Nitrogen Adsorption Isotherms Research Articles

Antitumoral action of carvedilol–a repositioning study of the drug incorporated into mesoporous silica MCM-41

We have studied repositioning of carvedilol (an antihypertensive drug) incorporated into MCM-41 mesoporous silica. The repositioning proposes a reduction in the slow pace of discovery of new drugs, as well as toxicological safety and a significant reduction in high research costs, making it an attractive strategy for researchers and large pharmaceutical companies. We obtained MCM-41 bytemplatesynthesis and functionalized it by post-synthesis grafting with aminopropyltriethoxysilane (APTES) only or with folic acid (FA), which gave MCM-41-APTES and MCM-41-APTES-FA, respectively. We characterized the materials by scanning and transmission electron microscopy, zeta potential (ZP) measurements, Fourier transform infrared absorption spectroscopy, x-ray diffractometry, nitrogen gas adsorption, and CHNS elemental analysis. We quantified the percentage of drug that was incorporated into the MCM-41 materials by thermogravimetric analysis and evaluated their cytotoxic activity in non-tumor human lung fibroblasts and the tumor human melanoma and human cervical adenocarcinoma cell lines by XTT salt reduction (2,3-bis-(2-methoxy-4-nitro-5-sulfophenyl)-2H-tetrazolium-5-arboxanilide). The x-ray diffractograms of the MCM-41 materials displayed low-angle peaks in the 2θrange between 2° and 3°, and the materials presented type IV nitrogen adsorption isotherms and H2 hysteresis typical of the MCM-41hexagonal network. The infrared spectra, the charge changes revealed by ZP measurements, and the CHN ratios obtained from elemental analysis showed that MCM-41 was amino-functionalized, and that carvedilol was incorporated into it. MCM-41-APTES incorporated 23.80% carvedilol, whereas MCM-41 and MCM-41-APTES-FA incorporated 18.69% and 12.71% carvedilol, respectively. Incorporated carvedilol was less cytotoxic to tumor and non-tumor cells than the pure drug. Carvedilol repositioning proved favorable and encourages further studies aimed at reducing its cytotoxicity to non-tumor cells. Such studies may allow for larger carvedilol incorporation into drug carriers or motivate the search for a new drug nanocarrier to optimize the carvedilol antitumoral activity.

Preparation of CYCU‐3/MCM‐41 Composites and Adsorption Properties for n‐Hexane

AbstractAdsorption method is one of the effective technologies for treating VOCs. Compared with activated carbon, silicon‐based materials have well‐ordered pore structure, good thermal stability and non‐flammability. In this paper, CYCU‐3/MCM‐41 composites were prepared by hydrothermal method through mixing MCM‐41 powder in situ. The nitrogen adsorption isotherms, saturation adsorption and cyclic adsorption/desorption curves of n‐hexane on CYCU‐3/MCM‐41 composites were experimentally measured. The results displayed that the CYCU‐3/MCM‐41 (3) exhibited the largest BET specific surface area (1631 m2/g). And its n‐hexane adsorption capacity was 776 mg/g, which was 19.4 % higher than that of MCM‐41, 1.42 times that of activated carbon, and 2.64 times that of molecular sieve. The kinetic fitting results showed that the pseudo‐first order kinetic model can more precisely embody the n‐hexane adsorption process on CYCU‐3/MCM‐41 composites, and the W‐M intraparticle diffusion model confirmed that intraparticle diffusion was not the only control step for the adsorption rate of n‐hexane on CYCU‐3/MCM‐41 composites. In addition, the regenerative rate of CYCU‐3/MCM‐41 (3) was over 98.9 % after ten adsorption and desorption cycles of n‐hexane, showing good desorption performance and excellent structural stability, and proving its broad application prospect in the field of VOCs treatment.

Fabricating a Robust Ultramicroporous Metal-Organic Framework for Purifying Natural Gas and Coal Mine Methane.

Purifying methane (CH4) from natural gas and coal mine methane (CMM) is of great significance but challenging in the chemical industry. Herein, a robust ultramicroporous metal-organic framework (MOF) is reported, which can be synthesized on a gram scale by stirring under room temperature. Single-component adsorption isotherms of gases (CH4, ethane (C2H6), propane (C3H8), nitrogen (N2)) and breakthrough experiments indicate that the MOF can separate CH4 efficiently from CH4/C2H6/C3H8 ternary mixture, with super high purity-CH4 production of 154.7 cm3g-1. Additionally, the MOF shows higher CH4 capacity than N2, resulting in excellent separation performance for the CH4/N2 mixture. Notably, the binding sites of gases can be precisely determined by single-crystal X-ray data, further confirmed by molecular simulation. It is found that there are multiple hydrogen bonds and C─H···π interactions between the gases and the framework. This work offers an excellent candidate material for CH4 purification with both high capacity and separation efficiency.

A CIRCULAR ECONOMY APPROACH TO PRODUCE LOW-COST BIODIESEL USING AGRO-INDUSTRIAL AND PACKING WASTES FROM MEXICO: VALORIZATION, HOMOGENEOUS AND HETEROGENEOUS REACTION ROUTES AND PRODUCT CHARACTERIZATION

This manuscript describes a circular economy approach to produce low-cost biodiesel using Tetra Pak (TP) and Mexican biomass wastes. Lipids were extracted from non-edible biomass with hexane. Corozo seeds contained 53 wt% lipids, while remaining biomass had <5 wt%. Corozo seed oil was selected to produce biodiesel with both homogeneous and heterogeneous reaction systems. A heterogeneous catalyst was synthesized from TP and its performance was compared with KOH in homogeneous systems using corozo and soybean oils. The best reaction conditions were identified through the Signal/Noise ratio analysis. TP catalyst achieved biodiesel yields of 12.7-98.11% (corozo) and 87.0-98.4% (soybean), while KOH systems showed 7.2-96.3% and 64.6-98.5%, respectively. These reactive systems were endothermic and fit to pseudo-second order kinetic model. Activation energies for KOH-catalyzed systems were 86.89 (corozo) and 43.72 (soybean) kJ/mol, while TP-catalyzed systems showed 78.31 and 105.68 kJ/mol, respectively. TP catalyst reuse was tested, and the loss of catalytic activity was attributed to active sites poisoning. Biomass, catalysts, and reaction products were characterized (e.g., FTIR, ICP, XRD, EDX-SEM, WDXRF, XPS, basicity and nitrogen adsorption isotherms). The TP catalyst showed competitive performance with respect to KOH, contributing to a sustainable biodiesel production chain viable for commercial implementation in Mexico.

Cost‐Effective Approach for Fabrication of High‐Quality Expanded Vermiculite for Alizarin Red S Removal From Aqueous Media

AbstractVermiculite is extensively utilized for several applications, including as a hydroponic substrate, for soil conditioning, oil cleansing, and addressing trace metal pollution. In this study, the expansion of natural vermiculite was easily achieved by utilizing hydrogen peroxide (H2O2) with the aid of microwave technology. The characterization of expanded vermiculite involved the use of X‐ray diffraction (XRD), thermogravimetric analysis (TGA), scanning electron microscopy (SEM), nitrogen adsorption isotherm (BET), and energy dissipation X‐rays (EDX). The vermiculite has been enlarged to have a structure resembling flakes, and its surface area measures 73.9 m2/g. The adsorption of Alizarin Red S onto expanded vermiculite was investigated under varying conditions, such as pH, starting concentration, adsorbent content, and duration of exposure. The enlarged vermiculite achieved a maximum adsorption capacity of 182.5 mg/g for Alizarin Red S. Out of the three adsorption isotherm models, both the Freundlich and Temkin models accurately describe the adsorption of Alizarin Red S onto expanded vermiculite. When studying adsorption kinetics, the second‐order adsorption kinetic model is more appropriate than the first‐order adsorption kinetic model, as indicated by an R2 value of 0.8964.

Chloride permeation resistance of sulphoaluminate cement-based composite characterized by both alternating current section and RCM methods

Sulphoaluminate cement (SAC) was widely used for rapid repair and strengthening of building structures due to its excellent quick hardening and high early strength behavior. This study developed a SAC-based engineering cement composites (ECC) with ultra-high molecular weight polyethylene (UHMWPE) and investigated its mechanical properties. Chloride ion permeability coefficient were evaluated by new alternating-current sectioning and rapid chloride migration (RCM). The mechanism of the SAC-ECC against chloride erosion were quantified using nitrogen isothermal adsorption. The results show that the fracture energy, tensile strength and strain of SAC-ECC samples are higher than that of normal ECC. The polyethylene (PE) fiber could significantly improve the flexural strength and toughness with PE fiber content of 0.75 % by volume. The hydration products generated could react with chloride ion to make it chemically stabilized, leading to reduce the chloride ion diffusion coefficient significantly. Based on microscopic analysis (SEM), the pore structure in SAC-ECC composite improved remarkedly while the volume of harmful pore decreased evidently as well. SAC-ECC developed in this paper could be poetically applied to strengthening and repair of marine concrete structures.

Transformation of Organic Cacao (Theobroma cacao) Husk into Commercial

Introduction: agroindustrial wastes can be transformed to mitigate the negative impacts associated with their disposal. In cocoa production, cocoa pod husk (CPH) constitutes between 67% and 76% of the total cocoa weight. This study focuses on the potential of CPH as a valuable resource for producing activated carbon, cellulose, and potassium hydroxide (KOH)..Objective: The objective of this research was to characterize and transform the CPH obtained from an organic crop in San Bernardo-Ibagué (Colombia) into activated carbon, cellulose, and KOH.Methods: activated carbon was produced through chemical activation using KOH, with a specific procedure for characterizing the obtained product through thermal analysis (TGA) and nitrogen adsorption and desorption isotherms. For cellulose extraction, an alkaline treatment with 2% w/w NaOH was followed by a bleaching process with 2.5% w/w sodium hypochlorite. KOH was obtained by first extracting potassium carbonate and then causticizing it.Results: activated carbon (AC) was produced with a yield of 25.6%, exhibiting a surface area of 468 m²/g, a mean pore diameter of 10.8 nm, and a total pore volume of 0.228 cm³/g, with 60% fixed carbon, 27% volatile material, 6% ash, and 6% moisture. Conclusions: the transformation of cocoa pod husk into activated carbon, cellulose, and KOH provides a sustainable approach to managing agroindustrial waste, generating valuable products with significant potential for various applications. The results obtained demonstrate the feasibility of utilizing CPH as a resource in agroindustrial processes.

Cerium-Organic Framework UiO-66(Ce) as a Support for Nanoparticulate Gold for Use in Oxidation Catalysis.

An optimised synthesis of the metal-organic framework (MOF) UiO-66(Ce) is reported using a modulator-free route, yielding ~5 g of material with high crystallinity and 22% ligand defect. Two methods developed for loading gold nanoparticles onto the MOF. The first uses a double-solvent method to introduce HAuCl4 onto UiO-66(Ce), followed by reduction under 5% H2 in N2, while the second is a novel one-pot method where HAuCl4 is added to the synthesis mixture, forming Au nanoparticles within the pores of the UiO-66(Ce) during crystallisation. Analysis using powder X-ray diffraction (PXRD), nitrogen adsorption isotherms, transmission electron microscopy and small-angle X-ray scattering (SAXS) reveals that the two-step double-solvent method yields gold crystallites on the external surface of the MOF particles that are visible by PXRD. In contrast, the one-pot method forms smaller gold crystallites, with a distribution of sizes centred on ~4 nm diameter as seen by SAXS, with evidence from PXRD for the smallest particles being present within the MOF structure. The Au-loaded UiO-66(Ce) materials are evaluated for the catalytic oxidation of vanillyl alcohol to vanillin at 60 °C. Our findings indicate that incorporating Au nanoparticles via the one-pot synthesis method, enhances redox activity, achieving 43% conversion and 90% selectivity towards vanillin.

Surface‐Modified Mesoporous V2‐xSb2xO5‐δ Ceramics for Improving the Electrostatic Chemisorption of Methylene Blue

AbstractHerein, mesoporous V2‐xSb2xO5‐δ (Sb−V−O) compounds, encompassing a compositional range of x varying between, 0.05≤x≤0.08, with orthorhombic Pmmn space group symmetry, are synthesized by high‐temperature solid‐state reaction method. Scanning electron microscopy indicated the formation of microscale rods and flakes and EDS spectra affirmed the stoichiometric precision of their composition adhering to the formulated chemical formula. Nitrogen adsorption isotherms exhibited the distinctive type IV pattern, accompanied by an H3 hysteresis loop, signifying the formation of mesoporous micro rods and flakes. Brunauer‐Emmett‐Teller measurements demonstrated an augmented surface area, ranging from 16.67–28.74 m2/g, mirroring the effect of the increase in the concentration of Sb cations. The study demonstrated complete Methylene Blue dye removal within a brief 90 minute period, highlighting its efficacy in water remediation. The adsorption kinetics was aptly described by the pseudo‐second‐order model which exhibited a high degree of fit (R2=0.99). Freundlich adsorption isotherm was used to describe the multilayer adsorption of MB dye on the Sb−V−O surface indicating an exponential increase in adsorption active sites. Enhanced cationic MB dye adsorption on negative Sb−V−O surface is attributed to the electrostatic chemisorption by the interaction of NMe2+ on the negative surface modified Sb−V−O compounds.

Characteristics of granulated activated carbon from a mixture of plant raw material waste

Relevance. The need to increase the use of renewable energy sources in the economy to reduce the harmful effects on the environment. Aim. To assess the possibility of obtaining by the thermochemical method high-quality carbon adsorbents from a granular mixture of various wastes of plant origin. Objects. Samples of illiquid lumpy birch wood, walnut shells, sunflower seed husks, flax fires, anthracite coal. Methods. Physical experiments: conductive pyrolysis, water-steam activation and differential thermal analysis. The ash content and moisture content of the samples were determined according to SS R 56881-2016 and SS 33503-2015. Nitrogen adsorption isotherms were measured using a NOVA-1200e analyzer. The equilibrium activity for toluene was determined according to SS 8703-74, the adsorption activity for iodine was determined according to SS 6217-74. The determination of the density of the granules was carried out according to SS 15139-69. Results. The authors have established rational parameters for obtaining carbon adsorbents from granules of vegetable raw materials. The specific yield of pyrolysis products of a mixture of vegetable raw materials with pyrolysis resin was determined. The specific yield of carbonization products of the granular compacted mass showed an increase of 25% in comparison with the non-compacted mixture of vegetable raw materials. Rational parameters for obtaining activated carbon with the highest adsorption capacity are granules with a density of 1200 kg/m3 with a degree of burnout of the carbonization product of 70%. It was established that the obtained samples of adsorbents from granules of plant raw materials have high adsorption characteristics comparable to activated carbons obtained from fossil raw materials.

Na-Kenyaite as Efficient Basic Blue-41 Dye Removal: Synthesis and Regeneration Studies

Na-kenyaite materials are available in nature and can easily be prepared in the laboratory. These materials exhibit interesting adsorption properties; therefore, they can be invested in the new wastewater treatment technologies. This study investigates the removal of basic blue-41 (BB-41) dye from artificially contaminated water using Na-kenyaite materials in batch mode. Firstly, Na-kenyaites were prepared by the hydrothermal process at a temperature of 150 to 170 °C for a period of 2 to 7 days using different silica sources and ratios of SiO2/NaOH/H2O. The prepared materials were characterized by different techniques such as XRD, FTIR, 29Si MAS NMR, TGA/DTA, SEM, and nitrogen adsorption isotherms. A pure Na-kenyaite phase was successfully obtained using a fumed silica source and 5SiO2/Na2O/122H2O ratio. The removal experiments of basic blue-41 estimated the effectiveness of Na-kenyaites in removing properties, investigating the influence of the solid dosage, initial basic blue-41 concentration, and solution pH or Na-kenyaite solid. Results showed optimal dye removal of around 99% at pH levels above 7. Furthermore, the estimated maximum removal capacity from the Langmuir isotherm was between 124 and 165 mg/g. The results demonstrated efficient removal by Na-kenyaites and its prominence for wastewater treatment. Finally, this study explored the regeneration and reuse of Na-kenyaites through seven cycles and reported a design of a batch adsorber system to reduce the initial concentration of 200 mg/L at different percentages.

Multifunctional CoCe/silica and CoMnCe/silica spinel ferrite nanocomposite: in vitro and in vivo evaluation for cancer therapy

Multifunctional magnetic spinel ferrite based on CoCe and CoMnCe/silica nanocomposites (NCs) were developed for targeted cancer therapeutics. The formation of spinel ferrite and co-existence of spinel ferrite/silica/chemo-drug, surface/pore size distribution, morphological features and magnetic properties were investigated using different characterization techniques. XRD pattern confirmed the pure phase of CoCe and CoMnCe spinel ferrite with estimated crystal size of 27.9 nm. After silica coating and pegylation, the crystal size of CoCe and CoMnCe increases to 36.3 nm and 76.2 nm. Nitrogen adsorption isotherm confirm an effective embedment of both spinel ferrites into silica with large surface area (653 m2/g and 718 m2/g) and uniform pore size distributions (6.1 nm and 6.9 nm). FT-IR spectra confirm the magnetic spinel ferrite/silica interactions (977, 1705 and 3410 cm−1), cisplatin functionalization (1645 cm−1) and PEG (1275–2900 cm−1). Coating SFNPswith Si and/or Cp and/or PEG, tunes the magnetic characteristics of the NCs system. For both CoCe and CoMnCe SFNPs, saturation magnetization (Ms) of 14.96 and 10.91 emu/g, residual magnetization (Mr) of 4.40 and 2.42 emu/g, Hc (coercivity) of 1072.1 and 719.3 Oe gradually diminish upon Si, respectively. The chemical state of CoMnCe SFNPs, CoCe SFNPs, their silica and active cisplatin NCs (Pt0 and Pt2+) were investigated using X-ray Photoelectron Spectroscopy (XPS). The anti-cancer efficacy of pegylated nanoformulations were tested in in vitro cells (HeLa, HCT-116 and HEK-293) and Hemolysis assay. The toxicity of different nanoformulations administered in different concentrations (20–2000 mg/kg) in in vivo was estimated based on LD50 value.

Development of a sustainability-oriented university laboratory: Insight into adsorption kinetics models for the removal of pollutants from aqueous solution

The aim of the present research is to show the development of a sustainability-oriented lab that teaches adsorption concepts in a virtual environment based on the premise “learning-through-play”. Kinetic results in the virtual environment are contrasted to those obtained experimentally when diverse adsorbents prepared from Agave Bagasse (Raw Fibers, Hydrothermal Fibers, and Activated Fibers) were synthesized. Comparison between virtual and real-life experiments involving removal of methylene blue in solution showed that a pseudo-first-order model could describe adsorption kinetics satisfactorily. The study is complemented with a characterization of the adsorbents through SEM, nitrogen adsorption isotherms, FTIR and Raman. In addition, the environmental impact of the synthesis of adsorbents was evaluated through well-known methodologies (GAPI, NEMI, and Eco-Scale), which agree that raw fibers are the most eco-friendly material. This research provides an exciting opportunity to advance our knowledge on developing new technologies for teaching in engineering and to compliment real-life practices that consider environmental impacts with virtual experiments.

Synthesis of silver‐doped TiO2 nanoparticles with highly efficient adsorption of Congo red

AbstractTiO2 nanoparticles (NPs) doped with Ag were produced through a solvothermal method, with varying amounts of silver doping ranging from 0.5% to 1.5%. The samples were analyzed for crystallite sizes, structure, and metallic bondings using XRD, SEM, EDXS, and FTIR techniques. The BET surface areas were determined through nitrogen adsorption isotherms. The efficiency of the silver‐doped TiO2 NPs for removing Congo red (CR) was tested through adsorption experiments. The results showed that the synthesized TiO2 NPs doped with Ag were uniformly spherical in shape, with tiny average sizes ranging from 7.97 to 12.74 nm and large BET surface areas (98.41–166.1 m2 g−1). The silver‐doped TiO2 samples with a 0.5% Ag doping amount exhibited the highest adsorption capacity in CR removal, with a maximum adsorption capacity of 454.55 mg of dye per gram of adsorbent and a lower contact time of 20 min than other metal oxide NPs. The CR adsorption onto 0.5% Ag‐TiO2 obeyed the Langmuir isotherm model (R2 = 0.989), and the adsorption followed a pseudo‐second‐order kinetic equation. The adsorbent could be efficiently reused for five consecutive cycles to remove CR.

Evaluation of methane adsorption isotherms at ambient temperature on carbon materials from NLDFT pore size analysis derived from standard N2 and CO2 adsorption isotherms

In this paper, we attempt to estimate CH4 adsorption on carbon materials based on the pore size distribution (PSD) characteristics evaluated from standard nitrogen and carbon dioxide adsorption isotherms using the nonlocal density functional theory (2D-NLDFT), or more precisely, its two-dimensional version (2D-NLDFT). The PSDs of the carbons were calculated by the simultaneous fit of the NLDFT models to the corresponding N2 and CO2 adsorption data. This method is referred to in the literature as the dual gas analysis method which is implemented in SAIEUS software. Essential features of carbon PSDs affecting the shapes of methane adsorption isotherms measured at ambient temperature were identified as related to micro and mesopores carbon structure. We discuss how different micro and mesopore size ranges contribute to methane adsorption isotherms in the low and higher-pressure ranges. The results of the present study may serve as guidance for selecting and designing suitable carbon materials for practical applications such as PSA recovery of CH4 from its mixtures or for methane storage.

Diffusion and chemical kinetics of methylene blue dye adsorption on silica doped with iron (III) ions

Silica are widely used in catalysis, adsorption, and chromatography. In the last decade, they have been increasingly used in medicine, however, to ensure their biocompatibility, silica need to be modified and the simplest way of such a modification is doping them with iron cations. The article presents a study of the sorption characteristics of silica doped with iron cations. The purpose of the study was to assess the effect of doping silica with iron ions on the kinetics of their adsorption of model sorbate of methylene blue dye. Doped silica were synthesised by the alkoxide sol-gel method at pH=1.5 and pH=5.0 with the introduction of iron cations into the reaction mixture during the hydrolysis of tetraethoxysilane. The iron content in the samples was 1.5, 2.3, and 3.8 at. %. According to the results of X-ray phase analysis, all samples were X-ray amorphous. According to the shape of the isotherms of low-temperature nitrogen adsorption, all samples were classified as microporous. The specific surface area of the samples and the total pore volume decreased slightly with an increase in the iron content in the samples. The adsorption of methylene blue dye was carried out at temperatures of 25, 30, and 35 °C. The kinetic adsorption curves were analysed using the following diffusion kinetics models: Boyd model (external diffusion process) and Weber-Morris model (internal diffusion process). Also, the kinetic data were analysed using kinetic models of pseudo first-order (Lagergren model) and pseudo second-order (Ho and McKay's model). It was established that all samples were characterised by a mixed-diffusion regime of the sorption process. Adsorption kinetics was adequately described by the model of pseudo-second-order.

Fabrication of new in‐situ ternary nano/microcomposite LDH/Ag2O/Bayerite in trimetallic NiAg/Al layered double hydroxides for CO2 capture material

AbstractWe reported new in‐situ ternary nano/microcomposite layered double hydroxides/Ag2O/bayerite in trimetallic NiAg/Al layered double hydroxides (LDH) via hydrothermal technique; and characterization by powder X‐ray diffraction (XRD), Fourier transforms infrared spectroscopy (FT‐IR), field emission scanning electron microscopy (FE‐SEM), energy dispersive spectroscopy (EDS), and N2 adsorption‐desorption. The formation of bayerite and silver oxide species on the LDH nanosheet depended on the excess of Al3+ and Ag+ in the solution under alkaline and hydrothermal conditions. The nitrogen isotherm adsorption profile for all ternary composites exhibited uniformity with mesoporous and lamellar characteristics. The surface area of all the composites ranged from 81.17 to 150.23 m2. g−1, the Barret‐Joyner‐Halenda (BJH) pore volume from 0.22 to 0.27 cm3. g−1, and the average pore diameter ranged from 3.47 to 5.78 nm. All composites show a laminar plate‐like structure covered with elongated pieces. The particle size of the composites ranged from 54.86 to 115.96 nm, indicating the size changed from nano to microcomposite because of the different molar ratios of Ag and Ni in the solid. The ternary composite reveals CO2 capture activity with adsorption capacity ranging from 13.93 to 19.61 mmol g−1. © 2024 Society of Chemical Industry and John Wiley &amp; Sons, Ltd.

Coin‐Shaped Carbon Prepared with Cerbera manghas Fibers via Multistage Carbonization and Activation for High‐Performance Symmetrical Supercapacitors

AbstractSupercapacitor energy storage devices and activated carbon (AC) manufacturing materials for producing high‐performance supercapacitors have received extensive attention from researchers. Biomass‐based AC has been extensively studied due to its environmental friendliness, abundant availability, porous structure, and high specific surface area. This work focuses on developing biomass‐based carbon electrodes derived from Cerbera manghas fiber (CMF) with variations in carbonization temperature to obtain optimum supercapacitor cell performance. The prepared CMF AC was characterized using energy dispersive X‐ray, Fourier transform infrared, X‐ray diffraction, scanning electron microscope, and nitrogen isothermal adsorption–desorption. CMF AC with the optimum carbonization temperature (CMF‐600) produced a fibrous structure with a lot of mesoporous so that the specific surface area and specific capacitance were high, namely, 721.495 m2 g−1 and 221 F g−1 at scan rate 1 mV s−1, respectively. The results of this study indicate that selecting the optimum temperature can enhance the performance of supercapacitor cells and make AC based on CMF biomass potential for cheap and efficient energy storage applications.

Facile synthesis of silver nanoparticles loaded spent cathodic Lithium-Ion battery components for enhanced bifunctional photocatalysis: Investigating the influence of magnetic properties

Due to resource depletion and environmental concerns regarding battery disposal, it is becoming more essential to recycle valuable metals from wasted lithium-ion batteries (LIBs). A novel approach is proposed in this study for the efficient bifunctional photocatalysis of LIBs components by integrating AgNPs in an environmentally sustainable manner via a sustainable hydrothermal process. The HRTEM and image mapping reveal a carbon matrix (C/Li3Fe5O8/Ag) with a dispersed arrangement of AgNPs (5–10 wt%). By acting as a reducing agent, graphite plays a crucial role in the transformation of Ag+ ions into AgNPs. The homogenous distribution of Ag NPs observed in the high-resolution TEM images further supports the role of graphite in the modification and decoration of Ag NPs onto the surface of the extracted spent cathode sample. The detection of a spot matching the (200) plane of Ag in the selected area electron diffraction (SAED) measurements confirms the successful formation of AgNPs. Additionally, the presence of a ring corresponding to the (110) plane of graphite in the SAED measurements suggests the coexistence of graphite with AgNPs in the composite heterostructures. The nitrogen adsorption isotherm analysis was conducted to explore the physical properties of the AgNPs@LIBs nanocomposite, providing valuable insights into its pore size distribution and Brunauer–Emmett–Teller (BET) surface area. The nanocomposites exhibited paramagnetic behavior, as revealed by vibrational sample magnetometer (VSM) measurements, with saturation magnetization values ranging from 76.3 × 10−3 to 36.13 × 10−3 emu/g. The study involved the photodegradation of oxytetracycline (OTC), a representative pharmaceutical pollutant, along with an investigation into the potential of Cr(VI) reduction. Under optimal component ratios, a significant improvement in pollutant removal was achieved under UV radiation, reaching up to 75 % for OTC and 80 % for Cr(VI), highlighting the efficiency of the process.

Organo acid-activated clays for water treatment as removal agent of Eosin-Y: Properties, regeneration, and single batch design absorber

Organoclays have been proposed as efficient removal agents for colored wastewater treatment. In this study, organo-acid-activated clays were investigated for their ability to remove eosin Y dye molecules. Firstly, the clay was acid activated using sulfuric solution at 90 °C for overnight. Secondly, the resulting materials were treated by hexadecyltetramethylammonium bromide solutions to obtain organo-acid-activated clays. Several techniques were used, such as X-ray diffraction, carbon hydrogen nitrogen analysis, silicon-29 and carbon-13 solid-state nuclear magnetic resonance, and nitrogen adsorption isotherms. The cation exchange capacity values were reduced and the specific surface area values increased from 80.1 m2/g to 183.2 m2/g during the acid activation process. The resulting organo-acid-activated clays had a similar expansion of interlayer spacing of 3.90 nm with less intercalated hexadecyltetramethylammonium surfactants, ranging from 0.80 mmol/g to 1.22 mmol/g; 13C solid NMR indicated that the intercalated surfactants exhibited different degree of conformation. Many factors, including the solid dose, solution pH, amount of intercalated surfactants, and starting eosin-Y concentrations, were studied in relation to the removal capabilities of organo acid-activated clays. Based on the Langmuir model, the removal capacity of the organo acid-activated clays ranged from a minimum of 43.5 mg/g to a maximum of 79.3 mg/g, dependent on the surfactant quantities and acid activation degree. , and the pH. The removal percentage of eosin-Y was increased from 50.5 % to 80.8 % by treating the organo acid-activated clay with HCl solution before the removal procedure. Regeneration and reuse of two selected organo acid-activated clays were carried out for seven successive cycles, and a reduction in the initial efficiency was in the range of 26.4 %–30.1 %. However, for organoclay (without acid activation), approximately 52.1 % efficiency was maintained. Using the Langmuir model and mass balance equations, a single-stage adsorber design was suggested for different dye volumes at a constant starting concentration.