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1.
Chem Soc Rev ; 53(3): 1592-1623, 2024 Feb 05.
Artigo em Inglês | MEDLINE | ID: mdl-38167687

RESUMO

Supramolecular chemistry combines the strength of molecular assembly via various molecular interactions. Hydrogen bonding facilitated self-assembly with the advantages of directionality, specificity, reversibility, and strength is a promising approach for constructing advanced supramolecules. There are still some challenges in hydrogen bonding based supramolecular polymers, such as complexity originating from tautomerism of the molecular building modules, the assembly process, and structure versatility of building blocks. In this review, examples are selected to give insights into multiple hydrogen bonding driven emerging supramolecular architectures. We focus on chiral supramolecular assemblies, multiple hydrogen bonding modules as stimuli responsive sources, interpenetrating polymer networks, multiple hydrogen bonding assisted organic frameworks, supramolecular adhesives, energy dissipators, and quantitative analysis of nano-adhesion. The applications in biomedical materials are focused with detailed examples including drug design evolution for myotonic dystrophy, molecular assembly for advanced drug delivery, an indicator displacement strategy for DNA detection, tissue engineering, and self-assembly complexes as gene delivery vectors for gene transfection. In addition, insights into the current challenges and future perspectives of this field to propel the development of multiple hydrogen bonding facilitated supramolecular materials are proposed.


Assuntos
Materiais Biocompatíveis , Polímeros , Ligação de Hidrogênio , Polímeros/química
2.
J Environ Sci (China) ; 140: 279-291, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38331508

RESUMO

Methane is one of the major greenhouse gases (GHGs) and agriculture is recognized as its primary emitter. Methane accounting is a prerequisite for developing effective agriculture mitigation strategies. In this review, methane accounting methods and research status for various agricultural emission source including rice fields, animal enteric fermentation and livestock and poultry manure management were overview, and the influencing factors of each emission source were analyzed and discussed. At the same time, it analyzes the different research efforts involving agricultural methane accounting and makes recommendations based on the actual situation. Finally, mitigation strategies based on accounting results and actual situation are proposed. This review aims to provide basic data and reference for agriculture-oriented countries and regions to actively participate in climate action and carry out effective methane emission mitigation.


Assuntos
Gases de Efeito Estufa , Metano , Animais , Agricultura/métodos , Metano/análise , Óxido Nitroso/análise , Aves Domésticas , Gado
3.
Nat Prod Rep ; 39(6): 1282-1304, 2022 06 22.
Artigo em Inglês | MEDLINE | ID: mdl-35587693

RESUMO

Covering up to 2022Gossypol is a polyphenolic compound isolated from cottonseed. There are two optical enantiomers of gossypol, (-)-gossypol and (+)-gossypol. Gossypol exists as three different tautomers, aldehyde, ketone and lactol. Gossypol is toxic and provides a protective mechanism for cotton plants against pests. Gossypol was used as a male contraceptive in China in the 1970s. It was eventually abandoned due to noticeable side effects, disruption of potassium uptake and incomplete reversibility. Gossypol has gained considerable research interest due to its attractive biological activities, especially antitumor and antivirus. Gossypol derivatives are prepared by a structural modification to reduce toxicity and improve their therapeutic effect. This review depicts the bioactivity and regulation mechanisms of gossypol and its derivatives as drug lead compounds, with emphasis on its antitumor mechanism. The design and synthesis of pharmacologically active derivatives based on the structure of gossypol, such as gossypol Schiff bases, apogossypol, gossypolone, are thoroughly discussed. This review aims to serve as a reference for gossypol-based drug discovery and drug design.


Assuntos
Gossipol , Desenho de Fármacos , Descoberta de Drogas , Gossipol/química , Gossipol/farmacologia , Humanos , Masculino , Bases de Schiff/química , Estereoisomerismo
4.
Langmuir ; 37(12): 3637-3647, 2021 03 30.
Artigo em Inglês | MEDLINE | ID: mdl-33740370

RESUMO

Wettability is a crucial characteristic of materials that plays a vital role in surface engineering. Surface modification is the key to changing the wettability of materials, and a simple and universal modification approach is being extensively pursued by researchers. Recently, metal-phenolic networks (MPNs) have been widely studied because they impart versatility and functionality in surface modification. However, an MPN is not stable for long periods, especially under acidic conditions, and is susceptible to pollution by invasive species. Spurred by the versatility of MPNs and various functionalities achieved by silanization, we introduce a general strategy to fabricate functionally stable coatings with controllable surface wettability by combining the two methods. The formation process of MPN and silane-MPN coatings was characterized by spectroscopic ellipsometry (SE), UV-visible-near-infrared (UV-vis-NIR) spectroscopy, X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), atomic force microscopy (AFM), water contact angle (WCA), etc. We found that the stability of the MPN was greatly enhanced after silanization, which is attributed to the cross-linking effect that occurs between silane and the MPN, namely, the cross-linking protection produced in this case. Additionally, the wettability of an MPN can be easily changed through our strategy. We trust that our strategy can further extend the applications of MPNs and points toward potential prospects in surface modification.

5.
Mol Pharm ; 17(7): 2487-2498, 2020 07 06.
Artigo em Inglês | MEDLINE | ID: mdl-32469222

RESUMO

Fully effective vaccines must induce both potent humoral and cellular immunities. Nanoparticles coencapsulating antigens and adjuvants have shown promising advantages as subunit vaccines in many aspects. However, the low loading efficiency and complicated synthesis process of these nanomaterials need to be improved. Here, we utilized hexahistidine (His6)-metal assembly (HmA) particles as carriers to codeliver ovalbumin peptides and cytosine-phosphate-guanine oligodeoxynucleotides (CpG ODNs). We found that antigen/adjuvant-carrying HmA can efficiently enter into antigen-presenting cells and help the antigens escape from lysosomes to induce the maturation of these cells in vitro, characterized by increasing expression levels of costimulatory molecules and cytokines. More importantly, the vaccines with high biocompatibility can elicit strong humoral and cellular immunities by improving secretion of specific antibodies and cytokines, enhancing activation of DCs and T cells in vivo. Our results suggest that HmA provides a new approach for subunit vaccines by codelivery of antigens and adjuvants.


Assuntos
Adjuvantes Imunológicos/química , Histidina/química , Nanopartículas Metálicas/química , Oligodesoxirribonucleotídeos/imunologia , Oligopeptídeos/química , Ovalbumina/imunologia , Vacinas de Subunidades Antigênicas/química , Animais , Anticorpos/imunologia , Sobrevivência Celular/efeitos dos fármacos , Citocinas/metabolismo , Células Dendríticas/efeitos dos fármacos , Células Dendríticas/imunologia , Feminino , Imunidade Celular/efeitos dos fármacos , Imunidade Humoral/efeitos dos fármacos , Macrófagos/efeitos dos fármacos , Macrófagos/imunologia , Nanopartículas Metálicas/toxicidade , Nanopartículas Metálicas/ultraestrutura , Camundongos , Camundongos Endogâmicos C57BL , Microscopia Eletrônica de Varredura , Oligodesoxirribonucleotídeos/administração & dosagem , Ovalbumina/administração & dosagem , Células RAW 264.7 , Linfócitos T/efeitos dos fármacos , Linfócitos T/imunologia
6.
Chem Rec ; 20(6): 513-540, 2020 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-31631504

RESUMO

Heterogeneous catalysis plays a key role in promoting green chemistry through many routes. The functionalizable reactive silanols highlight silica as a beguiling support for the preparation of heterogeneous catalysts. Metal active sites anchored on functionalized silica (FS) usually demonstrate the better dispersion and stability due to their firm chemical interaction with FSs. Having certain functional groups in structure, FSs can act as the useful catalysts for few organic reactions even without the need of metal active sites which are termed as the covetous reusable organocatalysts. Magnetic FSs have laid the platform where the effortless recovery of catalysts is realized just using an external magnet, resulting in the simplified reaction procedure. Using FSs of multiple functional groups, we can envisage the shortened reaction pathway and, reduced chemical uses and chemical wastes. Unstable bio-molecules like enzymes have been stabilized when they get chemically anchored on FSs. The resultant solid bio-catalysts exhibited very good reusability in many catalytic reactions. Getting provoked from the green chemistry aspects and benefits of FS-based catalysts, we confer the recent literature and progress focusing on the significance of FSs in heterogeneous catalysis. This review covers the preparative methods, types and catalytic applications of FSs. A special emphasis is given to the metal-free FS catalysts, multiple FS-based catalysts and magnetic FSs. Through this review, we presume that the contribution of FSs to green chemistry can be well understood. The future perspective of FSs and the improvements still required for implementing FS-based catalysts in practical applications have been narrated at the end of this review.

7.
Molecules ; 24(7)2019 Apr 02.
Artigo em Inglês | MEDLINE | ID: mdl-30987000

RESUMO

The stability of gossypol was investigated by the spectroscopic method. Gossypol was dissolved in three different solvents (CHCl3, DMSO, and CH3OH) under different storage conditions (dark and with nitrogen protection, natural light and with nitrogen protection, ambient air conditions) for different time intervals (0 days, 3 days, 5 days, 7 days, 15 days, 30 days, and 45 days) at room temperature. Then, the stability of gossypol was investigated by ¹H NMR, UV-vis, and HPLC-QTOF-MS spectrometry. Results showed that gossypol existed in aldehyde-aldehyde form in chloroform within five days. Then, both aldehyde-aldehyde and lactol-lactol tautomeric forms existed and maintained a stable solution for 45 days. Gossypol dissolved in methanol mainly existed in aldehyde-aldehyde form. Only a tiny amount of lactol-lactol was found in freshly prepared methanol solution. Gossypol was found to only exist in lactol-lactol form between 30-45 days. Gossypol existed in aldehyde-aldehyde, lactol-lactol, and ketol-ketol forms in dimethyl sulfoxide, and there was a competitive relationship between aldehyde-aldehyde and lactol-lactol form during the 45 days. Among all the solvents and conditions studied, gossypol was found to be highly stable in chloroform. Under the tested conditions, the natural light and atmospheric oxygen had little effect on its stability. Although the spectroscopy data seemed to be changed over time in the three different solvents, it was actually due to the tautomeric transformation rather than molecular decomposition.


Assuntos
Gossipol/química , Cromatografia Líquida de Alta Pressão/métodos , Espectroscopia de Ressonância Magnética/métodos , Estrutura Molecular
8.
Molecules ; 24(24)2019 Dec 04.
Artigo em Inglês | MEDLINE | ID: mdl-31817148

RESUMO

Polymerization mother liquid (PML) is one of the main sources of wastewater in the chlor-alkali industry. The effective degradation of the PML produced in PVC polymerization using three or five ozone reactors in tandem was designed with a focus on improving the ozonation efficiency. The ozonation efficiency of the tandem reactors for the degradation of PML, along with the effect of ozone concentration, the number of reactors utilized in series, and the reaction time on the chemical oxygen demand (COD) removal were investigated in detail. The results showed that the COD removal increased as the ozone concentration was increased from 10.6 to 60 mg·L-1, achieving 66.4% COD removal at ozone concentration of 80.6 mg·L-1. However, when the ozone concentration was increased from 60 mg·L-1 to 80 mg·L-1, the COD removal only increased very little. The COD decreased with increasing ozone concentration. During the initial degradation period, the degradation rate was the highest at both low and high ozone concentrations. The degradation rate decreased with reaction time. The rate at a low ozone concentration decreased more significantly than at high ozone concentration. Although high ozone concentration is desirable for COD removal and degradation rate, the utilization efficiency of ozone decreased with increasing ozone concentration. The ozone utilization efficiency of the five-reactor device was three times higher than that of three tandem reactors, demonstrating that ozonation utilization efficiency can be improved by increasing the number of tandem reactors. Ozonation in tandem reactors is a promising approach for PML treatment.


Assuntos
Ozônio/química , Polimerização , Cloreto de Polivinila/química , Purificação da Água/instrumentação , Purificação da Água/métodos , Biodegradação Ambiental , Análise da Demanda Biológica de Oxigênio , Modelos Teóricos , Oxirredução , Fatores de Tempo
9.
J Mol Recognit ; 31(3)2018 03.
Artigo em Inglês | MEDLINE | ID: mdl-28326626

RESUMO

Molecularly imprinted polymers (MIPs) were designed and prepared via bulk thermal polymerization with gossypol as the template molecule and dimethylaminoethyl methacrylate as the functional monomer. The morphology and microstructures of MIPs were characterized by scanning electron microscope and Brunauer-Emmett-Teller surface areas. Static adsorption tests were performed to evaluate adsorption behavior of gossypol by the MIPs. It was found that adsorption kinetics and adsorption isotherms data of MIPs for gossypol were fit well with the pseudo-second-order model and Freundlich model, respectively. Scatchard analysis showed that heterogeneous binding sites were formed in the MIPs, including lower-affinity binding sites with the maximum adsorption of 252 mg/g and higher-affinity binding sites with the maximum adsorption of 632 mg/g. Binding studies also revealed that MIPs had favorable selectivity towards gossypol compared with non-imprinted polymers. Furthermore, adsorption capacity of MIPs maintained above 90% after 5 regeneration cycles, indicating MIPs were recyclable and could be used multiple times. These results demonstrated that prepared MIPs could be a promising functional material for selective adsorption of gossypol.


Assuntos
Gossipol/isolamento & purificação , Metacrilatos/química , Impressão Molecular , Polímeros/química , Adsorção , Sítios de Ligação , Gossipol/química , Polimerização , Polímeros/síntese química , Extração em Fase Sólida , Espectroscopia de Infravermelho com Transformada de Fourier
10.
J Mol Recognit ; 31(3)2018 03.
Artigo em Inglês | MEDLINE | ID: mdl-28332252

RESUMO

Roxarsone, one of feed add drugs containing arsenic, has been most widely used in poultry and swine industry. Roxarsone discharged into the environment has caused serious pollution problem. Herein, a reusable functional material for selective recognition and adsorption of roxarsone and its derivatives were designed and synthesized. The interaction mechanism is based on acid-base interaction and surface molecular imprinting. Dual functionalized core-shell structure with silica gel as the core was prepared to use as carrier for surface molecularly imprinted polymers. Surface molecularly imprinted polymers for roxarsone was successfully designed and synthesized using 3-aminopropyltriethoxysilane and methyl acryloyloxypropyltriethoxy silane as functional monomers, Ethylene glycol dimethacrylate as crosslinker, Azobisisobutyronitrile as initiator, acetonitrile as solvent. Binding study showed that the recognition selectivity for roxarsone and its derivatives can be significantly improved (3.5-4 folds) with molecular imprinting. Moreover, the prepared functional material for selective recognition and adsorption of Roxarsone was reusable for multiple times without significant decreasing their adsorption capacities.


Assuntos
Impressão Molecular , Compostos Orgânicos/química , Aves Domésticas , Roxarsona/química , Animais , Arsênio/química , Arsênio/toxicidade , Nitrilas/química , Polímeros/química , Propilaminas/química , Ligação Proteica , Roxarsona/análogos & derivados , Silanos/química , Propriedades de Superfície
11.
J Mol Recognit ; 27(7): 448-57, 2014 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-24895277

RESUMO

A new method of characterizing molecularly imprinted polymers (MIPs) was developed and tested, which provides a more accurate means of identifying and measuring the molecular imprinting effect. In the new polar solvent titration method, a series of imprinted and non-imprinted polymers were prepared in solutions containing increasing concentrations of a polar solvent. The polar solvent additives systematically disrupted the templation and monomer aggregation processes in the prepolymerization solutions, and the extent of disruption was captured by the polymerization process. The changes in binding capacity within each series of polymers were measured, providing a quantitative assessment of the templation and monomer aggregation processes in the imprinted and non-imprinted polymers. The new method was tested using three different diphenyl phosphate imprinted polymers made using three different urea functional monomers. Each monomer had varying efficiencies of templation and monomer aggregation. The new MIP characterization method was found to have several advantages. To independently verify the new characterization method, the MIPs were also characterized using traditional binding isotherm analyses. The two methods appeared to give consistent conclusions. First, the polar solvent titration method is less susceptible to false positives in identifying the imprinting effect. Second, the method is able to differentiate and quantify changes in binding capacity, as measured at a fixed guest and polymer concentration, arising from templation or monomer aggregation processes in the prepolymerization solution. Third, the method was also easy to carry out, taking advantage of the ease of preparing MIPs.


Assuntos
Impressão Molecular , Polímeros/química , Solventes/química , Adsorção , Soluções/química , Titulometria
12.
J Colloid Interface Sci ; 676: 701-714, 2024 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-39059277

RESUMO

Clear aligners undergo rapid stress relaxation in warm, moist oral environments, compromising therapeutic effectiveness and longevity of treatment. To develop an innovative multilayer composite material with improved stability and reduced stress release, we have engineered an innovative coating characterized by the surface aggregation of polydimethylsiloxane (PDMS), which imparts a pronounced hydrophobic effect. In addition, the chemically and physically cross-linked structure of the coating reduces the free volume created by molecular chain rearrangement owing to the presence of water molecules, thereby minimizing water penetration into the coating. Concurrently, the coating's internal structure is enriched with numerous polar functional groups to capture water molecules that penetrate into the inside of the coating. Through combination of these mechanisms, water molecules are effectively sequestered, thereby impeding their penetration into the polyethylene terephthalate glycol (PETG) substrate. The impact of the polydimethylsiloxane content on the triple-action water-resistance mechanisms was thoroughly examined using attenuated total reflection (ATR)-Fourier transform infrared (FTIR), water absorption rate, water swelling rate, and X-ray photoelectron spectroscopy. The low surface energy cross-linked polyurethane coating is applied to the polyethylene terephthalate glycol (PETG) substrate to create a novel composite material with specific mechanical properties and reduced stress relaxation. The composite material remains stable in simulated oral environment with linear swelling rate of 0.58 % upon water absorption. Additionally, the stress release rate of the composite material within 336 h is notably lower (23.64 %) than that of PETG (62.29 %).

13.
Nanomaterials (Basel) ; 14(1)2024 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-38202557

RESUMO

Ammonia (NH3) is vital in modern agriculture and industry as a potential energy carrier. The electrocatalytic reduction of nitrate (NO3-) to ammonia under ambient conditions offers a sustainable alternative to the energy-intensive Haber-Bosch process. However, achieving high selectivity in this conversion poses significant challenges due to the multi-step electron and proton transfer processes and the low proton adsorption capacity of transition metal electrocatalysts. Herein, we introduce a novel approach by employing functionalized multi-walled carbon nanotubes (MWCNTs) as carriers for active cobalt catalysts. The exceptional conductivity of MWCNTs significantly reduces charge transfer resistance. Their unique hollow structure increases the electrochemical active surface area of the electrocatalyst. Additionally, the one-dimensional hollow tube structure and graphite-like layers within MWCNTs enhance adsorption properties, thus mitigating the diffusion of intermediate and stabilizing active cobalt species during nitrate reduction reaction (NitRR). Using the MWCNT-supported cobalt catalyst, we achieved a notable NH3 yield rate of 4.03 mg h-1 cm-2 and a high Faradaic efficiency of 84.72% in 0.1 M KOH with 0.1 M NO3-. This study demonstrates the potential of MWCNTs as advanced carriers in constructing electrocatalysts for efficient nitrate reduction.

14.
RSC Adv ; 14(11): 7499-7506, 2024 Feb 29.
Artigo em Inglês | MEDLINE | ID: mdl-38440268

RESUMO

The difference of NH3 oxidation mechanism over SAPO-34 and Cu-SAPO-34 was studied. XRD (X-ray diffraction), SEM (scanning electron microscopy) and H2-TPR (H2-temperature programmed desorption) were conducted to estimate the Cu species distribution. The quantity of individual Cu2+ ions escalated with the elevation of silicon content in the Cu/SAPO-34 catalysts, leading to an enhancement in the activity of the NH3-SCR (ammonia-selective catalytic reduction) process. This augmentation in activity can be attributed to the increased presence of isolated Cu2+ species, which are pivotal in facilitating the catalytic reaction. In addition, the kinetic test of NH3 oxidation indicated that the CuO species were the active sites for NH3 oxidation. Specifically, the strong structural Brønsted acid sites were the NH3 oxidation active sites over the SAPO-34 support, and the NH3 reacted with the O2 on the Brønsted acid sites to produce the NO mainly. While the NH3 oxidation mechanism over Cu/SAPO-34 consisted of two steps: firstly, NH3 reacted with O2 on CuO sites or residual Brønsted acid sites to form NO as the product; subsequently, the generated NO was reduced by NH3 into N2 on isolated Cu2+ sites. Simultaneously, the isolated Cu2+ sites might demonstrate a significant function in the NH3 oxidation process to form N2. The identification of active sites and corresponding mechanism could deepen the understanding of excellent performance of NH3-SCR over the Cu/SAPO-34 catalyst at high temperature.

15.
Adv Sci (Weinh) ; 11(23): e2401889, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38554399

RESUMO

All-solid-state batteries (ASSBs) based on inorganic solid electrolytes fascinate a large body of researchers in terms of overcoming the inferior energy density and safety issues of existing lithium-ion batteries. To date, the cathode designs in the ASSBs achieve remarkable achievements, adding the urgency of scaling up the battery system toward inorganic solid-state pouch cell configuration for the application market. Herein, the recent developments of cathode materials and the design considerations for their application in the pouch cell format are reviewed to straighten out the roadmap of ASSBs. Specifically, the intercalation compounds and the conversion materials with conversion chemistries are highlighted and discussed as two potentially valuable material types. This review focuses on the basic electrochemical mechanisms, mechanical contact issues, and sheet-type structure in inorganic solid-state pouch cells with corresponding perspectives, thus guiding the future research direction. Finally, the benchmarks for manufacturing inorganic solid-state pouch cells to meet practical high energy density targets are provided in this review for the development of commercially viable products.

16.
Nanomicro Lett ; 16(1): 275, 2024 Aug 22.
Artigo em Inglês | MEDLINE | ID: mdl-39168930

RESUMO

Electrocatalytic 5-hydroxymethylfurfural oxidation reaction (HMFOR) provides a promising strategy to convert biomass derivative to high-value-added chemicals. Herein, a cascade strategy is proposed to construct Pd-NiCo2O4 electrocatalyst by Pd loading on Ni-doped Co3O4 and for highly active and stable synergistic HMF oxidation. An elevated current density of 800 mA cm-2 can be achieved at 1.5 V, and both Faradaic efficiency and yield of 2,5-furandicarboxylic acid remained close to 100% over 10 consecutive electrolysis. Experimental and theoretical results unveil that the introduction of Pd atoms can modulate the local electronic structure of Ni/Co, which not only balances the competitive adsorption of HMF and OH- species, but also promote the active Ni3+ species formation, inducing high indirect oxidation activity. We have also discovered that Ni incorporation facilitates the Co2+ pre-oxidation and electrophilic OH* generation to contribute direct oxidation process. This work provides a new approach to design advanced electrocatalyst for biomass upgrading.

17.
Nanomicro Lett ; 15(1): 166, 2023 Jul 03.
Artigo em Inglês | MEDLINE | ID: mdl-37394676

RESUMO

Molybdenum carbide (Mo2C) materials are promising electrocatalysts with potential applications in hydrogen evolution reaction (HER) due to low cost and Pt-like electronic structures. Nevertheless, their HER activity is usually hindered by the strong hydrogen binding energy. Moreover, the lack of water-cleaving sites makes it difficult for the catalysts to work in alkaline solutions. Here, we designed and synthesized a B and N dual-doped carbon layer that encapsulated on Mo2C nanocrystals (Mo2C@BNC) for accelerating HER under alkaline condition. The electronic interactions between the Mo2C nanocrystals and the multiple-doped carbon layer endow a near-zero H adsorption Gibbs free energy on the defective C atoms over the carbon shell. Meanwhile, the introduced B atoms afford optimal H2O adsorption sites for the water-cleaving step. Accordingly, the dual-doped Mo2C catalyst with synergistic effect of non-metal sites delivers superior HER performances of a low overpotential (99 mV@10 mA cm-2) and a small Tafel slope (58.1 mV dec-1) in 1 M KOH solution. Furthermore, it presents a remarkable activity that outperforming the commercial 10% Pt/C catalyst at large current density, demonstrating its applicability in industrial water splitting. This study provides a reasonable design strategy towards noble-metal-free HER catalysts with high activity.

18.
Polymers (Basel) ; 15(22)2023 Nov 20.
Artigo em Inglês | MEDLINE | ID: mdl-38006188

RESUMO

Novel core-shell magnetic molecularly imprinted polymers (MMIPs) were synthesized using the sol-gel method for the adsorption of cefixime (CFX). Fe3O4@SiO2 is the core, and molecularly imprinted polymers (MIPs) are the shell, which can selectively interact with CFX. The preparation conditions, adsorption kinetics, adsorption isotherms, selective adsorption ability, and reutilization performance of the MMIPs were investigated. The adsorption capacity of MMIPs for CFX was 111.38 mg/g, which was about 3.5 times that of MNIPs. The adsorption equilibrium time was 180 min. The dynamic adsorption experiments showed that the adsorption process of MMIPs to CFX conformed to the pseudo-second-order model. Through static adsorption study, the Scatchard analysis showed that MMIPs had two types of binding sites-the high-affinity binding sites and the low-affinity binding sites-while the Langmuir model fit the adsorption isotherms well (R2 = 0.9962). Cefepime and ceftiofur were selected as the structural analogs of CFX for selective adsorption studies; the adsorption of CFX by MMIPs was higher than that of other structural analogs; and the imprinting factors of CFX, cefepime, and ceftiofur were 3.5, 1.7, and 1.4, respectively. Furthermore, the MMIPs also showed excellent reusable performance.

19.
Dalton Trans ; 53(1): 162-170, 2023 Dec 19.
Artigo em Inglês | MEDLINE | ID: mdl-38018516

RESUMO

The energy-intensive processes for the industrial production of ammonia necessitates the development of new methods to be proposed that will aid in reducing the global energy consumption. Specifically, the electrocatalytic nitrate reduction reaction (NO3RR) to produce ammonia is more thermodynamically feasible than the electrocatalytic nitrogen reduction reaction (NRR). However, it is hindered by a low catalytic activity due to its complex reaction pathways. Herein, we synthesized a novel electrocatalyst, RuOx-Co3O4 nanoparticles, with abundant interfaces, which exhibited an enhanced catalytic activity for efficient ammonia synthesis. This catalyst delivered a partial current density of 65.8 mA cm-2 for NH3 production, a faradaic efficiency (FE) of 89.7%, and a superior ammonia yield rate of up to 210.5 µmol h-1 cm-2 at -0.6 V vs. RHE. X-ray photoelectron and Raman spectroscopy revealed that the formed interfacial Ru-O-Co bond can decorate the electronic structures of the active sites and accelerate the absorption of NO3-, thus promoting the production of ammonia.

20.
Nanoscale ; 15(44): 17793-17807, 2023 Nov 16.
Artigo em Inglês | MEDLINE | ID: mdl-37916998

RESUMO

Superhydrophobic surfaces have attracted broad attention because of their unique water repellency but are restricted by poor wear resistance, weak adhesion to the substrate, and complex fabrication processes. Herein, a double-layer coating strategy consisting of the amino fluorine-silicone resin/epoxy resin (AFSR/EP) system is created. The system features a high hardness and transparent hydrophobic interface adhesive layer through the amine-epoxy "click" chemical reaction. The environmentally friendly resin system and low-cost nano-silica particles (n-SiO2) are composited and sprayed onto the substrate surface to form a superhydrophobic layer with outstanding robustness and excellent environmental stability. The prepared AFSR/EP@n-SiO2 composite coatings have a water contact angle of 161.1° and a sliding angle of 3.4°, demonstrating high superhydrophobic properties. Benefitting from the complementary advantages of silicone/epoxy resin, the prepared composite coatings maintain remarkable water repellency after various harsh environmental tests, including cyclic mechanical abrasion and tape-stripping, acid-base (pH 1 and pH 14) treatment, 10 wt% NaCl (pH 7) salt solution immersion, temperature treatment, knife scratching, and long-term ultraviolet radiation treatment, showing reinforced mechanical robustness and durable anti-corrosion stability. Notably, surface hardness of 5H and optical transparency over 80% can be achieved. The simple method offers a novel approach for the large-scale preparation of multifunctional superhydrophobic coatings.

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