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Environmental Pollution (Barking, Essex... Mar 2024The removal and recovery of uranium [U(VI)] from organic containing wastewater has been a challenging in radioactive wastewater purification. Here, we designed a...
The removal and recovery of uranium [U(VI)] from organic containing wastewater has been a challenging in radioactive wastewater purification. Here, we designed a polyamine/amidoxime polyacrylonitrile fiber (PAN-AO-A) with high removal efficiency, excellent selectivity, excellent organic resistance and low cost by combining the anti-organic properties of amidoxime polyacrylonitrile fiber (PAN-AO-A) with the high adsorption capacity of polyamine polyacrylonitrile fiber, which is used to extract U(VI) from low-level uranium-containing wastewater with high ammonia nitrogen and organic content. PAN-AO-A adsorbent with high grafting rate (86.52%), high adsorption capacity (q = 618.8 mg g), and strong resistance to organics and impurity interference is achieved. The adsorption rate of U(VI) in both real organic and laundry wastewater containing uranium is as high as 99.7%, and the partition coefficients (K) are 7.61 × 10 mL g and 9.16 × 10 mL g, respectively. The saturated adsorption capacity of PAN-AO-A in the continuous system solution can reach up to 505.5 mg g, and the concentration of U(VI) in the effluent is as low as 1 μg L. XPS analysis and Density functional theory (DFT) studies the coordination form between U(VI) and PAN-AO-A, where the most stable structure is η-AO(UO)(CO). The -NH-/-NH and -C(NH)N-OH groups of PAN-AO-A exhibit a synergistic complex effect in the U(VI) adsorption process. PAN-AO-A is a material with profound influence and limitless potential that can be used for wastewater containing U(VI) and organic matter.
Topics: Wastewater; Uranium; Polyamines; Oximes; Adsorption
PubMed: 38159627
DOI: 10.1016/j.envpol.2023.123269 -
Journal of Colloid and Interface Science Feb 2022Sacrifiers-promoted photocatalysis is a useful way to achieve high efficiency photoreduction and photocatalytic hydrogen production for photocatalysts of weak reductive...
Sacrifiers-promoted photocatalysis is a useful way to achieve high efficiency photoreduction and photocatalytic hydrogen production for photocatalysts of weak reductive power such as TiO. Herein we report a new method to fabricate a unique dyadic hybrid consisting of closely compacted crystalline (anatase) and titanium glycerolate (TiG)-derived organic group-retained amorphous nanoparticles to validate adsorption-stored sacrifiers-promoted photocatalysis instead of using sacrifiers in bulk solution. It was found that ascorbic acid (AA)-modified TiG prepared at a small fraction of glycerol, characterized by peculiar cocoon/open nanocontainer-type morphologies, varieties of oxygen containing groups, and remarkably high specific surface area, is suitable for precursing such hybrids. AA can change crystallization processes and particle morphologies by terminating chain linkages in TiG structure, which increases porosity and brings about visible light responsive photocatalysis for the dyadic hybrid. Benefiting from good adsorption affinity to organic sacrifiers, the sacrifier-prestored hybrid can catalyze significantly enhanced photoreduction with good reproducibility toward dye molecules via the synergy of sacrifier enrichment and photocatalysis. AA modified TiG also exhibits good self-reducibility enabling pre-loading of highly dispersed and localized platinum nanoparticles, and the resulted dyadic hybrid facilitates photocatalytic hydrogen production of extremely higher turn-off frequency and better impurities interference-resistivity compared to the P25-based commercial catalyst.
Topics: Catalysis; Metal Nanoparticles; Photolysis; Platinum; Reproducibility of Results; Titanium
PubMed: 34749138
DOI: 10.1016/j.jcis.2021.10.067 -
Frontiers in Chemistry 2023In this study, BaZrYMO perovskite electrolytes with sintering aids (M = Mn, Co, and Fe) were synthesized by a sustainable approach using spinach powder as a chelating...
In this study, BaZrYMO perovskite electrolytes with sintering aids (M = Mn, Co, and Fe) were synthesized by a sustainable approach using spinach powder as a chelating agent and then compared with chemically synthesized BaZrYMO (M = Mn, Co, and Fe) electrolytes for intermediate temperature SOFCs. This is the first example of such a sustainable synthesis of perovskite materials with sintering aids. Structural analysis revealed the presence of a cubic perovskite structure in BaZrYMO (M = Mn, Co, and Fe) samples synthesized by both green and conventional chemical methods. No significant secondary phases were observed in the samples synthesized by a sustainable approach. The observed phenomena of plane shift were because of the disparities between ionic radii of the dopants, impurities, and host materials. The surface morphology analysis revealed a denser microstructure for the electrolytes synthesized via green routes due to metallic impurities in the organic chelating agent. The absence of significant impurities was also observed by compositional analysis, while functional groups were identified through Fourier-transform infrared spectroscopy. Conductivity measurements showed that BaZrYMO (M = Mn, Co, and Fe) electrolytes synthesized by oxalic acid have higher conductivities compared to BaZrYMO (M = Mn, Co, and Fe) electrolytes synthesized by the green approach. The button cells employing BaZrYCoO electrolytes synthesized by the chemical and green routes achieved peak power densities 344 and 271 mW·cm respectively, suggesting that the novel green route can be applied to synthesize SOFC perovskite materials with minimal environmental impact and without significantly compromising cell performance.
PubMed: 38090348
DOI: 10.3389/fchem.2023.1322475 -
Journal of Pharmaceutical and... Jan 2022Oxytocin is not only a significant peptide drug for enhancing uterine contractions, but also an emerging biomarker and therapeutic target of mental disorders in clinical...
Oxytocin is not only a significant peptide drug for enhancing uterine contractions, but also an emerging biomarker and therapeutic target of mental disorders in clinical practice. There is a pressing need for the standardization of oxytocin assays because of its low pharmaceutical quality and large variations among measurement approaches. International System of Units (SI)-traceable analytical methods and well-characterized pure reference materials are urgently needed to set up standard reference measurement systems in laboratory medicine, ensuring the accuracy and comparability of test results. Herein, the purity assignment of a synthetic oxytocin containing a disulfide linkage was established based on a mass balance method, which had never been performed for a cross-linked peptide. An in-house validated liquid chromatography-high-resolution tandem mass spectrometry method was developed for the determination of structurally-related impurities in the study material. Twenty-one structurally-related impurities including deamidations, oxidations, and amino acid insertions, etc. ranging from 0.05 mg g to 15.65 mg g were identified and quantified by applying a hierarchy calibration concept. This study subsequently discusses a fit for purpose assessment for non-peptide related impurities including water, non-volatile counterions, inorganic elements, and volatile organic compounds that were determined using coulometric Karl Fischer titration, ion chromatography, inductively coupled plasma mass spectrometry, and headspace gas chromatography-mass spectrometry, respectively. The resulting assigned value (796.5 mg g) is determined to be traceable to SI associated with a small measurement uncertainty of 6.5 mg g (k = 2). The method developed in this study has been verified through an international key comparison jointly coordinated by the Bureau International des Poids et Mesures and the National Institute of Metrology.
Topics: Amino Acids; Chromatography, Liquid; Humans; Oxytocin; Reference Standards; Tandem Mass Spectrometry
PubMed: 34656934
DOI: 10.1016/j.jpba.2021.114401 -
Nanomaterials (Basel, Switzerland) May 2023Photovoltaics are being transformed by perovskite solar cells. The power conversion efficiency of these solar cells has increased significantly, and even higher...
Photovoltaics are being transformed by perovskite solar cells. The power conversion efficiency of these solar cells has increased significantly, and even higher efficiencies are possible. The scientific community has gained much attention due to perovskites' potential. Herein, the electron-only devices were prepared by spin-coating and introducing the organic molecule dibenzo-18-crown-6 (DC) to CsPbIBr perovskite precursor solution. The current-voltage (I-V) and J-V curves were measured. The morphologies and elemental composition information of the samples were obtained by SEM, XRD, XPS, Raman, and photoluminescence (PL) spectroscopies. The distinct impact of organic DC molecules on the phase, morphology, and optical properties of perovskite films are examined and interpreted with experimental results. The efficiency of the photovoltaic device in the control group is 9.76%, and the device efficiency gradually increases with the increase of DC concentration. When the concentration is 0.3%, the device efficiency is the best, reaching 11.57%, short-circuit current is 14.01 mA/cm, the open circuit voltage is 1.19 V, and the fill factor is 0.7. The presence of DC molecules effectively controlled the perovskite crystallization process by inhibiting the in-situ generations of impurity phases and minimizing the defect density of the film.
PubMed: 37299654
DOI: 10.3390/nano13111751 -
The Journal of Physical Chemistry... Oct 2021Narrow bandgap donor-acceptor organic semiconductors are generally considered to show a closed-shell singlet ground state, and their radicals are reported as impurities,...
Narrow bandgap donor-acceptor organic semiconductors are generally considered to show a closed-shell singlet ground state, and their radicals are reported as impurities, defects, polarons, and charge transfer monoradicals. Herein, we systematically investigated the open-shell singlet diradical electronic ground state of two diketopyrrolopyrrole-based compounds via the combination of electron spin resonance (ESR), nuclear magnetic resonance, superconducting quantum interference device magnetometry, and theoretical calculations. It is widely known that the quinoidal character will be significantly enhanced in the aggregation state accompanied by improved planarity and enhanced delocalization. We proposed an aggregation-induced radical and captodative effect as the driving force for the formation and stabilization of the open-shell quinoid diradical based on the ESR test in different proportions of mixed solvents. Our results provided a novel view for understanding the intrinsic chemical structure of donor-acceptor organic semiconductors, the open-shell singlet and thermally excited triplet electronic states, and the unexpected physical processes between the ground state and the excited state.
PubMed: 34596405
DOI: 10.1021/acs.jpclett.1c02463 -
Nature Chemistry Nov 2023The use of coordination complexes within covalent organic frameworks can significantly diversify the structures and properties of this class of materials. Here we...
The use of coordination complexes within covalent organic frameworks can significantly diversify the structures and properties of this class of materials. Here we combined coordination chemistry and reticular chemistry by preparing frameworks that consist of a ditopic (p-phenylenediamine) and mixed tritopic moieties-an organic ligand and a scandium coordination complex of similar sizes and geometries, both bearing terminal phenylamine groups. Changing the ratio of organic ligand to scandium complex enabled the preparation of a series of crystalline covalent organic frameworks with tunable levels of scandium incorporation. Removal of scandium from the material with the highest metal content subsequently resulted in a 'metal-imprinted' covalent organic framework that exhibits a high affinity and capacity for Sc ions in acidic environments and in the presence of competing metal ions. In particular, the selectivity of this framework for Sc over common impurity ions such as La and Fe surpasses that of existing scandium adsorbents.
PubMed: 37400595
DOI: 10.1038/s41557-023-01273-3 -
Journal of Hazardous Materials Sep 2021Arsenic liberation and accumulation in the groundwater environment are both affected by the presence of primary ions and soluble organic matter. The most important... (Review)
Review
Arsenic liberation and accumulation in the groundwater environment are both affected by the presence of primary ions and soluble organic matter. The most important influencing role in the co-occurrence is caused by human activity, which includes logging, agricultural runoff stream, food, tobacco, and fertilizers. Furthermore, it covers a wide range of developed and emerging technologies for removing arsenic impurities from the ecosystem, including adsorption, ion exchangers, bio sorption, coagulation and flocculation, membrane technology and electrochemical methods. This review thoroughly explores various arsenic toxicity to the atmosphere and the removal methods involved with them. To begin, the analysis focuses on the general context of arsenic outbreaks in the area, health risks associated with arsenic, and measuring techniques. The utilization of innovative functional substances such as graphite oxides, metal organic structures, carbon nanotubes, and other emerging types of composite materials, as well as the ease, reduced price, and simple operating method of the adsorbent material, are better potential alternatives for arsenic removal. The aim of this article is to examine the origins of arsenic, as well as identification and treatment methods. It also addressed recent advancements in Arsenic removal using graphite oxides, carbon nanotubes, metal organic structures, magnetic nano composites, and other novel types of usable materials. Under ideal conditions for the above methods, the arsenic removal will achieve nearly 99% in lab scale.
Topics: Adsorption; Arsenic; Ecosystem; Humans; Nanotubes, Carbon; Water; Water Pollutants, Chemical; Water Purification
PubMed: 34102361
DOI: 10.1016/j.jhazmat.2021.126299 -
Journal of Chromatographic Science May 2024Betaxolol (Bx) is a selective β1 receptor blocker used in the treatment of hypertension and glaucoma. The aim of the present work was to demonstrate an approach...
Betaxolol (Bx) is a selective β1 receptor blocker used in the treatment of hypertension and glaucoma. The aim of the present work was to demonstrate an approach involving use of liquid chromatography (LC) and liquid chromatography-electrospray ionization mass spectrometry (LC-ESI/MS) for the simultaneous separation, identification and characterization of impurities and of degradation products of betaxolol without their isolation from the reaction mixtures. At optimum condition, and according to ICH guidelines, the limit of detection (LOD) and limit of quantification (LOQ) for Bx are found to be 5.46 and 16.54 μg mL-1, respectively. However, the LOD and LOQ for the major degradation product P6 were 2.15 and 6.53 μg mL-1. Betaxolol was subjected to hydrolytic (acidic and basic) and oxidative, stress conditions according to International Conference on Harmonization (ICH) guideline Q1A (R2), and as results, the drug was found to be labile in acidic, basic and oxidative stress conditions. Based on LC-ESI/MS analysis, the found results revealed that Bx decomposes in acidic, basic and oxidizing environments. All degradation products were identified with the help of their fragmentation pattern and the masses obtained upon the MS analysis.
PubMed: 38717216
DOI: 10.1093/chromsci/bmae025 -
Angewandte Chemie (International Ed. in... Dec 2023Accidentally, it was found that triphenylamine (TPA) from commercial sources shows ultralong yellow-green room temperature phosphorescence (RTP) like commercial...
Accidentally, it was found that triphenylamine (TPA) from commercial sources shows ultralong yellow-green room temperature phosphorescence (RTP) like commercial carbazole, which however disappears for lab-synthesized TPA with high purity. Herein, we for the first time identify the impurity types that cause RTP of commercial TPA, which are two N, N-diphenyl-naphthylamine isomers. Due to similar molecular polarity and very trace amount (≈0.8 ‰, molar ratio), these naphthyl substituted impurities can be easily overlooked. We further show that even at an extremely low amount (1000000 : 1, mass ratio) of impurities, RTP emission is still generated, attributed to the triplet-to-triplet energy transfer mechanism. Notably, this doping strategy is also applicable to the triphenylphosphine and benzophenone host systems, of which strong RTP emission can be activated by simply doping the corresponding naphthyl substituted analogues into them. This work therefore provides a general and efficient host/guest strategy toward high performance and diverse organic RTP materials.
PubMed: 37905301
DOI: 10.1002/anie.202315911