Crystal Violet Dye Research Articles

Nanostructured codoped neodymium orthoferrite synthesized via the hydrothermal route for photocatalytic annihilation of crystal violet dye

Current research demonstrates the synergistic effects of gadolinium (Gd)/copper (Cu) codoping and nanotechnology on various physicochemical and photocatalytic features of neodymium iron oxide (NIO) perovskites. X-ray diffraction (XRD) and Fourier transform infrared (FTIR) studies the synthesis of pure neodymium oxide (NIO-I) and its codoped counterpart (NIO-II) with a perovskite-type crystal structure via simple hydrothermal techniques. Through codoping and nanostructural synthesis, the surface characteristics, as well as the optical, electrical, and optoelectronic properties of the neodymium iron oxide perovskite, were enhanced, as confirmed by Brunner−Emmett−Teller (BET), UV/Vis, current−voltage (I−V), and photoluminescence (PL) studies. In terms of photocatalytic activity, the NIO-II perovskite outperforms its undoped NIO-I counterpart, eliminating 91.8 % of crystal violet (CV) dye in less than 50 min with a rate constant value (k) of 0.019 min−1. However, the undoped counterpart removed 63.8 % of the CV dye, with a comparatively lower rate constant of 0.013 min−1 under the same conditions. Under alkaline conditions, the NIO-II catalyst demonstrates superior efficiency in degrading CV dye; moreover, it maintains an efficiency of 96.8 %, even after undergoing five cycles of reuse. Through the use of rare earth and transition metal codoping, this study reveals a new way to fine-tune the structural and other pertinent properties of semiconductor perovskites, ensuring their practical use for the treatment of polluted water.

Optimum and Green Fabrication of MIL-100(Fe) for Crystal Violet Dye Removal from Aqueous Solution

MIL-100(Fe) was prepared and subsequently used to remove crystal violet dye from aqueous solutions simulating dye-containing wastewater in the environment. In the future, it is aimed that MIL-100(Fe) can be used in managing dye-containing wastewater in the environment and reducing the negative impacts it can cause. Here, MIL-100(Fe) fabrication needs to be optimized to obtain optimum process conditions, which are environmentally friendly and can produce MIL-100(Fe) with the best characteristics. This study focused on optimizing the fabrication of MIL-100(Fe), which is a type of MOF with good chemical stability, thermal stability, and flexible structure. In this study, the room-temperature fabrication of MIL-100(Fe) was established using a ligand-to-metal molar ratio of 0.95 and an acetic acid concentration of 5.1 vol% for 6.2 h. The optimum MIL-100(Fe) was tested for crystal violet removal and provided an optimum removal capacity of 182.66 ± 3.81 mg/g. Statistical approaches are used to investigate the independent parameters and their interactions contributing to MIL-100(Fe) formation.

Novel magnetic metal ferrite-mango starch composite for the removal of dyes in single and ternary dye mixtures from aqueous solutions: kinetic and thermodynamic studies

ABSTRACT Magnetic metal ferrites attached to biowastes are proven to be promising adsorbents for the removal of dyes from water. Magnetic composites with biopolymers are gaining interest in the field of treatment of wastewater because of their selective nature, recyclability, low cost and environmental compatibility. In this work, Zinc ferrite composite with starch, extracted from mango seed kernel (ZFNMS) was synthesised. Characterisation techniques, such as FTIR, XRD, FESEM, BET, TGA and pHzpc, were used for the structural analysis of ZFNMS. ZFNMS was used to remove Methylene blue, Crystal violet and Brilliant green dyes in single and multiple (ternary) dye systems. The kinetics of adsorption by ZFNMS revealed that pseudo-second-order of kinetics was most appropriate for this study. Maximum adsorption capacities using ZFNMS for CV, BG and MB dyes were 142.9, 101.2 and 105.8 mg/g, respectively. The values of adsorption energies using ZFNMS were 200.5, 494.3 and 183.6 KJ/mol for CV, BG and MB dyes, respectively. Thermodynamic data revealed the spontaneous nature of the adsorption of dyes by ZFNMS and it was found that chemical adsorption was taking place in the present study. Regeneration of the adsorbent was done for successive five cycles and showed significant results. Thus ZFNMS is an ideal adsorbent for cationic dyes removal from water.

Synthesis of novel composite material with spent coffee ground biochar and steel slag zeolite for enhanced dye and phosphate removal.

Rising concerns over water scarcity, driven by industrialization and urbanization, necessitate the need for innovative solutions for wastewater treatment. This study focuses on developing an eco-friendly and cost-effective biochar-zeolite composite (BZC) adsorbent using waste materials-spent coffee ground biochar (CGB) and steel slag zeolite (SSZ). Initially, the biochar was prepared from spent coffee ground, and zeolite was prepared from steel slag; their co-pyrolysis resulted in novel adsorbent material. Later, the physicochemical characteristics of the BZC were examined, which showed irregular structure and well-defined pores. Dye removal studies were conducted, which indicate that BZC adsorption reach equilibrium in 2h, exhibiting 95% removal efficiency compared to biochar (43.33%) and zeolite (74.58%). Moreover, the removal efficiencies of the novel BZC composite toward dyes methyl orange (MO) and crystal violet (CV) were found to be 97% and 99.53%, respectively. The kinetic studies performed with the dyes and phosphate with an adsorbent dosage of 0.5g L-1 suggest a pseudo-second-order model. Additionally, the reusability study of BZC proves to be effective through multiple adsorption and regeneration cycles. Initially, the phosphate removal remains high but eventually decreases from 92% to 70% in the third regeneration cycle, highlighting the robustness of the BZC. In conclusion, this study introduces a promising, cost-effective novel BZC adsorbent derived from waste materials as a sustainable solution for wastewater treatment. Emphasizing efficiency, reusability, and potential contributions to environmentally conscious water treatment, the findings highlight the composite's significance in addressing key challenges for the removal of toxic pollutants from the aqueous solutions. PRACTITIONER POINTS: A novel biochar-zeolite composite (BZC) material has been synthesized. Excellent removal of dyes by BZC (~95%) was achieved as compared to their counterparts The kinetic studies performed suggest a pseudo-second-order model. BZC proves to be highly effective for multiple adsorption studies. Excellent reusability showed potential as a robust adsorbent.

Green synthesis of Z-scheme CeO2 decorated ZnO nanocomposites for photodegradation of organic pollutants, antioxidant activity and its effects on seed germination

The present work aimed to report a green synthesis of CeO2@ZnO nanocomposites via co-precipitation method using azadirachta indica aqueous leaf extract. The characterization of the prepared CeO2@ZnO nanocomposites were done using XRD, FTIR, SEM, EDAX, UV–vis, and PL techniques to examine the structural properties, functional group, morphological and electronic properties. As prepared CeO2@ZnO nanocomposites have been used for photo degradation of Crystal Violet (CV), Methylene blue (MB) and Rhodamine B (RhB) dyes in presence of solar light in aqueous solution. From structural analysis the mean crystallite sizes of the synthesized nanocomposites varied from 27 nm to 9 nm. The degradation of MB, CV and RhB dyes follows pseudo-first order reaction rate with the rate constantsk1 for MB is 10.09 × 10−3 min−1, k1 for CV is 8.71 × 10−3 min−1, k1 for RhB is 0.92 × 10−3 min−1.The characterized nanocomposites were used for seedling growth, physiological and biochemical responses during seed germination. In CeO2@ZnO nanocomposites treatments, significantly higher values of shoot length and root length were observed in CZ1 (0.5, and 1 mg/ml) treated seedlings as compared to other samples. Similarly, the activities of ɑ-amylase and protease enzymes were recorded to be maximum for CZ1 nanocomposites. For instance, the increased activity of α-amylase was observed to be 2.12, 2.09, and 1.33 folds higher in CZ1, CZ2, and CZ3 (1 mg/ml) treated seedlings as compared to the control. Similarly, the protease activity was reported to be increased by 0.011 folds in CZ1 nanocomposites (1 mg/ml) treated seedlings as compared to the control. Furthermore, all the CeO2@ZnOnanocomposites have excellent DPPH, and ABTS free radical scavenging activities, confirmed by the Ferric-Reducing Antioxidant Power (FRAP) assay. The CZ1 nanocomposites showed the best results. The CeO2@ZnO nanocomposites were found to have no toxic effects on cellular division confirmed with improved mitotic index under different treatment regimens.

Assembly of Fe@Zn-Coordination Polymer Composite: Iron Doping Foster the Luminescent Detection for Tetracycline, Uric Acid and Cr2O72− and Crystal Violet Degradation Efficiency

Coordination polymers exhibit a diverse array of applications across various fields, and through the development of composite materials, their utility and versatility are further enhanced, broadening their impact on our world. In this work We synthesized the first coordination polymer (CP) based on Zn and doped with Fe composites (Fe@Zn-CP Composite), which exhibit enhanced photocatalytic activity triggered by visible light. Using mixed ligands orotic acid potassium salt, 1,3 di (4-pyridyl) propane (dpp), and FeSO4 in a simple method at ambient temperature, the Zn-CP [Zn8(Or)8(dpp)4(H2O)8] was resynthesized here to form the Fe@Zn-CP composites. Zn-CP and Fe@Zn-CP Composite were both characterized by powder X-ray diffraction, FT-IR spectra analysis, and SEM-EDX analysis and elemental mapping analysis. It has been observed that Fe@Zn-CP Composite is as multi-functional luminescence sensor for MnO4−, Cr2O72− and Tetracycline with high sensitivity. In-depth research has also been done on the recyclable nature, and photocatalytic efficiency of Zn-CP and Fe@Zn-CP Composite for the decomposition of organic dyes Crystal Violet and Rose Bengal (RB) in contaminated water under the sunlight irradiation.

Solvothermal synthesis, photoelectricity and photocatalysis of biselenide-containing selenidostannate hybrid with one-dimensional structure

A biselenide-containing selenidostannate hybrid with narrow band gap, [Ni(terpy)2]2[Sn3Se7][Sn3Se6(Se2)]·4H2O (1) (terpy = 2,2′:6′,2′’-terpyridine), was prepared using a Ni(II)-terpy complex cation as the template under solvothermal conditions. In 1, two SnSe5 PBUs and one SnSe4 PBU are joined through edge-sharing to form a Sn3Se9 SBU. The Sn3Se9 SBUs are connected into a 1-D [Sn3Se7]n2n− chain by sharing two Se atoms, while the Sn3Se7(Se2)2 SBUs are interlinked via the same conncetion mode to form a [Sn3Se6(Se2)]n2n− polyselenide chains containing biselenide ligands. Compound 1 exhibited sensitive photocurrent responses under Xe light irradiation, and had a steady current density of 6.88 μA·cm−2 under visible light irradiation at power of 150 W. Compound was photocatalytically active in the degradation of the organic dye crystal violet (CV) in aqueous solution at room temperature, and the degradation ratio of CV reached 93.8 % after 60 min of light irradiation. Radical quenching experiments showed that all the ∙O2− and ·OH radicals, and the photogenerated positive holes h+ were involved in the photodegradation of CV.

Green synthesis of NiO and NiO@graphene oxide nanomaterials using Elettaria cardamomum leaves: Structural and electrochemical studies

An eco-friendly synthetic route was developed for the formation of nickel oxide (NiOaq and NiOet) nanoparticles (NPs) by treating Ni(NO3)2.6H2O with aqueous/ethanolic extracts of Elettaria cardamomum leaves; the same reaction was performed in the presence of graphene oxide (GO) to produce NiOaq@GO and NiOet@GO nanocomposites (NCs), respectively. The NMs were characterized by XRD, FT-IR, SEM, EDX, UV–visible spectroscopy, and TGA-DSC analysis. They were also subjected to electrochemical investigations and photocatalytic degradation of crystal violet (CV) dye. XRD analysis revealed the average crystallite sizes of 8.84–14.07 nm with a face-centered cubic form of NiO NPs and a hexagonal structure of their nanocomposites with GO. FT-IR spectroscopy confirmed the presence of Ni-O vibrations at 443-436 cm−1. SEM images confirmed the spherical morphology of NiO NPs while NiOaq@GO NCs contained randomly aggregated, thin, and wrinkled graphene sheets. NiOaq and NiOet have shown particle sizes of 27.7–30.63 nm which were decreased to 19.33–26.39 nm in their respective NiOaq@GO and NiOet@GO NCs. EDX spectra verified the homogeneous distribution of elements (Ni, O, C) on the surface of the particles. The synthesized NCs have shown smaller band gaps (NiOaq@GO = 3.74 eV; NiOet@GO = 3.34 eV) as compared to their respective NPs (NiOaq = 5.0 eV; NiOet = 3.89 eV). TGA/DSC data was used to find the thermal stabilities, glass transition temperatures, and enthalpies. Cyclic voltammetry measurements exhibited distinct oxidation and reduction peaks. NCs exhibited better potential as electrode materials for supercapacitor applications as compared to their respective NPs. NiOet@GO exhibited the best electrochemical performance and photocatalytic degradation efficiency of CV dye. After 120 min exposure to sunlight, the degradation coefficient of CV was observed to be 82.93, 86.34, 89.99, 90.27 and 81.65 % in the presence of NiOaq, NiOet, NiOaq@GO, NiOet@GO and GO, respectively.

Biosynthesis of the Ag Doped SnO2 Nanorods Supported Bentonite Clay with Enhanced Photocatalytic Activity Against Crystal Violet Dye

Biosynthesis of the Ag Doped SnO2 Nanorods Supported Bentonite Clay with Enhanced Photocatalytic Activity Against Crystal Violet Dye

Brazilian bentonite/MgO composites for adsorption of cationic and anionic dyes.

Industrial effluents, especially those containing dyes, have become the main cause of contamination of water resources. In this context, Brazilian bentonite/MgO composites, with excellent adsorptive properties, were prepared and investigated for their effectiveness in removing cationic and anionic dyes from aqueous solutions. The new adsorbents were obtained using Brazilian bentonites and MgO using the mechanochemical method followed by heat treatment (at 700°C for 4h). Different characterization techniques were used for the chemical, mineralogical, thermal, surface, and morphological analysis of the raw clays and the composites. The experimental adsorption isotherms were quantified under different conditions of initial concentration, contact time, pH, adsorbent dosage, and temperature variation to interpret the adsorption mechanism of the crystal violet (CV) and Congo red (CR) dyes. The modeling results were obtained from the empirical Sips equation and Pseudo Second Order (PSO) kinetics, indicating that the adsorption of molecules is a heterogeneous phenomenon that occurs in a monolayer on the surface (ns > 1), with the adsorption rate determined by chemisorption. The composites showed the best removal efficiency performance compared to the raw bentonites, with an increase of 12% for the CV dye and 46% for the CR dye. In addition, the qmax values obtained were 423.02mg/g and 479.86mg/g (AM01). This research underscores the potential of Brazilian bentonite/MgO composites as a promising solution for the removal of cationic and anionic dyes from water, offering hope for future applications in the field of environmental engineering and materials science.

Surface charge alteration of charcoal derived from bamboo leaves and understanding the interaction with anionic and cationic dye

Cost-effective adsorbents derived from regenerative sources provide a sustainable solution to the pressing environmental pollution challenges. Conventional studies often rely on biochar-based adsorbents obtained at high carbonization temperatures in an induced environment. The present study explored the efficacy of carbon derived from the stems (CBS) and leaves (CBL) of bamboo plants as efficient dye adsorbents at low carbonization temperatures. CBL carbonized at 350 °C exhibited a remarkable dye adsorption efficiency of 90%, significantly outperforming CBS, which achieved only 39% efficiency. To enable the adsorption of both dyes, heterophase metal oxides, specifically Fe-doped ZnO and ZnFe2O4 were incorporated. Zeta potential measurements revealed a transition from negative to positive values with metal oxide incorporation, suggesting alterations in the surface acidity and functional group composition. The adsorption performance of the composite (WC20) sample was evaluated using Congo Red (CR) and Crystal Violet (CV) dyes. Comprehensive studies on the adsorption kinetics, isotherm modeling, and thermodynamics have been conducted to identify WC20 as the most effective composite. The equilibrium adsorption data aligned well with the Langmuir isotherm model, demonstrating maximum adsorption capacities of 65.31 mg g−1 for CR and 38.05 mg g−1 for CV at room temperature of 298 K with constant pH. Thermodynamic analysis indicated a hybrid adsorption mechanism, wherein CR adsorption was predominantly driven by chemisorption, whereas CV adsorption was governed by physisorption. Mechanistic insights have revealed that electrostatic interactions and π–π stacking play crucial roles in dye removal. These findings underscore the potential applicability of WC20 as a cost-effective and efficient adsorbent for the remediation of both cationic (CV) and anionic (CR) dyes in wastewater, highlighting its viability for future environmental management and pollution mitigation strategies.

Synthesis and characterizations of a novel hydrogel for adsorptive removal of crystal violet dye from wastewater

Herein, a novel hydrogel (HG-cl-poly(AA)) was synthesized by grafting acrylic acid (AA) onto Hing gum (HG) using methylene-bis-acrylamide (MBA) as a cross-linker and ammonium persulfate (APS) as an initiator in a hot air oven. The percentage swelling of the hydrogel was examined by optimizing various reaction parameters to ensure its maximum swelling percentage. The formation of crosslinked networks was confirmed using Fourier-Transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), and thermogravimetric analysis (TGA) techniques. The surface area and hydrophilicity of the prepared hydrogel were determined using Brunauer–Emmett–Teller analyzer and wettability studies, demonstrating a clear correlation with adsorption. The adsorption of crystal violet (CV) dye on the prepared hydrogel was studied via a batch adsorption system based on the amount of adsorbent, immersion time, pH level, and initial dye concentration. The prepared hydrogel showed a 99% removal rate and an excellent adsorption capacity of 492.61[Formula: see text]mg/g due to the electrostatic, H-bonding, and dipole–dipole interactions between the adsorbent surface and dye molecules. The results were further analyzed using the Langmuir, Freundlich, and Tempkin isotherm models. The study suggests consistency with the pseudo-second-order kinetic model ([Formula: see text]), further supported by the best data fit with the Langmuir isotherm model ([Formula: see text]). The thermodynamic study results indicated that the adsorption process is endothermic and spontaneous. Regeneration (desorption) studies showed that the prepared hydrogel could remove CV dye from an aqueous solution and maintain the highest adsorption capacity even after multiple adsorption and desorption cycles. Therefore, the prepared HG-cl-poly(AA) hydrogel could be a potential adsorbent for dye removal and have an admirable capacity for cleaning the aquatic environment.

Adsorption ability of sugar scum as industrial waste for crystal violet elimination: Experimental and advanced statistical physics modeling

Recycling solid industrial waste into useful resources is the most critical aspect of managing waste. Herein, for detoxifying poisonous crystal violet dye (CV) in aqueous media, sugar scum (SS) as an underutilized industrial discard has been tested as a promising adsorbent.The SS was thoroughly analyzed beforehand and after the adsorption process through various characterization techniques. Several operational factors, including pH, biosorbent dosage, dye concentration, and temperature, were optimized, reaching 24 mg.g-1 at (pH 10, 2 g.L−1 of SS, 10 mg.L−1 of CV and 25 °C). The bioadsorbent's performance was assessed through a range of studies involving kinetic, equilibrium (using both conventional and statistical physics models), and thermodynamic investigations.Based on the results, the equilibrium curves best fit the Freundlich model, indicating that multilayer adsorption occurs on a heterogeneous active sites surface. The statistical physics models provided detailed physiochemical insights, the double-layer with two energies model was most accurately describing the data, with a high saturation capability of 371 mg.g−1. Most interactions occur at a single adsorption site (70 %), with the remaining 30 % at two sites, involving both parallel and non-parallel orientations. The mesoporous structure of the SS surface provides an optimum size for CV adsorption. Pore filling, Van der Waals forces, hydrogen bonding, π-π and electrostatic interactions are proposed as the possible mechanisms in the CV-SS system. Thermodynamic measurements indicate that CV adsorption is spontaneous (ΔG° < 0) and exothermic ΔH° (− 41.390 kJ mol−1).The SS recyclability was assessed, exhibiting encouraging sustainability with a slight fall in effectiveness (∼7 %) after 5 sequential usages. Altogether, this study makes a substantial contribution to the promotion of ecological water treatment strategies, which highlights the utility of using SS as an environmental alternative to water contaminant remediation.

Electrochemical removal of crystal violet dye from simulated wastewater by stainless steel rotating cylinder anode: COD reduction and decolorization

Crystal violet dye is a harmful organic pollutant when it exists in wastewater. It may potentially cause renal failure and respiratory issues in humans, while it is considered carcinogenic and mutagenic in aqua life. In this study, crystal violet dye was electrochemically removed from simulated wastewater using a stainless-steel rotating cylinder anode. Effects of anode rotation rate (250–500 rpm), applied current (400–750 mA), concentration of supporting electrolyte (0.3–0.6 M), and time (30–70 min) on chemical oxygen demand (COD) reduction and colour removal were studied. The experimental results were correlated by two quadratic regression models: one for COD reduction with R2 equals to 0.859, and one for colour removal with R2 equals to 0.934. Process optimization was conducted using the response surface methodology (RSM) with a rotatable central composite design CCD. The results showed that the optimum conditions for maximum COD reduction (86.89 %) and maximum colour removal (88 %) are as follows: anode rotation rate = 625 rpm, applied current = 658.568 mA, supporting electrolyte = 0.422 M and treatment time = 90 min. Generally, all the studied factors have a potential effect on the process efficiency.

Facile synthesis of rGO/ZnCo2O4 nanocomposite for enhanced photocatalytic dye degradation of crystal violet dye solution

The rGO/ZnCo2O4 nanocomposite (NCs) was synthesized using a hydrothermal method. The crystallite size, morphology, and optical properties of rGO, ZnCo2O4, and the rGO/ZnCo2O4 nanocomposite were extensively characterized using TG/DTA, FT-IR, UV-DRS, XRD, SEM with EDAX, and TEM techniques. The synthesized rGO/ZnCo2O4 NCs were crystalline with a cubic spinel structure and an average crystallite size of 19 nm, as confirmed by XRD. The optical bandgaps of pure ZnCo2O4 and the rGO/ZnCo2O4 nanocomposite were estimated to be 2.3 eV and 1.8 eV, respectively. The crystal violet (CV) dye was efficiently removed from an aqueous solution by photocatalytic degradation under visible light and sunlight irradiation in the presence of pure ZnCo2O4 and the rGO/ZnCo2O4 nanocomposite. The degradation results revealed that nearly 99.9 % of dye degradation was achieved with the rGO/ZnCo2O4 nanocomposite compared to pure ZnCo2O4 nanoparticles in 60 minutes. Hence, the rGO/ZnCo2O4 nanocomposite can be considered a promising and efficient photocatalyst for the degradation of crystal violet dye. The key highlight of this work is the low-cost, disruptive engineering strategy for synthesizing nanocatalysts for multifaceted applications.

Antifouling ultrafiltration membranes based on acrylic fibers waste/nanochitosan for Congo red and crystal violet removal

AbstractIn this study, acrylic fibers waste blended with different ratios of nanochitosan (0.5%, 1%, 2% and 4%, in weight) were converted into antifouling ultrafiltration nanocomposite membranes using a phase separation technique for the remediation of Congo red (CR) and crystal violet (CV) dyes from water. The fabricated nanocomposite membranes were investigated using Fourier Transform Infrared (FTIR), thermal gravimetric analysis (TGA), X-ray diffraction (XRD) and scanning electron microscope (SEM). The membrane hydrophilicity was estimated using contact angle measurements, which revealed that the 4% loaded nanochitosan had the highest hydrophilicity. Additionally, the water uptake, porosity, water contact angle and water flux of the nanocomposite membranes were assessed. The membrane filtration performances were explored for the removal of CR and CV as anionic and cationic dyes, respectively, at different concentrations and various applied pressures (1 bar to 4 bar). The experimental data revealed a high rejection (R) performance for CR (R≃100%) with a high water flux of about 150 L/(m2·h) to 183 L/(m2·h) for the optimized membrane with 2% nanochitosan at an applied pressure of 4 bar. The rejection for CV showed a variant rejection (70%–99%) at different dye concentrations with fluxes ranging from 93.6 L/(m2·h) to 149.5 L/(m2·h) for the same composite membrane. The composite membrane showed enhanced flux recovery after fouling by bovine serum albumin and was resistant to widespread gram-positive (Staphylococcus aureus) bacteria. Graphical abstract

Simplified synthesis and identification of novel nanostructures consisting of cobalt borate and cobalt oxide for crystal violet dye removal from aquatic environments

Crystal violet dye poses significant health risks to humans, including carcinogenic and mutagenic effects, as well as environmental hazards due to its persistence and toxicity in aquatic ecosystems. This study focuses on the efficient removal of crystal violet dye from aqueous media using novel Co3O4/Co3(BO3)2 nanostructures synthesized via the Pechini sol–gel approach. The nanostructures, which were abbreviated to EN600 and EN800, were fabricated at calcination temperatures of 600 and 800 °C, respectively. X-ray diffraction (XRD) analysis revealed that the synthesized samples have a cubic Co3O4 phase and an orthorhombic Co3(BO3)2 phase, with mean crystal sizes of 43.82 nm and 52.93 nm for EN600 and EN800 samples, respectively. The Brunauer–Emmett–Teller (BET) surface areas of EN600 and EN800 samples were 65.80 and 43.76 m2/g, respectively, indicating a significant surface area available for adsorption. Optimal removal of crystal violet dye was achieved at a temperature of 298 K, a contact time of 70 min, and a pH of 10. The maximum adsorption capacities were found to be 284.09 mg/g for EN600 and 256.41 mg/g for EN800, which are notably higher compared to many conventional adsorbents. The adsorption process followed the pseudo-second-order kinetic model and fitted well with the Langmuir isotherm. The adsorption was exothermic, spontaneous, and physical in nature. Moreover, the adsorbents exhibited excellent reusability, retaining high efficiency after multiple regeneration cycles using 6 mol/L hydrochloric acid. These findings highlight the potential of these Co3O4/Co3(BO3)2 nanostructures as effective and sustainable materials for water purification applications.

Conversion of invasive plant species (Bidens pilosa L.) into bioadsorbents for simultaneous removal of ciprofloxacin antibiotic and crystal violet dye

Conversion of invasive plant species (Bidens pilosa L.) into bioadsorbents for simultaneous removal of ciprofloxacin antibiotic and crystal violet dye

Design of a phosphate-based glass system as adsorbent for crystal violet dye removal

This study introduces the utilization of a novel approach using glass-based systems as standalone adsorbents for extracting crystal violet (CV) dye from aqueous solutions. A phosphate-based glass 60NaPO3-10TiO2-30V2O5 was synthesized using the conventional melt quenching technique. Characterization was conducted using a variety of analytical techniques including Fourier transform infrared spectroscopy (FTIR), X-ray energy dispersive spectroscopy (EDS), scanning electron microscopy (SEM), Brunauer-Emmett-Teller (BET), Raman spectra, Thermal Gravimetric Analysis (TGA) and X-ray analysis (XRD). The glass exhibited effective adsorption capacity for CV dye, marking the first-time use of phosphate-based glass as an adsorbent. The findings suggested that the adsorption process was impacted by different physicochemical parameters. The Freundlich isotherm and pseudo-first-order models demonstrated a strong fit in isothermal and kinetic adsorption modeling, respectively. The utmost adsorption capacity observed was 262.74 mg g−1. Thermodynamic analysis suggested that the process of adsorption of CV dye was spontaneous and exothermic. These findings indicate that the synthesized phosphate-based glass has a high potential for wastewater treatment containing CV dye.

Green synthesis of Zn-doped TiO2 nanomaterials for photocatalytic degradation of crystal violet and methylene blue dyes under sunlight

Green synthesis of Zn-doped TiO2 nanomaterials for photocatalytic degradation of crystal violet and methylene blue dyes under sunlight