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Environmental Science and Pollution... Jul 2024In this study, novel adsorbents were synthesized via the activation and magnetization of carbon spheres, graphene, and carbon nanotubes fabricated from plastics to...
In this study, novel adsorbents were synthesized via the activation and magnetization of carbon spheres, graphene, and carbon nanotubes fabricated from plastics to improve their surface area and porosity and facilitate their separation from aqueous solutions. Fourier transform infrared spectroscopy "FTIR", X-ray diffraction "XRD", energy-dispersive X-ray spectroscopy "EDX", transmission electron microscope "TEM", and X-ray photoelectron spectroscopy "XPS" affirmed the successful activation and magnetization of the fabricated materials. Further, surface area analysis showed that the activation and magnetization enhanced the surface area. The weight loss ratio decreased from nearly 60% in the case of activated graphene to around 25% after magnetization, and the same trend was observed in the other materials confirming that magnetization improved the thermal stability of the fabricated materials. The prepared carbonaceous materials showed superparamagnetic properties according to the magnetic saturation values obtained from vibrating sample magnetometry analysis, where the magnetic saturation values were 33.77, 38.75, and 27.18 emu/g in the presence of magnetic activated carbon spheres, graphene, and carbon nanotubes, respectively. The adsorption efficiencies of methylene blue (MB) were 76.9%, 96.3%, and 74.8% in the presence of magnetic activated carbon spheres, graphene, and carbon nanotubes, respectively. This study proposes efficient adsorbents with low cost and high adsorption efficiency that can be applied on an industrial scale to remove emerging pollutants.
PubMed: 38954341
DOI: 10.1007/s11356-024-33729-5 -
Environmental Science and Pollution... Jul 2024A novel 3D nitrogen-doped porous carbon supported Fe-Cu bimetallic nanoparticles composite (Fe-Cu-N-PC) was prepared via direct pyrolysis by employing black liquor...
A novel 3D nitrogen-doped porous carbon supported Fe-Cu bimetallic nanoparticles composite derived from lignin: an efficient peroxymonosulfate activator for naphthalene degradation.
A novel 3D nitrogen-doped porous carbon supported Fe-Cu bimetallic nanoparticles composite (Fe-Cu-N-PC) was prepared via direct pyrolysis by employing black liquor lignin as a main precursor, and it was utilized as a novel catalyst for PMS activation in degrading naphthalene. Under the optimum experimental conditions, the naphthalene degradation rate was up to 93.2% within 60 min in the Fe-Cu-N-PC/PMS system. The porous carbon framework of Fe-Cu-N-PC could facilitate the quick molecule diffusion of reactants towards the inner bimetallic nanoparticles and enriched naphthalene molecules from the solution by a specific adsorption, which increased the odds of contact between naphthalene and reactive oxygen species and improved the reaction efficiency. The quenching reaction proved that the non-free radical pathway dominated by O was the main way in naphthalene degradation, while the free radical pathway involving SO and ·OH only played a secondary role. Moreover, owing to its high magnetization performance, Fe-Cu-N-PC could be magnetically recovered and maintained excellent naphthalene degradation rate after four degradation cycles. This research will offer a theoretical basis for the construction of facile, efficient, and green technologies to remediate persistent organic pollutants in the environment.
PubMed: 38954339
DOI: 10.1007/s11356-024-34147-3 -
Environmental Science and Pollution... Jul 2024The functionalization of nanoparticles with 2D nanosheets is an effective approach to enhance their functional properties for pollutant removal. This research outlines...
The functionalization of nanoparticles with 2D nanosheets is an effective approach to enhance their functional properties for pollutant removal. This research outlines the synthesis of a 2D-delaminated molybdenum carbide (MXene) chitosan nanocomposite (2D-d-MoCTx-Cs NC) with bacterial control and photocatalytic properties for dye adsorption. The nanocomposite includes Tx-surface terminating groups O, OH, and F. In this investigation, the composite was synthesized using the etching method and its formation was confirmed through UV spectra at 288 nm. It was characterized through FTIR, XRD, Particle size, Zetapotential, FESEM, HRTEM, EDAX, and XPS analyses. FTIR spectral analysis of NC suggests that amines are formed through a Schiff base reaction between glutaraldehyde and Cs, or through the interaction of terminal aldehydes and carbonyl groups. The XRD analysis confirmed the crystalline structure of the composite. FESEM images revealed irregularly structured nanosheets (NSs) material in the prepared 2D-d-MoCTx-Cs NC samples. HRTEM images revealed 2D-d-MoCTx NSs impregnated onto Cs with an average size of 50 nm, as confirmed by a particle size analyzer, with a zeta potential value of - 15 mV. Additionally, Mo, C, N, and O are the most significant elements present in the NC, as confirmed by EDAX and XPS analyses. Further, biocompatibility testing of 2D-d-MoCTx-Cs NC yielded positive results. Moreover, under sunlight, the composites effectively adsorbed methylene blue with a 90% adsorption capacity, as confirmed by kinetic studies. Furthermore, the synergistic effect of Cs and d-MoCTx NSs resulted in significant antibacterial (50-200 µl of 1 mg/ml) and antibiofilm activity (100 µl of 1 mg/ml) against pathogenic bacteria. Furthermore, this study represents the first report on the use of 2D-d-MoCTx-Cs NC for daylight-influenced photocatalytic applications with a bacteria-controlling effect.
PubMed: 38954335
DOI: 10.1007/s11356-024-33886-7 -
Journal of Molecular Modeling Jul 2024This study primarily investigates the changes in carbon adsorption capacity and hydrogen adsorption capacity on the anode catalyst surface when using methane fuel and...
CONTEXT
This study primarily investigates the changes in carbon adsorption capacity and hydrogen adsorption capacity on the anode catalyst surface when using methane fuel and mixed gas fuel as the anode fuel for SOFC systems. To reduce the carbon adsorption capacity of the commonly used anode catalyst-nickel-based catalysts-towards hydrocarbon fuels, copper and gold are doped into the nickel-based catalysts to compare the effects on carbon and hydrogen adsorption capacities. Moreover, aside from calculating the carbon and hydrogen adsorption capacities, this project also evaluates the impact of mixed gas effects and doping effects on SOFC performance through the analysis of hydrogen diffusion coefficients and performance polarization curves. The findings reveal a noteworthy enhancement in the diffusion coefficient of syngas within the Au-doped Ni catalyst, showing an improvement of up to 45.46% at 973 K. Furthermore, the electrical power generated by syngas in the Au-doped Ni catalyst at 973 K demonstrates an increase of up to 12.06%.
METHODS
This study primarily employs DFT to calculate the carbon and hydrogen adsorption energies on methane, utilizing CASTEP for the calculations. During these calculations, the adsorption energy is determined through a three-layer surface approach, in conjunction with the Kohn-Sham equations, combining the Generalized Gradient Approximation and ultrasoft pseudopotentials for TS-search calculations. On the other hand, this project will analyze the diffusion coefficient of hydrogen on the anode catalyst using MD methods combined with the ReaxFF potential field, with GULP being utilized to complete all dynamics calculation theories. Finally, the project will analyze the performance of SOFC cells, incorporating relevant numerical equations with Matlab for numerical analysis.
PubMed: 38954107
DOI: 10.1007/s00894-024-06044-6 -
Journal of Molecular Modeling Jul 2024The bandgap modulation and electronic properties modulation of two-dimensional HfSiN monolayer induced by strain, electric field and atomic adsorption are studied by...
The bandgap modulation and electronic properties modulation of two-dimensional HfSiN monolayer induced by strain, electric field and atomic adsorption are studied by first principles. The HfSiN monolayer was found to be dynamically, thermally, and mechanically stable at equilibrium, and it is a direct semiconductor with a bandgap of 1.87 eV. The bandgap of the HfSiN monolayer can be precisely modulated by strain. Under the action of strain, HfSiN monolayer not only transforms from direct semiconductor to indirect semiconductor, but also improves the absorption of visible light. An external electric field in the 0-0.5 eV/Å range can also modulate the bandgap of HfSiN monolayer from 1.87 eV to 0 eV, and most importantly, at an external electric field of 0.5 eV/Å, HfSiN monolayer shows the characteristics of spin gapless semiconductor. The calculated adsorption energy shows that the structures of H, O and F atoms adsorbed by HfSiN monolayer can all exist stably. The bandgap of the configuration after adsorption of O and F atoms is significantly reduced compared with that of HfSiN monolayer. Furthermore, the HfSiN monolayer after adsorption of H and F atoms is transformed into a magnetic semiconductor. METHOD: All calculations were performed using Vienna ab initial simulation package, The electronic structure, mechanical properties, electronic properties and other properties were carried out using generalized gradient approximation (GGA-PBE), supplemented by HSE06 and GGA + U. The total-energy and force convergence are less than 10 eV and 0.001 eV/Å, respectively. The vacuum on the z-axis is selected 20 Å. The vdW interactions were corrected using the Grimme scheme (DFT-D3).
PubMed: 38954080
DOI: 10.1007/s00894-024-06042-8 -
Environmental Monitoring and Assessment Jul 2024The activated carbon was produced in the first phase of this investigation by chemically activating hazelnut shell waste with HPO. Composite materials were obtained by...
The activated carbon was produced in the first phase of this investigation by chemically activating hazelnut shell waste with HPO. Composite materials were obtained by coating the activated carbon with zinc oxide, whose BET surface area was calculated as 1278 m g. ZnO-doped ZnO/AC composite was synthesized as an adsorbent for its possible application in the elimination of organic dyestuff MB, and its removal efficiency was investigated. Morphological properties of ZnO/AC were characterized using analytical methods such as XRD, SEM, and BET. The adsorption system and its parameters were investigated and modeled using the response surface method of batch adsorption experiments. The experimental design consisted of three levels of pH (3, 6.5, and 10), initial MB concentration (50, 100, and 150 mg L), dosage (0.1, 0.3, and 0.5 g 100 mL), and contact time (5, 50, and 95 min). The results from the RSM suggested that the MB removal efficiency was 98.7% under the optimum conditions of the experimental factors. The R value, which expresses the significance of the model, was determined as 99.05%. Adsorption studies showed that the equilibrium data fit well with the Langmuir isotherm model compared to Freundlich. The maximum adsorption capacity was calculated as 270.70 mg g.
Topics: Adsorption; Charcoal; Water Pollutants, Chemical; Methylene Blue; Zinc Oxide; Waste Disposal, Fluid; Kinetics; Water Purification; Coloring Agents; Zinc
PubMed: 38954055
DOI: 10.1007/s10661-024-12766-0 -
The Journal of Physical Chemistry. B Jul 2024Specific ion effects in the interactions of monovalent anions with amine groups─one of the hydrophilic moieties found in proteins─were investigated using...
Specific ion effects in the interactions of monovalent anions with amine groups─one of the hydrophilic moieties found in proteins─were investigated using octadecylamine monolayers floating at air-aqueous solution interfaces. We find that at solution pH 5.7, larger monovalent anions induce a nonzero pressure starting at higher areas/molecules, i.e., a wider "liquid expanded" region in the monolayer isotherms. Using X-ray fluorescence at near total reflection (XFNTR), an element- and surface-specific technique, ion adsorption to the amines at pH 5.7 is confirmed to be ion-specific and to follow the conventional Hofmeister series. However, at pH 4, this ion specificity is no longer observed. We propose that at the higher pH, the amine headgroups are only partially protonated, and large polarizable ions such as iodine are better able to boost amine protonation. At the lower pH, on the other hand, the monolayer is fully protonated, and electrostatic interactions dominate over ion specificity. These results demonstrate that ion specificity can be modified by changing the experimental conditions.
PubMed: 38953612
DOI: 10.1021/acs.jpcb.4c02359 -
Journal of the American Chemical Society Jul 2024Direct air capture (DAC) shows considerable promise for the effective removal of CO; however, materials applicable to DAC are lacking. Among metal-organic framework...
Direct air capture (DAC) shows considerable promise for the effective removal of CO; however, materials applicable to DAC are lacking. Among metal-organic framework (MOF) adsorbents, diamine-Mg(dobpdc) (dobpdc = 4,4-dioxidobiphenyl-3,3'-dicarboxylate) effectively removes low-pressure CO, but the synthesis of the organic ligand requires high temperature, high pressure, and a toxic solvent. Besides, it is necessary to isolate the ligand for utilization in the synthesis of the framework. In this study, we synthesized a new variant of extended MOF-74-type frameworks, M(hob) (M = Mg, Co, Ni, and Zn; hob = 5,5'-(hydrazine-1,2-diylidenebis(methanylylidene))bis(2-oxidobenzoate)), constructed from an azine-bonded organic ligand obtained through a facile condensation reaction at room temperature. Functionalization of Mg(hob) with -methylethylenediamine, -ethylethylenediamine, and ,'-dimethylethylenediamine (mmen) enables strong interactions with low-pressure CO, resulting in top-tier adsorption capacities of 2.60, 2.49, and 2.91 mmol g at 400 ppm of CO, respectively. Under humid conditions, the CO capacity was higher than under dry conditions due to the presence of water molecules that aid in the formation of bicarbonate species. A composite material combining mmen-Mg(hob) and polyvinylidene fluoride, a hydrophobic polymer, retained its excellent adsorption performance even after 7 days of exposure to 40% relative humidity. In addition, the one-pot synthesis of Mg(hob) from a mixture of the corresponding monomers is achieved without separate ligand synthesis steps; thus, this framework is suitable for facile large-scale production. This work underscores that the newly synthesized Mg(hob) and its composites demonstrate significant potential for DAC applications.
PubMed: 38953459
DOI: 10.1021/jacs.4c05318 -
Applied and Environmental Microbiology Jul 2024tarch tilization ystem (Sus)D-homologs are well known for their carbohydrate-binding capabilities and are part of the operon in microorganisms affiliated with the...
UNLABELLED
tarch tilization ystem (Sus)D-homologs are well known for their carbohydrate-binding capabilities and are part of the operon in microorganisms affiliated with the phylum Bacteroidota. Until now, SusD-like proteins have been characterized regarding their affinity toward natural polymers. In this study, three metagenomic SusD homologs (designated SusD1, SusD38489, and SusD70111) were identified and tested with respect to binding to natural and non-natural polymers. SusD1 and SusD38489 are cellulose-binding modules, while SusD70111 preferentially binds chitin. Employing translational fusion proteins with superfolder GFP (sfGFP), pull-down assays, and surface plasmon resonance (SPR) has provided evidence for binding to polyethylene terephthalate (PET) and other synthetic polymers. Structural analysis suggested that a Trp triad might be involved in protein adsorption. Mutation of these residues to Ala resulted in an impaired adsorption to microcrystalline cellulose (MC), but not so to PET and other synthetic polymers. We believe that the characterized SusDs, alongside the methods and considerations presented in this work, will aid further research regarding bioremediation of plastics.
IMPORTANCE
SusD1 and SusD38489 can be considered for further applications regarding their putative adsorption toward fossil-fuel based polymers. This is the first time that SusD homologs from the polysaccharide utilization loci (PUL), largely described for the phylum Bacteroidota, are characterized as synthetic polymer-binding proteins.
PubMed: 38953372
DOI: 10.1128/aem.00933-24 -
ACS Applied Materials & Interfaces Jul 2024The efficient harnessing of solar power for water treatment via photocatalytic processes has long been constrained by the challenge of understanding and optimizing the...
The efficient harnessing of solar power for water treatment via photocatalytic processes has long been constrained by the challenge of understanding and optimizing the interactions at the photocatalyst surface, particularly in the presence of nontarget cosolutes. The adsorption of these cosolutes, such as natural organic matter, onto photocatalysts can inhibit the degradation of pollutants, drastically decreasing the photocatalytic efficiency. In the present work, computational methods are employed to predict the inhibitory action of a suite of small organic molecules during TiO photocatalytic degradation of -chlorobenzoic acid (CBA). Specifically, tryptophan, coniferyl alcohol, succinic acid, gallic acid, and trimesic acid were selected as interfering agents against CBA to observe the resulting competitive reaction kinetics via bulk and surface phase reactions according to Langmuir-Hinshelwood adsorption dynamics. Experiments revealed that trimesic and gallic acids were most competitive with CBA, followed by succinic acid. Density functional theory (DFT) and machine learning interatomic potentials (MLIPs) were used to investigate the molecular basis of these interactions. The computational findings showed that while the type of functional group did not directly predict adsorption affinity, the spatial arrangement and electronic interactions of these groups significantly influenced adsorption dynamics and corresponding inhibitory behavior. Notably, MLIPs, derived by fine-tuning models pretrained on a vastly larger dataset, enabled the exploration of adsorption behaviors over substantially longer periods than typically possible with conventional ab initio molecular dynamics, enhancing the depth of understanding of the dynamic interaction processes. Our study thus provides a pivotal foundation for advancing photocatalytic technology in environmental applications by demonstrating the critical role of molecular-level interactions in shaping photocatalytic outcomes.
PubMed: 38953235
DOI: 10.1021/acsami.4c02334