects of five parameters such as (1) photocatalyst dosage, (2) pH, (3) CV concentration, (4) Adsorption time, and (5) irradiation time, were investigated by the Plackett-Burman and Box-Behnken models to select the optimal conditions for the CV degradation process of the S-TiO2/GA material. Besides, the mineralization of the S-TiO2/GA was evaluated via the total organic carbon parameter. The dominant free radical for the photodegradation of CV was also found. The aforementioned results also confirmed the promising applications of the material in environmental treatments.

Solution combustion synthesis of β-Cu2V2O7 nanoparticles: photocatalytic degradation of crystal violet under UV and visible light illumination

β-Cu2V2O7 nanoparticles were prepared using a solution-combustion method using two different fuels, which are: Urea and Glycine. The as-prepared catalysts were characterized using X-ray diffraction, Fourier transform infrared spectra, scanning electron microscopy, Brunauer–Emmett–Teller Method, and UV–Vis diffusive reflectance spectroscopy. The photocatalytic activity of copper vanadate was investigated by degradation of cationic dye crystal violet in an aqueous solution under UV and visible light irradiation. The effect of selected parameters such as catalyst mass, dye concentration, and solution pH on the catalytic performances has been discussed. On the other hand, the reuse tests of β-Cu2V2O7 displayed high-performance stability after five cycles.

Substitution of V5+ in BiVO4 with Ni2+ and the Improved Photocatalytic Degradation of Crystal Violet Under White LED Light Irradiation

Substitution of V5+ in BiVO4 with Ni2+ and the Improved Photocatalytic Degradation of Crystal Violet Under White LED Light Irradiation

Synthesis of mesoporous TiO2/BMMs via hydrothermal method and its potential application toward adsorption and photocatalytic degradation of crystal violet from aqueous solution

The novel mesoporous TiO 2 /BMMs nanocomposites using bimodal mesoporous silica (BMMs) as support and rutile-anatase mixed phase as active species were successfully synthesized via hydrothermal and subsequent calcination method. Their structural and physiochemical properties were characterized by X-ray diffraction, scanning/transmission electron microscopy, BET-isotherms, inductive coupled plasma optical emission spectroscopy, zeta potential, Fourier transform infrared and UV–visible spectroscopy. The results demonstrated that the photocatalytic degradation activity of the synthesized catalysts were extensively enhanced as compare to bare TiO 2 , due to the highly uniform dispersion of mixed phases (Anatase and Rutile) TiO 2 on the bimodal mesoporous surfaces. Particularly, the catalytic efficiency became increased as increasing the calcination temperature, showing the highest (98%) overall removal of CV dye using TBH5d as catalyst calcinated at 800 °C. Its most interesting finding is that the % adsorption of TBH5d was 46 %, more than that (26%) of TBH5c calcinated at 600 ℃, however, its % degradation was 21 %, lower than that (39 %) of TBH5c for dye concentration of 20 ppm in 50 min. Meanwhile, the kinetic adsorption and degradation performances were followed the pseudo second and first order models, respectively, further proving the high degradation efficiency of TBH5c with high rate constant than that of TBH5d. Thermodynamic parameters ( ΔG ads , ΔH ads , and ΔS ads ) were calculated, suggesting the spontaneous and exothermic procedure with high entropy, while the adsorption equilibrium data was fitted to Dubinin-Radushkevich model. Both TBH5c and TBH5d showed an excellent stability and reactivity 71.2 and 61 %, respectively, even after 5th cycles. Thus, these results suggested that that TBH5c may be one of the suitable candidates in wastewater treatments.

Low-temperature synthesis of hetero-structures of magnetically separable iron oxide@Au-rGO nanocomposite for efficient degradation of organic dye under visible light irradiation

In the present study, Fe3O4@Au core-shell nanoparticles decorated on reduce graphene oxide (Fe3O4@Au/rGO) nanocomposite were synthesized using the reduction method by sodium citrate, Hummer's method, and hydrothermal method, respectively. The as-prepared nanostructures were characterized by X-ray diffraction (XRD), Energy Dispersive X-ray (EDX), transmission electron microscopy (TEM), scanning electron microscopy (SEM)to assess the surface features, crystallinity and morphological characteristics. These nanostructures were employed for photocatalytic degradation of crystal violet (CV), and amongst them, Fe3O4@Au/rGO nanocomposite offered the best results under the visible light irradiation and optimal conditions. The effect of the amount of nano-photocatalyst, initial CV concentration, the initial pH, temperature, stirring speed, and degradation time was evaluated individually. A 100% degradation was obtained after 1 min in the presence of 0.008 g nano-photocatalyst, and also 100% of degradation was achieved after 5 min in the presence of 0.005 g of the prepared nano-photocatalyst. After a few tests, its photocatalytic performance was retained, implying the superior stability of Fe3O4@Au/rGO nanocomposite. The kinetic study of photocatalytic degradation also indicated that the fit model for the kinetic reaction was the pseudo-second-order kinetic model. Finally, the photocatalytic degradation of real samples with synthesized nanocomposite showed promising results.

Facile synthesis of ZnO/CuO/Ag2O ternary metal oxide nanocomposite for effective photodegradation of organic water pollutants

AbstractThe current study is focused on fabrication of a ternary metal oxide nanocomposite (ZnO/CuO/Ag2O) as an efficient and superior photocatalyst by step-wise implanting of p-type CuO and Ag2O semiconductors onto an n-type semiconductor (ZnO) via a chemical method. The structural and textural characteristics of the manufactured samples were characterized by X-ray diffraction (XRD), Fourier-transform infrared (FTIR) spectroscopy, field emission scanning electron microscopy combined with electron dispersive spectroscopy (FESEM-EDS) and UV–visible spectroscopy. The photocatalytic performance of the fabricated ternary nanocomposite was tested against the photocatalytic degradation of crystal violet (CV) and rhodamine B (RhB) organic dyes under solar light irradiation. The ternary nanocomposite demonstrated about 99.05% and 97.38% degradation efficiency toward CV and RhB dyes under solar light irradiation in a time period of 105 min. The calculated rate constants (k, min−1) for degradation under solar light over the ZnO/CuO/Ag2O nanocomposite were 4.26 and 3.61 times higher than the k value obtained over ZnO nanoparticles for CV and RhB dyes, respectively. The main reactive species taking part in the photodegradation processes were •OH and •O2− over ZnO/CuO/Ag2O photocatalysts under solar light illumination. Furthermore, the recycle experiments confirmed good reusability and photo-stability of the ZnO/CuO/Ag2O ternary nanocomposite.

Photocatalytic treatment of Crystal Violet in aqueous solution: Box–Behnken optimization and degradation mechanism

AbstractA photocatalytic degradation of Crystal Violet (CV) in aqueous solution was investigated in batch reactor. Box–Behnken experimental design was using to establish a quadratic model showing the functional relationship between degradation rate and four operational parameters: pollutant concentration, irradiation time, zinc oxide (ZnO) dose, and stirring speed, at free pH (~ 7), lamp irradiance (45 W m−2) and ambient temperature (~25°C). The results show that the most influential factor on the process was the CV concentration, with an effect of 48.27%, followed by the ZnO dose with an effect of 15.16%, at the third position comes the irradiation time with an effect of 11.81%, and the forth influencing parameter was the stirring speed with an effect of 1.04%. A total CV degradation (100%) was reached for ultraviolet (UV) irradiation time equal to 90 min, ZnO dose of 0.7 g L−1, and stirring speed of 558 rpm for CV initial concentration of 55 mgL−1. For CV concentration equal to 100 mg L−1solar irradiation seems to be better up to 96% of degradation against 62% for UV lamp after 120 min of irradiation time. The O•−2 radicals were the main active species responsible for the degradation of CV. The degradation kinetic was well described by the pseudο first‐οrder mοdel.

Tragacanth gum mediated green fabrication of mesoporous titania nanomaterials: Application in photocatalytic degradation of crystal violet

Water remediation is a crucial subject in present century. Hence, several processes have been used for this aim, which the photodegradation method with high activity, cost-effectiveness, and durability has been remarkable. In this project, the various novel mesoporous Titania nanomaterials (MTN) were green synthesized using Tragacanth gum as coupling agent. The effect of calcination times on the crystalline structure of the resulted MTNs was examined. MTNs displayed the dramatically specific surface area with negative surface charge and nano-sheet structure, and they applied for photodegradation of crystal violet under ultraviolet irradiation due to proper band gaps energy. The obtained MTN in 8 h calcination time (MTN-8) showed the best photoreduction activity. Also, the superoxide radicals, electrons, and hole pairs represented the main degradation agents as the reduction rate of crystal violet. Next, the transformation pathways were proposed, which could be transformation singlet oxygen addition, hydroxyl addition, and N-demethylation reactions.

Visible Light-Assisted Photocatalysis Using Spherical-Shaped BiVO4 Photocatalyst

In this research work, we reported the synthesis of a spherical-shaped bismuth vanadate (BiVO4) photocatalyst using a cost-effective, simple, chemical hydrothermal method and studied the effect of deposition temperatures on the structural, morphological, optical properties, etc. The XRD result confirmed the monoclinic scheelite phase of BiVO4. An XPS study confirmed the occurrence of Bi, V, and O elements and also found that Bi and V exist in +3 and +5 oxidation states, respectively. SEM micrographs revealed the spherical-shaped morphology of the BiVO4 photocatalyst. Optical investigation showed that the bandgap of the BiVO4 photocatalyst varied between 2.25 and 2.32 eV. The as-synthesized BiVO4 photocatalyst was used to study the photocatalytic degradation of crystal violet (CV) dye under visible light illumination. The photocatalytic degradation experiment showed that the degradation percentage of crystal violet dye using BiVO4 reached 98.21% after 120 min. Mineralization of crystal violet dye was studied using a chemical oxygen demand analysis.

Investigation of photocatalytic degradation of crystal violet and its correlation with bandgap in ZnO and ZnO/GO nanohybrid

The photocatalytic efficiency of semiconducting catalytic material is greatly influenced by one of the important factor like band gap. In the area of sustainable energy and environmental decontamination, ZnO photocatalysts have been extensively used. However, there is a significant decrease in the photocatalytic performance of ZnO due its large band gap, and fast recombination of charge carriers. Various methods have been designed to address this issue, such as nanostructuring, chemical doping, introducing oxygen defects, surface sensitization, and employing nanocomposites. Here, the semiconducting ZnO, ZnO/GO were prepared by simple co-precipitation method and solid state reaction respectively. The synthesised ZnO, ZnO/GO catalysts were characterized thoroughly by different techniques such as X-ray diffraction (XRD), Raman spectroscopy, Fourier Transform infrared Spectroscopy (FTIR), Field emission scanning electron microscopy (FESEM), Diffuse reflectance spectroscopy(DRS), photoluminescence (PL), BET specific surface area. The Eg values of ZnO/GO has found to be 2.71 eV which is lower than the bare ZnO (2.81 eV), which is benefit to have higher photocatalytic activity. The performance of synthesized catalysts was explored for remediation of CV dye by employing visible light as energy source to begin photoreaction. The ZnO/GO nanohybrid has shown 99% degradation of CV in 240 min under neutral pH and rate constant found to be 0.01514 min−1 which is much higher than bare ZnO. In ZnO/GO nanohybrid, the phenomenal photocatalytic efficacy was attributed to the suppressed charge carriers (electron in CB and holes in VB) recombination and adequate injection of photosensitized electron in the hybrid during the photocatalytic reaction. Further, GO itself acts as electron collector and transporter and thereby furnishes electrons for enhancing the photocatalytic reaction by providing reactive oxygen species and hydroxyl radicals for the degradation of crystal violet. Addtionally, the interrelationship between the physical properties like band gap and catalytic competence were founded.