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1.
Molecules ; 29(12)2024 Jun 11.
Artigo em Inglês | MEDLINE | ID: mdl-38930847

RESUMO

Electrochemical nitrate reduction (NO3-RR) has been recognized as a promising strategy for sustainable ammonia (NH3) production due to its environmental friendliness and economical nature. However, the NO3-RR reaction involves an eight-electron coupled proton transfer process with many by-products and low Faraday efficiency. In this work, a molybdenum oxide (MoOx)-decorated titanium dioxide nanotube on Ti foil (Mo/TiO2) was prepared by means of an electrodeposition and calcination process. The structure of MoOx can be controlled by regulating the concentration of molybdate during the electrodeposition process, which can further influence the electron transfer from Ti to Mo atoms, and enhance the binding energy of intermediate species in NO3-RR. The optimized Mo/TiO2-M with more Mo(IV) sites exhibited a better activity for NO3-RR. The Mo/TiO2-M electrode delivered a NH3 yield of 5.18 mg h-1 cm-2 at -1.7 V vs. Ag/AgCl, and exhibited a Faraday efficiency of 88.05% at -1.4 V vs. Ag/AgCl. In addition, the cycling test demonstrated that the Mo/TiO2-M electrode possessed a good stability. This work not only provides an attractive electrode material, but also offers new insights into the rational design of catalysts for NO3-RR.

2.
Int J Mol Sci ; 24(18)2023 Sep 14.
Artigo em Inglês | MEDLINE | ID: mdl-37762387

RESUMO

The pursuit of superhydrophilic materials with hierarchical structures has garnered significant attention across diverse application domains. In this study, we have successfully crafted Ni-Mn LDHs@CuC2O4 nanosheet arrays on a copper mesh (CM) through a synergistic process involving chemical oxidation and hydrothermal deposition. Initially, CuC2O4 nanosheets were synthesized on the copper mesh, closely followed by the growth of Ni-Mn LDHs nanosheets, culminating in the establishment of a multi-tiered surface architecture with exceptional superhydrophilicity and remarkable underwater superoleophobicity. The resultant Ni-Mn LDHs@CuC2O4 CM membrane showcased an unparalleled amalgamation of traits, including superhydrophilicity, underwater superoleophobicity, and the ability to harness photocatalytic forces for self-cleaning actions, making it an advanced oil-water separation membrane. The membrane's performance was impressive, manifesting in a remarkable water flux range (70 kL·m-2·h-1) and an efficient oil separation capability for both oil/water mixture and surfactant-stabilized emulsions (below 60 ppm). Moreover, the innate superhydrophilic characteristics of the membrane rendered it a prime candidate for deployment as a supercapacitor cathode material. Evidenced by a capacitance of 5080 mF·cm-2 at a current density of 6 mA cm-2 in a 6 M KOH electrolyte, the membrane's potential extended beyond oil-water separation. This work not only introduces a cutting-edge oil-water separation membrane and supercapacitor electrode but also offers a promising blueprint for the deliberate engineering of hierarchical structure arrays to cater to a spectrum of related applications.


Assuntos
Cobre , Surfactantes Pulmonares , Capacitância Elétrica , Eletrodos , Fenótipo
3.
Int J Mol Sci ; 24(6)2023 Mar 07.
Artigo em Inglês | MEDLINE | ID: mdl-36982143

RESUMO

A large amount of cyanide-containing wastewater is discharged during electrode material synthesis. Among them, cyanides will form metal-cyanide complex ions which possess high stability, making it challenging to separate them from these wastewaters. Therefore, it is imperative to understand the complexation mechanism of cyanide ions and heavy metal ions from wastewater in order to obtain a deep insight into the process of cyanide removal. This study employs Density Functional Theory (DFT) calculations to reveal the complexation mechanism of metal-cyanide complex ions formed by the interaction of Cu+ and CN- in copper cyanide systems and its transformation patterns. Quantum chemical calculations show that the precipitation properties of Cu(CN)43- can assist in the removal of CN-. Therefore, transferring other metal-cyanide complex ions to Cu(CN)43- can achieve deep removal. OLI studio 11.0 analyzed the optimal process parameters of Cu(CN)43- under different conditions and determined the optimal process parameters of the removal depth of CN-. This work has the potential to contribute to the future preparation of related materials such as CN- removal adsorbents and catalysts and provide theoretical foundations for the development of more efficient, stable, and environmentally friendly next-generation energy storage electrode materials.


Assuntos
Complexos de Coordenação , Poluentes Químicos da Água , Águas Residuárias , Cobre/química , Cianetos/química , Água , Especificidade da Espécie , Íons , Poluentes Químicos da Água/química
4.
Molecules ; 28(1)2023 Jan 03.
Artigo em Inglês | MEDLINE | ID: mdl-36615623

RESUMO

It is highly attractive to design pseudocapacitive metal oxides as anodes for supercapacitors (SCs). However, as they have poor conductivity and lack active sites, they generally exhibit an unsatisfied capacitance under high current density. Herein, polypyrrole-coated low-crystallinity Fe2O3 supported on carbon cloth (D-Fe2O3@PPy/CC) was prepared by chemical reduction and electrodeposition methods. The low-crystallinity Fe2O3 nanorod achieved using a NaBH4 treatment offered more active sites and enhanced the Faradaic reaction in surface or near-surface regions. The construction of a PPy layer gave more charge storage at the Fe2O3/PPy interface, favoring the limitation of the volume effect derived from Na+ transfer in the bulk phase. Consequently, D-Fe2O3@PPy/CC displayed enhanced capacitance and stability. In 1 M Na2SO4, it showed a specific capacitance of 615 mF cm-2 (640 F g-1) at 1 mA cm-2 and still retained 79.3% of its initial capacitance at 10 mA cm-2 after 5000 cycles. The design of low-crystallinity metal oxides and polymer nanocomposites is expected to be widely applicable for the development of state-of-the-art electrodes, thus opening new avenues for energy storage.

5.
Molecules ; 28(12)2023 Jun 08.
Artigo em Inglês | MEDLINE | ID: mdl-37375187

RESUMO

Developing advanced carbon materials by utilizing biomass waste has attracted much attention. However, porous carbon electrodes based on the electronic-double-layer-capacitor (EDLC) charge storage mechanism generally presents unsatisfactory capacitance and energy density. Herein, an N-doped carbon material (RSM-0.33-550) was prepared by directly pyrolyzing reed straw and melamine. The micro- and meso-porous structure and the rich active nitrogen functional group offered more ion transfer and faradaic capacitance. X-ray diffraction (XRD), Raman, scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), Brunauer-Emmett-Teller (BET) measurements were used to characterize the biomass-derived carbon materials. The prepared RSM-0.33-550 possessed an N content of 6.02% and a specific surface area of 547.1 m2 g-1. Compared with the RSM-0-550 without melamine addition, the RSM-0.33-550 possessed a higher content of active nitrogen (pyridinic-N) in the carbon network, thus presenting an increased number of active sites for charge storage. As the anode for supercapacitors (SCs) in 6 M KOH, RSM-0.33-550 exhibited a capacitance of 202.8 F g-1 at a current density of 1 A g-1. At a higher current density of 20 A g-1, it still retained a capacitance of 158 F g-1. Notably, it delivered excellent stability with capacity retention of 96.3% at 20 A g-1 after 5000 cycles. This work not only offers a new electrode material for SCs, but also gives a new insight into rationally utilizing biomass waste for energy storage.

6.
Molecules ; 27(1)2022 Jan 02.
Artigo em Inglês | MEDLINE | ID: mdl-35011500

RESUMO

Developing an ideal and cheap adsorbent for adsorbing heavy metals from aqueous solution has been urgently need. In this study, a novel, effective and low-cost method was developed to prepare the biochar from lettuce waste with H3PO4 as an acidic activation agent at a low-temperature (circa 200 °C) hydrothermal carbonization process. A batch adsorption experiment demonstrated that the biochar reaches the adsorption equilibrium within 30 min, and the optimal adsorption capacity of Cd(II) is 195.8 mg∙g-1 at solution pH 6.0, which is significantly improved from circa 20.5 mg∙g-1 of the original biochar without activator. The fitting results of the prepared biochar adsorption data conform to the pseudo-second-order kinetic model (PSO) and the Sips isotherm model, and the Cd(II) adsorption is a spontaneous and exothermic process. The hypothetical adsorption mechanism is mainly composed of ion exchange, electrostatic attraction, and surface complexation. This work offers a novel and low-temperature strategy to produce cheap and promising carbon-based adsorbents from organic vegetation wastes for removing heavy metals in aquatic environment efficiently.


Assuntos
Cádmio/química , Carvão Vegetal/química , Lactuca/química , Poluentes Químicos da Água/química , Purificação da Água , Ácidos Fosfóricos/química
7.
Chemistry ; 27(29): 7908-7914, 2021 May 20.
Artigo em Inglês | MEDLINE | ID: mdl-33778989

RESUMO

It is highly desirable to design advanced heteroatomic doped porous carbon for wide application. Herein, N-doped porous carbon (NPC) was developed via the fabrication of high nitrogen cross-linked triazine polymers followed by pyrolysis and activation with controllable porous structure. The as-synthesized NPC at the pyrolysis temperature of 700 °C possessed rich nitrogen content (up to 11.51 %) and high specific surface area (1353 m2 g-1 ), which led to a high CO2 adsorption capability at 5.67 mmol g-1 at 298.15 K and 5 bar pressure and excellent stability. When the activation temperature was at 600 °C, such NPC exhibited a superior electrochemical performance as anode for supercapacitors with a specific capacitance of 158.8 and 113 F g-1 in 6 M KOH at a current density of 1 and 10 A g-1 , respectively. Notably, it delivered an excellent stability with capacity retention of 97.4 % at 20 A g-1 after 6000 cycles.

8.
Molecules ; 26(17)2021 Aug 31.
Artigo em Inglês | MEDLINE | ID: mdl-34500736

RESUMO

CO2 adsorption in porous carbon materials has attracted great interests for alleviating emission of post-combustion CO2. In this work, a novel nitrogen-doped porous carbon material was fabricated by carbonizing the precursor of melamine-resorcinol-formaldehyde resin/graphene oxide (MR/GO) composites with KOH as the activation agent. Detailed characterization results revealed that the fabricated MR(0.25)/GO-500 porous carbon (0.25 represented the amount of GO added in wt.% and 500 denoted activation temperature in °C) had well-defined pore size distribution, high specific surface area (1264 m2·g-1) and high nitrogen content (6.92 wt.%), which was mainly composed of the pyridinic-N and pyrrolic-N species. Batch adsorption experiments demonstrated that the fabricated MR(0.25)/GO-500 porous carbon delivered excellent CO2 adsorption ability of 5.21 mmol·g-1 at 298.15 K and 500 kPa, and such porous carbon also exhibited fast adsorption kinetics, high selectivity of CO2/N2 and good recyclability. With the inherent microstructure features of high surface area and abundant N adsorption sites species, the MR/GO-derived porous carbon materials offer a potentially promising adsorbent for practical CO2 capture.

9.
Molecules ; 26(11)2021 Jun 07.
Artigo em Inglês | MEDLINE | ID: mdl-34200132

RESUMO

Designing of porous carbon system for CO2 uptake has attracted a plenty of interest due to the ever-increasing concerns about climate change and global warming. Herein, a novel N rich porous carbon is prepared by in-situ chemical oxidation polyaniline (PANI) on a surface of multi-walled carbon nanotubes (MWCNTs), and then activated with KOH. The porosity of such carbon materials can be tuned by rational introduction of MWCNTs, adjusting the amount of KOH, and controlling the pyrolysis temperature. The obtained M/P-0.1-600-2 adsorbent possesses a high surface area of 1017 m2 g-1 and a high N content of 3.11 at%. Such M/P-0.1-600-2 adsorbent delivers an enhanced CO2 capture capability of 2.63 mmol g-1 at 298.15 K and five bars, which is 14 times higher than that of pristine MWCNTs (0.18 mmol g-1). In addition, such M/P-0.1-600-2 adsorbent performs with a good stability, with almost no decay in a successive five adsorption-desorption cycles.

10.
J Mater Sci Mater Med ; 27(3): 45, 2016 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-26758892

RESUMO

Although polyvinylidene fluoride (PVDF) is non-toxic and stable in vivo, its hydrophobic surface has limited its bio-applications due to poor cell-material interaction and thrombus formation when used in blood contacting devices. In this study, surface modification of PVDF using naturally derived non-mammalian collagen was accomplished via direct surface-initiated atom transfer radical polymerisation (SI-ATRP) to enhance its cytocompatibility and hemocompatibility. Results showed that Type I collagen was successfully extracted from fish scales and bullfrog skin. The covalent immobilisation of fish scale-derived collagen (FSCOL) and bullfrog skin-derived collagen (BFCOL) onto the PVDF surface improves the attachment and proliferation of human umbilical vein endothelial cells (HUVECs). Furthermore, both FSCOL and BFCOL had comparable anti-thrombogenic profiles to that of commercially available bovine collagen (BVCOL). Also, cell surface expression of the leukocyte adhesion molecule was lower on HUVECs cultured on non-mammalian collagen surfaces than on BVCOL, which is an indication of lower pro-inflammatory response. Overall, results from this study demonstrated that non-mammalian sources of collagen could be used to confer bioactivity to PVDF, with comparable cell-material interactions and hemocompatibility to BVCOL. Additionally, higher expression levels of Type IV collagen in HUVECs cultured on FSCOL and BFCOL were observed as compared to BVCOL, which is an indication that the non-mammalian sources of collagen led to a better pro-angiogenic properties, thus making them suitable for blood contacting applications.


Assuntos
Colágeno , Células Endoteliais/fisiologia , Polivinil/química , Animais , Plaquetas/efeitos dos fármacos , Configuração de Carboidratos , Bovinos , Células Cultivadas , Peixes , Regulação da Expressão Gênica , Humanos , Molécula 1 de Adesão Intercelular/genética , Molécula 1 de Adesão Intercelular/metabolismo , Ativação Plaquetária/efeitos dos fármacos , RNA/genética , RNA/metabolismo , Rana catesbeiana , Propriedades de Superfície , Molécula 1 de Adesão de Célula Vascular/genética , Molécula 1 de Adesão de Célula Vascular/metabolismo
11.
Langmuir ; 30(48): 14498-511, 2014 Dec 09.
Artigo em Inglês | MEDLINE | ID: mdl-25419845

RESUMO

Utilization of nanotechnologies in condensation has been recognized as one opportunity to improve the efficiency of large-scale thermal power and desalination systems. High-performance and stable dropwise condensation in widely-used copper heat exchangers is appealing for energy and water industries. In this work, a scalable and low-cost nanofabrication approach was developed to fabricate superhydrophobic copper oxide (CuO) nanoneedle surfaces to promote dropwise condensation and even jumping-droplet condensation. By conducting systematic surface characterization and in situ environmental scanning electron microscope (ESEM) condensation experiments, we were able to probe the microscopic formation physics of droplets on irregular nanostructured surfaces. At the early stages of condensation process, the interfacial surface tensions at the edge of CuO nanoneedles were found to influence both the local energy barriers for microdroplet growth and the advancing contact angles when droplets undergo depinning. Local surface roughness also has a significant impact on the volume of the condensate within the nanostructures and overall heat transfer from the vapor to substrate. Both our theoretical analysis and in situ ESEM experiments have revealed that the liquid condensate within the nanostructures determines the amount of the work of adhesion and kinetic energy associated with droplet coalescence and jumping. Local and global droplet growth models were also proposed to predict how the microdroplet morphology within nanostructures affects the heat transfer performance of early-stage condensation. Our quantitative analysis of microdroplet formation and growth within irregular nanostructures provides the insight to guide the anodization-based nanofabrication for enhancing dropwise and jumping-droplet condensation performance.

12.
Int J Biol Macromol ; 269(Pt 1): 132078, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38705332

RESUMO

The remarkable characteristics of porous biochar have generated significant interest in various fields, such as CO2 capture and supercapacitors. The modification of aerogel-derived porous biochar through activation and heteroatomic doping can effectively enhance CO2 adsorption and improve supercapacitor performance. In this study, a novel N, B-co-doped porous biochar (NBCPB) was synthesized by carbonating and activating the N, B dual-doped cellulose aerogel. N and B atoms were doped in-situ using a modified alkali-urea method. The potassium citrate was served as both an activator and a salt template to facilitate the formation of a well-developed nanostructure. The optimized NBCPB-650-1 (where 650 corresponded to activation temperature and 1 represented mass ratio of potassium citrate activator to carbonized NBCPB-400 precursor) displayed the largest micropore volume of 0.40 cm3·g-1 and a high specific surface area of 891 m2·g-1, which contributed to an excellent CO2 adsorption capacity of 4.19 mmol·g-1 at 100 kPa and 25 °C, a high CO2/N2 selectivity, and exceptional reusability (retained >97.5 % after 10 adsorption-desorption cycles). Additionally, the NBCPB-650-1 electrode also delivered a high capacitance of 220.9 F·g-1 at 1 A·g-1. Notably, the symmetrical NBCPB-650-1 supercapacitor exhibited a high energy density of 9 Wh·kg-1 at the power density of 100 W·kg-1. This study not only presents the potential application of NBCPB-650-1 material in CO2 capture and electrochemical energy storage, but also offers a new insight into easy-to-scale production of heteroatomic-modified porous biochar.


Assuntos
Dióxido de Carbono , Celulose , Carvão Vegetal , Capacitância Elétrica , Nitrogênio , Dióxido de Carbono/química , Carvão Vegetal/química , Porosidade , Celulose/química , Adsorção , Nitrogênio/química , Géis/química , Eletrodos
13.
Nanoscale ; 15(39): 16219-16226, 2023 Oct 12.
Artigo em Inglês | MEDLINE | ID: mdl-37781913

RESUMO

The electrocatalytic nitrogen reduction reaction (eNRR) has been widely recognized as a promising method for green ammonia synthesis. However, the inert NN bond, inferior catalytic activity and small electrochemically active area impede its practical application. To circumvent these problems, we proposed self-supported Ti-doped iron phosphide (FeP) nanorod arrays grown on carbon cloth (Ti-FeP/CC) as an electrode for eNRR. The introduction of Ti doping sites regulated the electron structure of FeP, leading to electron migration from Fe to P, which facilitated N2-to-NH3 conversion. The as-prepared Ti-FeP/CC showed an enhancement of electrochemical surface area (ECSA), high electrical conductivity and well-exposed active sites. Ti-FeP/CC was capable of producing a high NH3 yield of 10.93 µg h-1 cm-2 and faradaic efficiency of 10.77% at an optimal voltage of -0.3 V (vs. RHE) in a 0.1 M Na2SO4 solution with excellent stability and durability during the eNRR process. This work not only presents a promising electrode material for eNRR, but also provides a new insight into rational heteroatom doping for electrocatalysis.

14.
ACS Appl Mater Interfaces ; 15(51): 59413-59421, 2023 Dec 27.
Artigo em Inglês | MEDLINE | ID: mdl-38102077

RESUMO

Multiple oxidation-state metal oxide has presented a promising charge storage capability for aqueous supercapacitors (SCs); however, the ion insert/deinsert behavior in the bulk phase generally gives a sluggish reaction kinetic and considerable volume effect. Herein, iron oxide/poly(3,4-ethylenedioxythiophene) (Fe2O3/PEDOT) heterointerface was constructed and enabled boosted Faradaic pseudocapacitance by dual-ion-involved redox reactions in Na2SO3 electrolytes. The Fe2O3/PEDOT interface served as a "bridge" to couple electrode and anion SO32- and exhibited a strong force and stable bonding with SO32-, thus providing an additional Faradaic charge storage contribution for SCs. Significantly, the PEDOT-capsulated Fe2O3 nanorod array (Fe2O3@PEDOT) electrode presented a specific capacitance of 338 mF cm-2 at 1 mA cm-2 with 1 M Na2SO3 electrolyte, which was twice that of the pristine Fe2O3 nanorod electrode. The boosted interfaced Faradaic reaction of SO32- partially hindered the intercalation of Na+ in the Fe2O3 bulk phase, efficiently favoring the electrochemical stability.

15.
J Hazard Mater ; 451: 131142, 2023 Jun 05.
Artigo em Inglês | MEDLINE | ID: mdl-36893603

RESUMO

It is highly attractive to develop highly efficient oil-in-water (O/W) emulsion separation technologies for promoting the oily wastewater treatment. Herein, a novel inversely Stenocara beetle-like hierarchical structure of superhydrophobic SiO2 nanoparticle-decorated CuC2O4 nanosheet arrays were prepared on copper mesh membrane by bridging polydopamine (PDA) to make a SiO2/PDA@CuC2O4 membrane for substantially enhanced separation of O/W emulsions. The superhydrophobic SiO2 particles on the as-prepared SiO2/PDA@CuC2O4 membranes were served as localized active sites to induce coalescence of small-size oil droplets in oil-in-water (O/W) emulsions. Such innovated membrane delivered outstanding demulsification ability of O/W emulsion with a high separation flux of 2.5 kL⋅m-2⋅h-1 and its filtrate's chemical oxygen demand (COD) being 30 and 100 mg⋅L-1 for surfactant-free emulsion (SFE) and surfactant-stabilized emulsion (SSE), respectively, and also exhibited a good anti-fouling performance in cycling tests. The innovative design strategy developed in this work broadens the application of superwetting materials for oil-water separation and presents a promising prospect in practical oily wastewater treatment applications.

16.
J Hazard Mater ; 430: 128449, 2022 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-35176698

RESUMO

Dealing with arsenic pollution has been of great concern owing to inherent toxicity of As(III) to environments and human health. Herein, a novel multilayered SnO2/PPy/ß-PbO2 structure on TiO2 nanotube arrays (TNAs/SnO2/PPy/ß-PbO2) was synthesized by a multi-step electrodeposition process as an efficient electrocatalyst for As(III) oxidation in aqueous solution. Such TNAs/SnO2/PPy/ß-PbO2 electrode exhibited a higher charge transfer, tolerable stability, and high oxygen evolution potential (OEP). The intriguing structure with a SnO2, PPy, and ß-PbO2 active layers provided a larger electrochemical active area for electrocatalytic As(III) oxidation. The as-synthesized TNAs/SnO2/PPy/ß-PbO2 anode achieved drastically enhanced As(Ⅲ) conversion efficiency of 90.72% compared to that of TNAs/ß-PbO2 at circa 45.4%. The active species involved in the electrocatalytic oxidation process included superoxide radical (•O2-), sulfuric acid root radicals (•SO4-), and hydroxyl radicals (•OH). This work offers a new strategy to construct a high-efficiency electrode to meet the requirements of favorable electrocatalytic oxidation properties, good stability, and high electrocatalytic activity for As(III) transformation to As(V).


Assuntos
Óxidos , Poluentes Químicos da Água , Eletrodos , Humanos , Oxirredução , Óxidos/química , Titânio/química , Poluentes Químicos da Água/química
17.
Sci Rep ; 12(1): 8178, 2022 05 17.
Artigo em Inglês | MEDLINE | ID: mdl-35581265

RESUMO

Membrane-on-chip is of growing interest in a wide variety of high-throughput environmental and water research. Advances in membrane technology continuously provide novel materials and multi-functional structures. Yet, the incorporation of membrane into microfluidic devices remains challenging, thus limiting its versatile utilization. Herein, via micro-stereolithography 3D printing, we propose and fabricate a "fish gill" structure-integrated on-chip membrane device, which has the self-sealing attribute at structure-membrane interface without extra assembling. As a demonstration, metallic micromesh and polymeric membrane can also be easily embedded in 3D printed on-chip device to achieve anti-fouling and anti-clogging functionality for wastewater filtration. As evidenced from in-situ visualization of structure-fluid-foulant interactions during filtration process, the proposed approach successfully adopts the fish feeding mechanism, being able to "ricochet" foulant particles or droplets through hydrodynamic manipulation. When benchmarked with two common wastewater treatment scenarios, such as plastic micro-particles and emulsified oil droplets, our biomimetic filtration devices exhibit 2 ~ 3 times longer durability for high-flux filtration than devices with commercial membrane. This proposed 3D printing-on-membrane approach, elegantly bridging the fields of microfluidics and membrane science, is instrumental to many other applications in energy, sensing, analytical chemistry and biomedical engineering.


Assuntos
Biomimética , Estereolitografia , Dispositivos Lab-On-A-Chip , Microfluídica , Impressão Tridimensional
18.
J Hazard Mater ; 426: 127793, 2022 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-34839976

RESUMO

Single-atom noble metal catalysts have been widely studied for catalytic oxidation of CO. Regulating the coordination environment of single metal atom site is an effective strategy to improve the intrinsic catalytic activity of single atom catalyst. In this work, single atom Pd catalyst supported on Pr-doped CeO2 nanorods was prepared, and the performance and nature of Pr-coordinated atomic Pd site in CO catalytic oxidation are systematically investigated. The structure characterization using AC-HAADF-STEM, EXAFS, XRD and Raman spectroscopy demonstrate the formation of single atom Pd site and abundant surface oxygen vacancies on the surface of Pr-doped CeO2 nanorod. With the combination of the XPS characterization and DFT calculations, the oxidation state of Pd on Pr-doped CeO2 nanorod is determined lower than that on CeO2 nanorod. The turnover frequency of CO oxidation is markedly increased from 8.4 × 10-3 to 31.9 × 10-3 s with Pr-doping at 130 ºC and GHSV of 70,000 h-1. Combined with kinetic studies, DRIFT and DFT calculations, the doped-Pr atoms reduced the formation energy of oxygen vacancies and generate more oxygen vacancies around the atomically dispersed Pd sites on the surface of cerium oxide, which reduces the dissociation energy of oxygen, thereby accelerating the reaction rate of CO oxidation.

19.
Langmuir ; 27(6): 2761-74, 2011 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-21338094

RESUMO

An environmentally benign approach to impart stainless steel (SS) surfaces with antifouling and antibacterial functionalities was described. Surface-initiated atom transfer radical polymerization (ATRP) of poly(ethylene glycol) monomethacrylate) (PEGMA) from the SS surface-coupled catecholic L-3,4-dihydroxyphenylalanine (DOPA) with terminal alkyl halide initiator was first carried out, followed by the immobilization of lysozyme at the chain ends of poly(ethylene glycol) branches of the grafted PEGMA polymer brushes. The functionalized SS surfaces were shown to be effective in preventing bovine serum albumin (BSA) adsorption and in reducing bacterial adhesion and biofilm formation. The surfaces also exhibited good bactericidal effects against Escherichia coli and Staphylococcus aureus. The concomitant incorporation of antifouling hydrophilic brushes and antibacterial enzymes or peptides onto metal surfaces via catecholic anchors should be readily adaptable to other metal substrates, and is potentially useful for biomedical and biomaterial applications.


Assuntos
Antibacterianos/farmacologia , Escherichia coli/efeitos dos fármacos , Metacrilatos/farmacologia , Muramidase/química , Polietilenoglicóis/farmacologia , Aço Inoxidável/farmacologia , Staphylococcus aureus/efeitos dos fármacos , Adsorção , Animais , Antibacterianos/química , Incrustação Biológica/prevenção & controle , Bovinos , Relação Dose-Resposta a Droga , Metacrilatos/química , Testes de Sensibilidade Microbiana , Estrutura Molecular , Muramidase/metabolismo , Tamanho da Partícula , Polietilenoglicóis/química , Ácidos Polimetacrílicos , Soroalbumina Bovina/química , Aço Inoxidável/química , Relação Estrutura-Atividade , Propriedades de Superfície
20.
ACS Appl Mater Interfaces ; 13(5): 6906-6918, 2021 Feb 10.
Artigo em Inglês | MEDLINE | ID: mdl-33523643

RESUMO

A feasible and efficient membrane for long-term treatment of complex oily wastewater is especially in demand, but its development still remains a challenge because of serious membrane fouling and incomplete/destructive reclamation methods. Herein, an interpenetrating TiO2 nanorod-decorated membrane with self-locked and self-cleaning properties is rationally fabricated via coaxial electrospinning and hydrothermal synthesis. The self-locked membrane shows full reinstatement of the original state and exhibits satisfactory mechanical strength, superhydrophilicity, underwater superoleophobicity, and robust solvent resistance, which endow the membrane with successful separation for 16 types of highly emulsified oil-in-water emulsions (e.g., surfactant-free; anionic, cationic, and nonionic surfactant-stabilized). Moreover, successful sequencing treatment of soluble organic emulsions using the separated "bait-hook-destroy" strategy indicates that the pristine membrane can be used to treat multipollutant wastewater with various limits. Most importantly, the fouled membrane can easily be reinstated by light irradiation without reduction of both mechanical strength and separation performance. As a proof of concept, the as-synthesized membrane shows an ultrahigh flux over 5000 L m-2 h-1 with a removal efficiency of >99.92%. The present development would provide a highly efficient strategy for the fabrication of an inorganic-organic revivable electrospinning membrane for various applications.

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