Efficient Dye Adsorption Research Articles

Electrospun nanofiber chitosan/polyvinyl alcohol loaded with metal organic framework nanofiber for efficient adsorption and removal of industrial dyes from waste water: Adsorption isotherm, kinetic, thermodynamic, and optimization via Box-Behnken design.

Dyes can seriously harm human health because they linger or break down in the environment and find their way into drinking water through the water cycle. Examples of the most important interactions between MOFs and dyes are provided, and an effort is made to comprehend how surface charge and size compatibility affect the adsorption process. The methods for incorporating functionalized Ce-MOF into electrospun nanofibers made of polyvinyl alcohol and chitosan to create functionalized cerium metal organic framework nanofiber membranes (FCCP nanofiber membranes) are presented in this paper. A number of techniques, including XRD, FT-IR, N2 adsorption/desorption isotherm, SEM mapping, and EDX, were used to successfully manufacture and analyze the adsorbent. Examine the effects of pH, adsorbent dose, starting concentration, contact time, and thermodynamics on the adsorption process of malachite green dye (MG) onto FCCP nanofiber membrane. The Langmuir and pseudo-second-order adsorption processes were fitted. The adsorption process was chemisorption, as shown by the adsorption energy of 31.6kJ/mol. Examine the adsorption mechanism, which may involve electrostatic interaction, pore filling, and π-π interaction. The increase in MG dye absorption at higher temperatures suggests an endothermic and spontaneous adsorption process. For the MG dye solution, the ideal adsorption parameters were determined using the Box-Behnken design software to be pH8, a dosage of 0.2g of FCCP nanofiber membrane per 25mL, and an adsorption capacity of 359.2mg/g. These elements are necessary for the composite sponge to be utilized in water purification processes and to be the most successful at adsorbing arsenate. Applying the Box-Behnken design and response surface approach features of the Design-Expert software successfully enhanced the adsorption process with a small number of planned tests. The stability of the adsorbent was confirmed by an investigation of its reusability using six consecutive cycles of adsorption and desorption, which revealed no appreciable drop in removal effectiveness. It also demonstrated consistent efficiency, preserved homogeneous XRD data, and kept its original chemical composition both before and after reuse.

Facile vacuum annealing of thiourea-induced synthesis of graphitic carbon nitride for the efficient adsorption of anionic dyes

Facile vacuum annealing of thiourea-induced synthesis of graphitic carbon nitride for the efficient adsorption of anionic dyes

Closed-loop recylcing of thermoset poly(vinylogous urethane) foams

Foams are an intriguing class of porous and lightweight materials which have found widespread applications in thermal insulation, pollutant adsorption, catalyst support, and energy storage. However, their covalently cross-linked structure makes foam unable to be recycled resulting in serious environmental burden. To address this challenge, we report the first example of closed-loop chemically recyclable foam. A simple, catalyst-free cryo-polymerization process with multifunctional amines and acetoacetates was utilized to successfully prepare a series of poly(vinylogous urethane) foams, containing dynamic covalent bonds which can selectively be cleaved on demand. The resulting foams exhibit macroporous structure with diameters exceeding 14 μm, pronounced thermal stability (Td,5% > 262.5 °C), robust hydrophobicity (WCA > 93°) and unique reactivity. Applications have been demonstrated for efficient adsorption of organic solvents and anionic dyes. More importantly, the foams show excellent recyclability under acidic conditions with high monomer recovery yields of up to 97 % and high purity levels. Fresh foams could be regenerated from the retrieved building blocks, thus demonstrating efficient closed-loop recycling. This work provides a new “monomer-foam-monomer” ecological chain and may inspire the advancement of next-generation closed-looped recyclable foam materials.

Highly efficient iodine capture and selective adsorption and removal of cationic dyes by using a copper-based coordination polymer decorated over graphene oxide and carbon nanotubes

This study focuses on synthesizing hybrid nanocomposites (HNCs) through a one-step solvothermal method, combining highly crystalline and evenly dispersed copper-based coordination polymer (Cu-CP), graphene oxide (GO), and carbon nanotubes (CNTs). Extensive characterization using elemental analysis, SEM, TEM, EDX, XRD, FT-IR, Raman spectroscopy, TGA, and crystallographic studies confirm the properties of the nanocomposites, with PXRD investigation supporting their clear crystalline structure. Morphological and elemental studies reveal effective adsorption of copper-benzoic acid-containing Cu-CP onto GO and CNT substrates. The synthesized nanocomposites exhibit superior adsorption capacity for iodine (I2), a model radioactive pollutant, attributed to decreased CP size and larger surface area. The strong affinity for I2 arises from various interactions, including conjugated π-electron aromatic systems and halogen bonds. Cu-CP, Cu-CP@GO, and Cu-CP@CNT adsorbents efficiently extract toxic iodine from hexane solution, achieving a substantial capture capacity of 347.85 mg/g over 24 h. In the vapor phase, Cu-CP@GO exhibits an even higher capacity (951.52 mg/g within 25 h). Moreover, the application of Cu-CP, Cu-CP@GO, and Cu-CP@CNT in environmental protection showcases their efficacy in removing cationic and anionic dyes, particularly highlighting remarkable cationic dye selectivity through cation-π and π-π interactions. This research underscores the promising potential of these HNCs in addressing environmental challenges and pollutant remediation.

N-doped three-dimensional carbon nanosheets: Facile synthesis and high-concentration dye adsorption

Purification of dye-contaminated wastewater has always been a research hotspot, yet also a challenge, due to high concentration and species diversity of pollutants. The present study designs an efficient nitrogen-doped 3D carbon nanosheets (N-3DCNs) adsorbent with 2592.50 m2 g−1 of specific surface area and 2.68 m3/g of average pore volume based on nitrilotriacetic acid trisodium salt by combining calcination and activation techniques. Microstructure and surface potential of N-3DCNs indicate that a large number of N heteroatoms in the lattice of main material can effectively optimize Zeta potential from 1.53 to −31.08 mV with solution pH increases from 3 to 11. So, as-prepared N-3DCNs possesses necessary conditions for efficient and selective adsorption of cationic dyes due to the abundant adsorption sites and strong electrostatic interactions. When 700 mg/L of cationic rhodamine and anionic methyl orange are respectively used as high concentration industrial dye-contaminated wastewater, N-3DCNs shows 97.97 % and 89.13 % of removal efficiency within 60 min. Furthermore, the adsorption capacity of N-3DCNs displays a wider pH tolerance at 1000 mg/L of cationic concentration, with a maximum adsorption capacity of 4888.70 mg/g at pH = 7 and a minimum value of 4203.77 mg/g at pH = 3, only 14 % of attenuation rate. The kinetics mechanism of dye adsorption could be well explained by pseudo-second-order kinetic model, suggesting chemisorption behavior, while fitting better with the linear Langmuir isothermal model. The groundbreaking and exceptional adsorption performances of N-3DCNs can be attributed primarily to the high specific surface area and negatively charged active sites, facilitating synergistic adsorption.

Interfacial and electronic dual regulation of metal organic frameworks for enhanced catalytic oxidation of peroxymonosulfate into dyes

In heterogeneous advanced oxidation processes, it is important to improve the catalytic performance, which can be achieved by increasing the mass transfer of catalysts and utilization efficiency of reactive oxygen species (ROSs). Herein, the functional groups, amino group (NH2) and hydroxyl group (OH), were introduced onto the surface of metal organic frameworks (MOFs), FeBDC (Iron terephthalate) by ligand exchange. The synthesized MOFs were used as catalysts to activate peroxymonosulfate (PMS) for the efficient removal of dye from wastewater. The NH2/-OH groups accumulated at the surface of MOFs to significantly enhanced their hydrophilicity, which favored dye adsorption efficiency on the surface of MOFs from aqueous solution. This dye enrichment was benefited to the high utilization of ROSs due to the shorter transfer distance in solution. Additionally, the introduction of NH2/OH favored the reduction in electrochemical resistance both within the bulk and at the interface of the MOFs, thereby facilitating the electron transfer from the MOFs to PMS. The efficient utilization of ROSs (the radicals (SO4− and O2−) and non-radical (1O2)) generated by PMS removed nearly all RB171 (96.2–98.5 %) by oxidation reaction. The azo bonds and aromatic rings of dye molecules were susceptible to the attack by these ROSs. At the utilization of 5 cycles, iron leaching from MOFs/PMS was very low, satisfying the value of discharge standards. This work demonstrates that the functional groups presented in MOFs effectively facilitate the dual regulation of dye enrichment and catalytic activity in heterogeneous advanced oxidation processes.

Block copolymer nanoparticles doping polyacrylonitrile membranes for efficient adsorption of water-soluble dyes from water

Polyacrylonitrile (PAN) membranes doped with cross-linked fluorinated block copolymer nanoparticles of poly[(poly(ethylene glycol) methacrylate)-b-poly(2,2,2-trifluoroethyl acrylate)-b-polystyrene] [P(PEGMA)-b-PTFEMA-b-PS] with high flux and high adsorption of water-soluble dyes were prepared by phase transition method. The preparation of the PAN membranes includes (1) preparation of P(PEGMA)-b-PTFEMA-b-PS nanoparticles containing the –OH terminal by polymerization induced self-assembly (PISA); (2) preparation of hydrolyzed PAN containing the –COOH moieties with about 1% hydrolysis degree to increase the adsorption of water-soluble dyes; (3) grafting hydrolyzed PAN onto the P(PEGMA)-b-PTFEMA-b-PS nanoparticles through esterification between the –OH terminal and –COOH; (4) formation of modified PAN membranes through phase transition method in the presence of the HPAN-grafting block copolymer nanoparticles. The flux and equilibrium absorption of the modified PAN membranes are 8 times higher and 143% higher than those of the unmodified PAN membranes, respectively. It suggests that modifying PAN membranes by doping with cross-linked fluorinated block copolymer nanoparticles may be a promising method to prepare high performance membranes.

MgAl-Layered Double Hydroxide-Coated Bio-Silica as an Adsorbent for Anionic Pollutants Removal: A Case Study of the Implementation of Sustainable Technologies.

The adsorption efficiency of Cr(VI) and anionic textile dyes onto MgAl-layered double hydroxides (LDHs) and MgAl-LDH coated on bio-silica (b-SiO2) nanoparticles (MgAl-LDH@SiO2) derived from waste rice husks was studied in this work. The material was characterized using field-emission scanning electron microscopy (FE-SEM/EDS), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), and X-ray photoelectron spectroscopic (XPS) techniques. The adsorption capacities of MgAl-LDH@SiO2 were increased by 12.2%, 11.7%, 10.6%, and 10.0% in the processes of Cr(VI), Acid Blue 225 (AB-225), Acid Violet 109 (AV-109), and Acid Green 40 (AG-40) dye removal versus MgAl-LDH. The obtained results indicated the contribution of b-SiO2 to the development of active surface functionalities of MgAl-LDH. A kinetic study indicated lower intraparticle diffusional transport resistance. Physisorption is the dominant mechanism for dye removal, while surface complexation dominates in the processes of Cr(VI) removal. The disposal of effluent water after five adsorption/desorption cycles was attained using enzymatic decolorization, photocatalytic degradation of the dyes, and chromate reduction, satisfying the prescribed national legislation. Under optimal conditions and using immobilized horseradish peroxidase (HRP), efficient decolorization of effluent solutions containing AB-225 and AV-109 dyes was achieved. Exhausted MgAl-LDH@SiO2 was processed by dissolution/precipitation of Mg and Al hydroxides, while residual silica was used as a reinforcing filler in polyester composites. The fire-proofing properties of composites with Mg and Al hydroxides were also improved, which provides a closed loop with zero waste generation. The development of wastewater treatment technologies and the production of potentially marketable composites led to the successful achievement of both low environmental impacts and circular economy implementation.

Pyrene‐Functionalized Silicon Hybrid Porous Polymer for an Efficient Adsorption of Dyes

Pyrene‐Functionalized Silicon Hybrid Porous Polymer for an Efficient Adsorption of Dyes

Organic micro/nanospheres assembled from a [2 + 2] Schiff base macrocycle for efficient adsorption of zinc ions and dyes

A Schiff base macrocycle (M) containing both isophthalamide and bissalicylaldehyde scaffolds was successfully designed and synthesized. M exhibited typical aggregation-induced enhanced emission characteristics in a mixed solvent of DMF/water, and showed high selectivity for the recognition of Zn(II) over other metal ions. The binding process, binding ratio, and association constant of M with Zn(II) were estimated through UV–vis and fluorescence spectra titrations, isothermal titration calorimetry, and 1H NMR titration experiments, and the detection limit towards Zn(II) was calculated as 1.03 × 10−7 mol·L−1. Interestingly, a large amount of micro/nanospheres of M with remarkable size uniformity were obtained from the reaction medium with sulfuric acid as a catalyst. On the basis of exploring the formation process of the micro/nanospheres and the key factors affecting their morphology and size, the Zn(II) and dye adsorption experiments were carried out. The results indicated that the micro/nanospheres of M can be applied to Zn(II) and dye adsorption with satisfactory removal rates.

Composite of Hydrolyzed PAN and β-Cyclodextrin Forms a Nanofiber Membrane with an Excellent Removal Effect on Various Cationic Dyes and Copper Ions.

The presence of dyes and heavy metals in wastewater represents a significant environmental and public health hazard, necessitating the development of efficient materials for their removal. In this study, we modified hydrolyzed polyacrylonitrile (PAN-H) and combined it with β-cyclodextrin (β-CD) by using an electrostatic spinning technique to fabricate composite nanofibrous membranes for water treatment applications. The resulting PAN-H/β-CD nanofiber membranes exhibit spindle-shaped fibers and porous structures with a high density of charged functional groups, which significantly enhance their selective adsorption capacity compared to pure PAN fibers. Furthermore, post-treatment with a sodium bicarbonate solution further improved this capacity, resulting in the membranes demonstrating a remarkable adsorption efficiency for cationic dyes. The adsorption process conformed to the Langmuir and pseudo-second-order kinetic models, with maximum adsorption capacities of 216.94 mg/g for methylene blue (MB), 471.59 mg/g for malachite green (MG), 299 mg/g for crystal violet (CV), and 43.95 mg/g for copper ions. The selective adsorption of these positively charged contaminants, particularly cationic dyes and metallic copper, indicates that PAN-H/β-CD membranes have significant potential for the treatment of wastewater containing similar pollutants.

Enhanced photocatalysis via inverse opal structures: Synthesis and characterization of TiO2/ZnO and ZnO/TiO2 composites using plasma-enhanced ALD

Inverse opals (IO) based functional materials show potential in photocatalysis due to their unique light interaction properties. This study presents a low-temperature plasma-enhanced atomic layer deposition (PEALD) method for synthesizing TiO2, ZnO, and composite IOs using a polystyrene nanoparticle-based opal template. We comprehensively characterized the obtained materials using SEM-EDX, TSEM, TG, FTIR, XRD, Raman, ellipsometry, photoluminescence (PL), and UV–Visible spectroscopy. SEM analysis confirmed the successful formation of PEALD IOs with a periodically ordered structure, enabling conformal coating while preserving their original architecture. XRD and Raman analysis also confirmed that the IOs consisted of anatase for TiO2 and hexagonal wurtzite for ZnO. UV–Vis reflectance spectroscopy revealed strong UV absorption and modified photonic bandgaps (PBGs) for all materials. The bare and composite IOs exhibited PBGs in the visible region, suggesting that the arising “slow photon” effect might enhance photocatalysis. This study explored the photocatalytic degradation of 4-Nitrophenol (4-NP) and Rhodamine 6G (Rh6G) using pristine and composite IO photocatalysts under UV and visible light irradiation. Pristine TiO2 and ZnO IOs demonstrated superior performance for 4-NP degradation under UV light. This can be attributed to two key factors: their highly ordered macroporous structure (with a large surface area for efficient dye adsorption, and their band gaps (3.0 eV for TiO2 and 3.2 eV for ZnO) that enable strong absorption of UV light photons for effective pollutant degradation. Conversely, composite IOs (TiO2/ZnO and ZnO/TiO2) displayed higher activity for both test molecules under visible light due to a synergistic effect between bandgap harmonization and the PBG effect.

Polymeric resins containing modified starch as environmentally friendly adsorbents for dyes and metal ions removal from wastewater.

Effective removal of organic and inorganic impurities by adsorption technique requires the preparation of new materials characterized by low production costs, significant sorption capacity, and reduced toxicity, derived from natural and renewable sources. To address these challenges, new adsorbents have been developed in the form of polymer microspheres based on ethylene glycol dimethacrylate (EGDMA) and vinyl acetate (VA) (EGDMA/VA) containing starch (St) modified with boric acid (B) and dodecyl-S-thiuronium dodecylthioacetate (DiTDTA) for the removal of dyes: C.I. Basic Blue 3 (BB3) and C.I. Acid Green 16 (AG16) and heavy metal ions (M(II)): Cu(II), Ni(II), and Zn(II) from water and wastewater. The adsorbents were characterized by ATR/FT-IR, DSC, SEM, BET, EDS, and pHPZC methods. These analyses demonstrated the successful modification of microspheres and the increased thermal resistance resulting from the addition of the modified starch. The point of zero charge for EGDMA/VA was 7.75, and this value decreased with the addition of modified starch (pHPZC = 6.62 for EGDMA/VA-St/B and pHPZC = 5.42 for EGDMA/VA-St/DiTDTA). The largest specific surface areas (SBET) were observed for the EGDMA/VA microspheres (207m2/g), and SBET value slightly decreases with the modified starch addition (184 and 169m2/g) as a consquence of the pores stopping by the big starch molecules. The total pore volumes (Vtot) were found to be in the range from 0.227 to 0.233cm3/g. These materials can be classified as mesoporous, with an average pore diameter (W) of approximately 55Å (5.35-6.10nm). The SEM and EDS analyses indicated that the EGDMA/VA microspheres are globular in shape with well-defined edges and contain 73.06% of carbon and 26.94% of oxygen. The microspheres containing modified starch exhibited a loss of smoothness with more irregular shape. The adsorption efficiency of dyes and heavy metal ions depends on the phases contact time, initial adsorbate concentration and the presence of competing electrolytes and surfactants. The equilibrium data were better fitted by the Freundlich isotherm model than by the Langmuir, Temkin, and Dubinin-Radushkevich models. The highest experimental adsorption capacities were observed for the BB3 dye which were equal to 193mg/g, 190mg/g, and 194mg/g for EGDMA/VA, EGDMA/VA-St/B, EGDMA/VA-St/DiTDTA, respectively. The dyes and heavy metal ions were removed very rapidly and the time required to reach system equilibrium was below 20min for M(II), 40min for BB3, and 120min for AG16. 50% v/v methanol and its mixture with 1M HCl and NaCl for dyes and 1M HCl for M(II) desorbed these impurities efficiently.

A screening guide for efficient dye adsorbents under continuous flow conditions: a review

A screening guide for efficient dye adsorbents under continuous flow conditions: a review

Sustainable Activated Carbon from Agricultural Waste: A Study on Adsorption Efficiency for Humic Acid and Methyl Orange Dyes

In this study, porous activated carbon was produced from coffee waste and used as an effective adsorbent for the removal of humic acid (HA) from seawater and methyl orange (MO) dye from aqueous solutions. Phosphoric acid H3PO4 was used as an activating agent for the chemical activation of these agricultural wastes. The characterization of the activated carbon obtained using a scanning electron microscope (SEM), Fourier-transform infrared (FTIR) spectroscopy analysis, X-ray diffraction (XRD) and the Brunauer–Emmett–Teller (BET) method revealed that the activated carbon products exhibited high porosity and the formation of various functional groups. The effects of different parameters were examined using batch adsorption experiments, such as the adsorbent masses, pH, initial pollutant concentration and contact time. The results show that the performance increased with an increased adsorbent mass (up to 0.25 g/L) and decreased initial concentration of the adsorbent tested. On the other hand, this study clearly showed that the adsorption efficiency of the MO on the raw spent coffee grounds (SCGs) waste was around 43%, while no removal was observed for the humic acid. The experiments demonstrated that the activated carbon synthesized from the used coffee grounds (the efficiency was compared with commercial activated carbon (CAC) with a difference of 13%) was a promising alternative to commercially available adsorbents for the removal of humic acid from seawater. To understand and elucidate the adsorption mechanism, various isothermal and kinetic models were studied. The adsorption capacity was analyzed by fitting experimental data to these models. The experimental data for methyl orange dyes were analyzed using Langmuir and Freundlich isothermal models. The Freundlich isotherm model provided a superior fit to the equilibrium data, as indicated by a higher correlation coefficient (R2) than that of the Langmuir model. The maximum adsorption was observed at pH 3. The Freundlich adsorption capacity was found to be 333 mg/g adsorbent. The PAC showed a high adsorption capacity for the MO and HA. The PAC showed the highest adsorption capacities for the HA and MO compared with the other adsorbents used (SCGs and CAC) and would be a good material to increase the adsorption efficiency for humic acid removal in the seawater pretreatment process. In addition, the prepared AC BET surface area was 520.40 m2/g, suggesting a high adsorption capacity. This makes the material potentially suitable for various applications that require a high surface area. These results indicate that high-quality sustainable activated carbon can be efficiently produced from coffee waste, making it suitable for a wide range of adsorbent applications targeting various pollutants.

Pyrene‐Functionalized Silicon Hybrid Porous Polymer for an Efficient Adsorption of Dyes

AbstractPyrene‐functionalized silicon hybrid porous polymer (TAPPy‐HPP). The hybrid polymer was successfully prepared via a Schiff base reaction using tetra(4‐aminophenyl)pyrene (TAPPy) and tetra(4‐formylphenyl)silane (TFS) as the building blocks.. This hybrid polymer was characterized using IR, solid‐state 13C and 29Si NMR, and elemental analysis. Its morphology was analyzed by PXRD and SEM. Thermal analysis using Thermal analysis using TGA shows that the synthetic polymer has greater thermal stability than its monomers at a temperature of 5 % weight loss (Td5 %) of 392 °C. Although TAPPy‐HPP has a Brunauer‐Emmet‐Teller surface area of 45.4 m2 g−1, it adsorbed dyes with high efficiency, particularly the anionic dye Congo Red (CR), with an adsorption capacity of up to 358 m2 g−1. Moreover, TAPPy‐HPP showed excellent recycling and regenerative properties. This polymer is a promising candidate for a fluorescent chemical sensor for the absorption of dyes due to its exceptional physiochemical stability and intense luminescence.

Innovative cellulose-lactone hybrid material for efficient rhodamine 6G dye adsorption: Synthesis and characterization

This study uses a simple solvent casting technique to offer an innovative, cost-effective synthesis of a cellulose-lactone hybrid material for Rhodamine 6G dye adsorption. The modified cellulose revealed superior adsorption competencies, triumphing a maximum dye removal efficiency of 97.8 % under neutral pH. Adsorption isotherms were best defined by the Langmuir model (R2 = 0.999), signifying monolayer adsorption, while the Freundlich model (R2 = 0.9714) suggested the existence of heterogeneous adsorption sites. Characterization methods, including FTIR, TGA, DSC, and SEM, confirmed the structural, thermal, and morphological changes induced by lactone modification, which enhanced the material's mechanical properties and adsorption efficiency. The hybrid material demonstrated excellent long-term stability, recyclability, and potential for large-scale water treatment applications. These findings emphasize the material's potential as a sustainable solution for removing organic pollutants from wastewater.

Biobased amphoteric aerogel with core-shell structure for the hierarchically efficient adsorption of anionic and cationic dyes

Efficient and simultaneous removal of anionic and cationic dyes from wastewater using low-cost and environmentally-friendly adsorbent is highly required. Herein, the carboxylated cellulose (carboxyl content: 2.97 mmol/g) derived from pomelo peel was extracted by a one-step H2O2/H2SO4-mediated oxidation method. Subsequently, a novel pomelo-peel cellulose/chitosan/sodium alginate (PCS) amphoteric aerogel with a specific core-shell structure was synthesized by multiple physical cross-linking strategies. The shell layer and core layer of the optimized P3CS0.75 aerogel can selectively adsorb cationic dyes and anionic dyes, in which, the theoretical maximum adsorption capacities were 888.27 mg/g and 1816.87 mg/g towards methylene blue (MB) and Congo red (CR), respectively. Especially, the aerogel’s core/shell layer exhibited hierarchical adsorption behavior without overlapping sites even in the binary dye systems. The adsorption performance of obtained amphoteric aerogel remained effective in a wide pH range and under different practical water systems. Moreover, the removal efficiencies for MB and CR were slightly reduced from 90.76 % and 99.66 % to 88.08 % and 91.39 %, respectively, after 5 adsorption-desorption cycles, and the aerogel’s structural integrity was also maintained due to its good compressive strength (487.16 KPa). In addition, the adsorption mechanism of PCS aerogel was investigated using adsorption kinetics, isotherm, thermodynamics, Fourier transform infrared spectroscopy, and X-ray photoelectron spectroscopy. It was proved that the adsorption process was endothermic spontaneous-monolayer adsorption driven by electrostatic attraction and hydrogen bonding. Therefore, the prepared biobased aerogel was expected to be a prospective material for removing mixed dyes from wastewater.

Hyaluronic acid-coated iron oxide nanoparticles for magnetic fluid hyperthermia and methylene blue dye removal: Preparation, physicochemical characterization, and enhancing the heating efficiency

We report here the magnetic fluid hyperthermia properties of water-dispersible hyaluronic acid-coated superparamagnetic iron oxide nanoparticles (HA-MNPs), prepared using the coprecipitation technique followed by ligand exchange. The presence of the hyaluronic acid coating is confirmed using Fourier transform infrared spectroscopy. Magneto-calorimetric studies show good field-induced heating efficiency of the HA-MNPs, where a high specific absorption rate (SAR) of ∼ 315 W/gFe is obtained for ∼ 5 wt% MNP concentration when exposed to an alternating magnetic field amplitude of ∼ 33.1 kA/m at ∼ 126 kHz. The heating efficiency is found to decrease by ∼ 33.8 % after immobilization of the MNPs within an agar matrix, which is attributed to the abrogation of Brownian relaxation. When subjected to an external DC magnetic field, the MNPs form linear chain-like structures, which causes the effective anisotropy energy density to increase. Magneto-calorimetric studies on agar-based oriented samples reveal a ∼ 19.5 % enhancement in SAR, thereby partly compensating for the loss in heating efficiency due to an increase in medium viscosity. The orientational ordering-induced enhancement in SAR is also verified using sweeping rate modified Stoner-Wohlfarth model-based calculations. In vitro cyto-toxicity studies on the HeLa cell lines reveal good cyto-compatibility of the MNPs. The negative charge on the surface of HA-coated MNPs is exploited to remove the cationic methylene blue dye from the aqueous medium, where the dye molecules are found to be physisorbed on the surface of the MNPs. The experimental findings clearly show the high induction heating efficiency, cyto-compatibility, and cationic dye-adsorption efficiency of the prepared HA-MNPs, thereby indicating the suitability of these MNPs for multi-functional applications like magnetic fluid hyperthermia and waste-water purification.

Delamination of MXene using biomolecule: An effective strategy toward the utilization of delaminated MXene as fillers in polymer composites

AbstractWith the emergence of two‐dimensional (2D) materials analogous to graphene, transition metal carbides and carbonitrides with unique desirable characteristics known as MXenes have turned out to be a hot research topic. Recent studies increasingly focus on the structure–property relationships of MXenes and their hybrid formations with other materials. The exfoliation and delamination of MXenes using various agents is gaining attention, while their application in functional composites presents another exciting research direction. However, the exfoliation of multi‐layered MXene into few‐layered nanosheets using bio‐based agents remains underexplored. In this study, tannic acid (TA) is employed as a bio‐exfoliating agent to delaminate Ti3C2Tx MXene, while optimizing the ratio of TA to achieve efficient exfoliation and dye adsorption. The MXene/TA composites demonstrated a maximum adsorption capacity of 187.264 mg/g and a removal efficiency of 93.69% for methylene blue (MB) in water, in accordance with the Langmuir isotherm model. Furthermore, MB adsorption caused MXene to coagulate into floccules, enabling easy removal via filtration. The study highlights the trifold role of tannic acid in MXene as a delaminating, antimicrobial, and adsorption‐enhancing agent, creating a multifunctional MXene‐tannic acid system. It introduces a new class of hybrid materials with effective applications in water purification. Additionally, incorporating this hybrid material into polymers can fine‐tune their properties, leveraging the synergistic effects of the trio to develop high‐performance smart polymer composites for diverse applications.Highlights Synthesis of MXene from Ti3C2Tx Optimization of the delamination efficiency of the biomolecule tannic acid Characterization of tannic acid‐MXene delaminated composites Analysis of the antibacterial efficiency of tannic acid delaminated MXene Investigation of water purification efficiency of delaminated MXene