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1.
Molecules ; 28(6)2023 Mar 17.
Artigo em Inglês | MEDLINE | ID: mdl-36985715

RESUMO

Monolithic Al2O3-SiO2 composite aerogels were synthesized by using inexpensive aluminum chloride hexahydrate (AlCl3·6H2O) and tetraethyl orthosilicate (TEOS). By adjusting the molar ratio of Al and Si, the best ratio of high-temperature resistance was found. The resultant aerogels (Al:Si = 9:1) exhibit high thermal performance, which can be identified by the low linear shrinkage of 5% and high specific surface area (SSA) of 283 m2/g at 1200 °C. Alumina in these aerogels mainly exists in the boehmite phase and gradually transforms into the θ-Al2O3 phase in the process of heating to 1200 °C. No α-Al2O3 is detected in the heating process. These Al2O3-SiO2 composite aerogels are derived from a simple, low-priced and safe method. With their high thermal performance, these aerogels will have a wide application in high-temperature field.

2.
Small ; 18(12): e2106712, 2022 03.
Artigo em Inglês | MEDLINE | ID: mdl-35098640

RESUMO

Here, a universal template-activation strategy is proposed to prepare two different types of porous carbonaceous materials for potassium ion hybrid capacitor (PIHC) anode and cathode, which is realized by only changing the type of cation (Na+ and K+ ) in the polysilicic acid-organic mixed hydrogel precursor originating from adding organic acid into Na2 SiO3 and K2 SiO3 solution, respectively. TG-IR data demonstrate that K+ exhibits a stronger etching ability for activating carbonaceous materials during the annealing process. Accordingly, a 3D carbon anode obtained with the assistance of NaOH (NPC-500) exhibits abundant edge-N doping (8.14 at%), displaying a high K-storage capacity of 314.1 mA h g-1 at 0.2 A g-1 and a capacity of 219.3 mA h g-1 at 10 A g-1 after 10000 cycles. A porous carbon particles cathode prepared in the presence of KOH (KCP-800) shows a high specific surface area (1326.8 m2 g-1 ), contributing to high PF6- (de)adsorb capacity of 103.0 mA h g-1 at 1 A g-1 . Remarkably, the assembled NPC//KCP PIHC delivers a high energy density of 137.7 W h kg-1 at a power density of 275.4 W kg-1 even over 20 000 cycles.


Assuntos
Carbono , Potássio , Cátions , Eletrodos , Hidrogéis
3.
Nanotechnology ; 33(6)2021 Nov 19.
Artigo em Inglês | MEDLINE | ID: mdl-34724658

RESUMO

In this study, we synthesised the Ni/single-walled carbon nanotube prepared by the super-growth method (SG-SWCNTs). In this approach, the Ni nanoparticles were immobilised by an impregnation method using the SG-SWCNTs with high specific surface areas (1144 m2g-1). The scanning electron microscopy images confirmed that the SG-SWCNTs exhibit the fibriform morphology corresponding to the carbon nanotubes. In addition, component analysis of the obtained samples clarified that the Ni nanoparticles were immobilised on the surface of the SG-SWCNTs. Next, we evaluated the activity for the reduction of 4-nitoropenol in the presence of the Ni/SG-SWCNTs. Additionally, the Ni/graphene, which was obtained by the same synthetic method, was utilised in this reaction. The rate of reaction activity of the Ni/SG-SWCNTs finished faster than that of the Ni/GPs. From this result, the pseudo-first-order kinetic rate constantkfor the Ni/SG-SWCNTs and the Ni/GPs was calculated respectively at 0.083 and 0.070 min-1, indicating that the Ni/SG-SWCNTs exhibits higher activity.

4.
Molecules ; 26(14)2021 Jul 13.
Artigo em Inglês | MEDLINE | ID: mdl-34299522

RESUMO

Mesoporous silica nanostructures (MSNs) attract high interest due to their unique and tunable physical chemical features, including high specific surface area and large pore volume, that hold a great potential in a variety of fields, i.e., adsorption, catalysis, and biomedicine. An essential feature for biomedical application of MSNs is limiting MSN size in the sub-micrometer regime to control uptake and cell viability. However, careful size tuning in such a regime remains still challenging. We aim to tackling this issue by developing two synthetic procedures for MSN size modulation, performed in homogenous aqueous/ethanol solution or two-phase aqueous/ethyl acetate system. Both approaches make use of tetraethyl orthosilicate as precursor, in the presence of cetyltrimethylammonium bromide, as structure-directing agent, and NaOH, as base-catalyst. NaOH catalyzed syntheses usually require high temperature (>80 °C) and large reaction medium volume to trigger MSN formation and limit aggregation. Here, a successful modulation of MSNs size from 40 up to 150 nm is demonstrated to be achieved by purposely balancing synthesis conditions, being able, in addition, to keep reaction temperature not higher than 50 °C (30 °C and 50 °C, respectively) and reaction mixture volume low. Through a comprehensive and in-depth systematic morphological and structural investigation, the mechanism and kinetics that sustain the control of MSNs size in such low dimensional regime are defined, highlighting that modulation of size and pores of the structures are mainly mediated by base concentration, reaction time and temperature and ageing, for the homogenous phase approach, and by temperature for the two-phase synthesis. Finally, an in vitro study is performed on bEnd.3 cells to investigate on the cytotoxicity of the MNSs.

5.
Mikrochim Acta ; 187(7): 382, 2020 06 12.
Artigo em Inglês | MEDLINE | ID: mdl-32529294

RESUMO

Fully porous silica microspheres (FPSM) with high specific surface area and hierarchical pore as matrix for HPLC were prepared. First, the porous silica nanospheres with controllable particle size and pore diameter were successfully synthesized using a dual-templating approach, the pore size of nanospheres can be increased to 18.4 nm by changing the molar ratios of octyltrimethylammonium bromide (TOMAB) and cetyltrimethyl ammonium bromide (CTAB), which is suitable for separation and analysis of biomolecules without pore enlargement. Then, the micron FPSM with hierarchical pore were synthesized by polymerization-induced colloid aggregation (PICA) using the porous nanospheres as a silicon source, which has a large mesoporous structure (35.2 nm) and high specific surface area (560 m2 g-1). Subsequently, the FPSM modified with octadecyltrichlorosilane were studied as stationary phase for separation of cytochrome C, lysozyme, ribonuclease A, and ovalbumin, bovine serum albumin, and the baseline separation of five proteins was achieved within 1 min. The prepared column was also applied to the fast separation of digests of ovalbumin, and more chromatographic peaks were obtained compared to a commercial column under the same gradient elution conditions. In addition, the static-binding capacity of the functionalized FPSM for bovine serum albumin (BSA) was measured to be 276 mg g-1, which was nearly twice the static adsorption given in literature. Therefore, these FPSM with high specific surface area and hierarchical pore structure are expected to have great potential for the separation of complex biological samples using HPLC. Graphical abstract A synthetic strategy was provided towards FPSM with hierarchical pores and high specific surface area using porous nanospheres as silicon source. The outstanding performance of the FPSM is that it has a high specific surface area while maintaining a large mesoporous size, which overcomes the disadvantage of sacrificing the specific surface area when increasing the pore size of porous silica microspheres prepared by using the traditional PICA method.


Assuntos
Microesferas , Fragmentos de Peptídeos/isolamento & purificação , Proteínas/isolamento & purificação , Dióxido de Silício/química , Adsorção , Animais , Bovinos , Cromatografia Líquida de Alta Pressão , Fragmentos de Peptídeos/química , Porosidade , Proteínas/química , Dióxido de Silício/síntese química , Extração em Fase Sólida
6.
Bioresour Technol ; 395: 130324, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38228220

RESUMO

Converting waste resource into porous carbon toward contaminant capturing is a crucial strategy for realizing "treating waste with waste". Inspired by bread baking process, the soybean meal activated carbon (SAC) with multimodal pore structures was developed via thermally remodeling the pores of waste soybean meal. The obtained SAC-3-800 has ultra-high specific surface area (3536.952 m2/g), as well as a hierarchically porous structure. SAC-3-800 exhibits extremely high adsorption capacity for methylene blue (MB) (3015.59 mg/g), methyl orange (MO) (6486.30 mg/g), and mixed dyes (8475.09 mg/g). The hierarchically porous structure enabled fast adsorption kinetics of SAC-3-800 for MB and MO (∼30 min). Additionally, SAC-3-800 shows excellent dynamic adsorption and regeneration performance, exhibiting great potential for industrial applications. This work showcases a feasible method for synthesizing hierarchically porous carbon with outstanding adsorption performance that can simultaneously achieve efficient treatment of dye-wastewater and value-added utilization of waste resources.


Assuntos
Compostos Azo , Corantes , Poluentes Químicos da Água , Adsorção , Corantes/química , Porosidade , Águas Residuárias , Azul de Metileno/química , Carvão Vegetal , Poluentes Químicos da Água/química
7.
Int J Biol Macromol ; 228: 40-47, 2023 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-36529217

RESUMO

Although extensive research has been focused on porous carbon in supercapacitor, the simple and non-template preparation of high specific surface area (SSA) carbon material with hierarchical porous structure is still a lingering issue. Herein, the cross-linked hierarchical porous carbon with ultra-high SSA of 3184 m2 g-1 is prepared via the sol-gel follows the freeze drying and followed activation process. Agar is used as carbon precursor, L-arginine is nitrogen sources, and the formed gel is activated by KHCO3. The obtained N-doped porous carbon shows a superior specific capacitance of 443.0 F g-1 at 0.5 A g-1 in 6 M KOH, and exhibits an excellent rate capability (255 F g-1 at 50 A g-1). Furthermore, due to the combined synergistic effect of high SSA, hierarchical porous structure and N doping, the symmetric supercapacitor that assembled with the prepared gel electrolyte of Agar-Na2SO4 achieves a superior energy density of 35.5 Wh kg-1 and a long cycle life with the capacitance retention of 99.7% after 20,000 cycles. This work provides an efficient and simple method to prepare ultra-high surface area, hierarchical porous structure carbon materials for high performance supercapacitor.


Assuntos
Arginina , Polissacarídeos , Ágar , Porosidade , Carbono
8.
Materials (Basel) ; 16(8)2023 Apr 12.
Artigo em Inglês | MEDLINE | ID: mdl-37109882

RESUMO

When impregnated with manganiferous precursors, γ-Al2O3 may be converted into α-Al2O3 under relatively mild and energy-saving conditions. In this work, a manganese assisted conversion to corundum at temperatures as low as 800 °C is investigated. To observe the alumina phase transition, XRD and solid-state 27Al-MAS-NMR are applied. By post-synthetical treatment in concentrated HCl, residual manganese is removed up to 3 wt.-%. Thereby, α-Al2O3 with a high specific surface area of 56 m2 g-1 is obtained after complete conversion. Just as for transition alumina, thermal stability is an important issue for corundum. Long-term stability tests were performed at 750 °C for 7 days. Although highly porous corundum was synthesized, the porosity decreased with time at common process temperatures.

9.
Carbohydr Polym ; 286: 119287, 2022 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-35337508

RESUMO

In this paper, the two-step activation Eucommia wood tar-based activated carbon (ETAC), cellulose nanofibers (CNF) and reduced graphene oxide (rGO) were assembled to form composite aerogel in mild condition. Impressively, the doping of optimizing ETAC greatly improved the overall specific surface area (SSA) of the aerogel, and the CNF extracted from Eucommia ulmoides wood was used to enhance the mechanical properties of graphene aerogel. Besides, the composite aerogels with high content of ETAC (67% of mass ratio) possessed efficient MnOx deposition capability (1540 mg/g), which could assemble an asymmetric free-binder supercapacitor, exhibiting an ultrahigh specific capacitance and prominent cycling stability. This work offered a feasible method to fabricate free-binder composite aerogels with excellent electrochemical property for broad applications in supercapacitors.

10.
Chemosphere ; 309(Pt 2): 136741, 2022 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-36209865

RESUMO

Excellent performances of various materials often depend on high specific surface areas. Therefore, increase of specific surface areas is one of the most important means to improve the properties and performances of materials. Herein, we report a facile strategy to prepare novel composite materials of zeolites and hydrotalcite-like layered double hydroxides, with high specific surface areas. The composites with a rose-like morphology were synthesized hydrothermally by adding synthetic zeolites to the raw materials used for the formation of hydrotalcite. The resultant composites were shown to contain two distinct layered double hydroxides with different Mg/Al molar ratios. Nitrogen (N2) adsorption-desorption measurements showed that the specific surface areas and the pore volumes of these composites increased by an order of magnitude in comparison with hydrotalcite. The new composites were shown to be capable of effectively removing Cr(VI), Cu(II) and methylene blue from aqueous environments and had better performances for the latter two contaminants than hydrotalcite. Moreover, this strategy potentially opens up the synthesis of new composite materials with tunable compositions and enhanced properties for environmental and other applications.

11.
Environ Sci Pollut Res Int ; 29(9): 13098-13113, 2022 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-34569006

RESUMO

It is rather essential to design porous carbon adsorbents with high CO2 capture performance for improving global warming and climate change. Activated carbon spheres with high specific surface area and hierarchical porous texture were prepared from polystyrene-based macroreticular resin spheres due to their low ash and mechanical stability by air pre-oxidization and steam activation. The as-prepared carbon spheres had a specific surface area of 1274.95 m2 g-1, total pore volume of 1.09 cm3 g-1 and micropore volume of 0.47 cm3 g-1. Moreover, these carbon spheres showed a hierarchical porous texture composed of ultrafine micropores (0.5-1 nm), micropores (1-2 nm), mesopores (10-50 nm) and macropores (50-100 nm). A CO2 adsorption capacity of 2.82 mmol g-1 for carbon spheres can be obtained at 30 °C and 1 atm. Further, after introducing nitrogen-containing functional groups by gaseous ammonia at 600 °C, these carbon spheres (NPSRCSs) exhibited a high CO2 adsorption capacity of 3.2 mmol g-1. In addition, excellent cyclic stability, low hygroscopicity and regenerability temperature suggested these carbon spheres were favorable for CO2 capture.


Assuntos
Dióxido de Carbono , Carvão Vegetal , Adsorção , Poliestirenos , Porosidade
12.
Materials (Basel) ; 14(7)2021 Mar 30.
Artigo em Inglês | MEDLINE | ID: mdl-33808233

RESUMO

A large amount of cow hair solid waste is produced in leather production, and a reasonable treatment should be developed to reduce the pollution. In this study, cow hair waste was utilized as the carbon precursor, and N2 was determined to be the most appropriate atmosphere for biochar preparation. We performed a comparison of the properties of biochars that were prepared with different methods, including direct pyrolysis, KOH activation, and the MgO template method. The characterization results show that the highest specific surface area reaches 1753.075 m2/g. Subsequently, the keratin that was extracted from cow hair and purified was used to prepare a biochar with the MgO template method, obtaining an orderly sponge structure. The biochar from cow hair waste was further used to absorb direct blue dye wastewater, and its adsorption capacity reached 1477 mg/g after 10 h with a high efficiency of regeneration. This study successfully utilized keratin-containing hair waste and provides a new source for synthesizing carbon materials for dye wastewater treatment.

13.
J Hazard Mater ; 416: 125896, 2021 08 15.
Artigo em Inglês | MEDLINE | ID: mdl-34492834

RESUMO

Cork, a porous biomass material, is consist of thin-walled hollow prismatic cells arranged into a compact and orderly honeycomb-like structure and could be applied as an adsorption material. Here, cork-activated carbons (CACs) with a fluffy honeycomb-like structure were synthesized by two-step pyrolysis with solid KOH chemical activation to rapidly and efficiently adsorb methylene blue (MB) (maximum wavelength: 664 nm). The structure, morphology and surface functional groups of the CACs were characterized using BET, SEM, and FTIR analysis. The results show that the CACs have a well-developed hierarchical porous structure and an ultra-high specific surface area of 2864.9 m2/g, which would facilitate the efficient diffusion and adsorption of MB molecules onto CACs. MB adsorption performance results show that the CACs have an outstanding maximum MB adsorption capacity (1103.68 mg/g) and fast adsorption kinetics (800 mg/L, 99.8% in 10 min), indicating that CACs possess significant advantages compared with most other adsorbents previously reported. The adsorption mechanism was studied by various kinetic models, isothermal models and thermodynamic models. Langmuir model is the most adapted to describe the adsorption process, indicating that the MB molecules are uniformly adsorbed on CAC's surface in a single layer. Moreover, MB adsorption by the CACs was an endothermic, spontaneous and randomly increasing adsorption. The regeneration test showed that the uptake of MB onto CACs can still reached 580 mg/g after three adsorption-desorption cycles, demonstrating the excellent reusability of CACs. The continuous adsorption performance of MB onto CACs was evaluated by a packed column test, which further confirmed its potential as an adsorbent for dye wastewater purification.


Assuntos
Poluentes Químicos da Água , Purificação da Água , Adsorção , Biomassa , Carvão Vegetal , Cinética , Azul de Metileno
14.
Acta Biomater ; 134: 576-592, 2021 10 15.
Artigo em Inglês | MEDLINE | ID: mdl-34280558

RESUMO

The purpose of this study was to investigate the delivery of poorly water-soluble non-steroidal anti-inflammatory drugs (NSAIDs) by carboxyl-functionalized mesoporous silica nanoparticles (MSN-COOH) with high specific surface area (SBET). In this study, MSN-COOH was prepared by collaborative self-assembly using cetyltrimethylammonium bromide (CTAB) as template and hydrolysis (3-triethoxyl-propyl) succinic anhydride (TESPSA) as co-structure auxiliary directing agent (CSDA). The drug delivery systems were constructed with NSAIDs including Nimesulide (NMS) and Indomethacin (IMC) as model drugs. Moreover, the characterization techniques, hemolysis and bio-adsorption testes, in vitro drug release and in vivo biological studies of MSN-COOH were also carried out. The characterization results showed that MSN-COOH is spheres with clearly visible irregular honeycomb nanopores and rough surface (SBET: 1257 m2/g, pore volume (VP): 1.17 cm3/g). After loading NMS/IMC into MSN-COOH with high drug loading efficiency (NMS: 98.7 and IMC: 98.2%), most crystalline NMS and IMC converted to amorphous phase confirmed using differential scanning calorimeter (DSC) and X-ray power diffraction (XRD) analysis. Meanwhile, MSN-COOH significantly increased the dissolution of NMS and IMC compared with non-functionalized mesoporous silica nanoparticles (MSN), which was also confirmed by wettability experiments. The results of in vivo biological effects showed that MSN-COOH had higher bioavailability of NMS and IMC than MSN, and exerted strong anti-inflammatory effects by delivering more NMS and IMC in vivo. STATEMENT OF SIGNIFICANCE: This study successfully prepared MSNs-COOH (mesoporous silica nanoparticles modified with negatively charged carboxyl groups on the surface and in the pores) with high specific surface area and pore volume by using the negatively charged carboxyl group (hyd-TESPSA) and the positively charged CTAB self-assembled through electrostatic attraction under alkaline conditions. The drug delivery systems were constructed with Nimesulide (NMS) and Indomethacin (IMC) as model drugs. The results showed MSNs-COOH had high drug loading capacity and also exhibited good in vitro drug release properties. Interestingly, NMS loaded MSNs-COOH also had a potential pH responsive release effect. In vivo biological studies revealed that NMS/IMC loaded MSNs-COOH could evidently improve the bioavailability and played the strong anti-inflammatory effects.


Assuntos
Nanopartículas , Dióxido de Silício , Anti-Inflamatórios não Esteroides/farmacologia , Portadores de Fármacos , Sistemas de Liberação de Medicamentos , Porosidade , Água
15.
Nanomaterials (Basel) ; 11(5)2021 May 17.
Artigo em Inglês | MEDLINE | ID: mdl-34067894

RESUMO

The alkaline activation of a carbonized graphene oxide/dextrin mixture yielded a carbon-based nanoscale material (AC-TR) with a unique highly porous structure. The BET-estimated specific surface area of the material is 3167 m2/g, which is higher than the specific surface area of a graphene layer. The material has a density of 0.34 g/cm3 and electrical resistivity of 0.25 Ω·cm and its properties were studied using the elemental analysis, transmission electron microscopy (TEM), electron diffraction (ED), X-ray diffraction (XRD), Raman spectroscopy, X-ray photoelectron spectroscopy (XPS), X-ray induced Auger electron spectroscopy (XAES), and electron energy loss spectroscopy (EELS) in the plasmon excitation range. From these data, we derive an integral understanding of the structure of this material. The concentration of sp3 carbon atoms was found to be relatively low with an absolute value that depends on the measurement method. It was shown that there is no graphite-like (002) peak in the electron and X-ray diffraction pattern. The characteristic size of a sp2-domain in the basal plane estimated from the Raman spectra was 7 nm. It was also found that plasmon peaks in the EELS spectrum of AC-TR are downshifted compared to those of graphite.

16.
Environ Sci Pollut Res Int ; 27(14): 16763-16773, 2020 May.
Artigo em Inglês | MEDLINE | ID: mdl-32141002

RESUMO

Removal of toxic Cr(VI) from contaminated water is significant for environmental protection. High efficient adsorbents with outstanding adsorption performance are highly demanded. Herein, we reported that window-like structured carbon hollow fibers (WL-CHF) derived from Enteromorpha prolifera could capture toxic Cr(VI) from aqueous solutions with high adsorption capacity, fast adsorption rate, and excellent recyclable performance. The excellent adsorption performance could be attributed to the unique structure that combines a variety of advantages: large specific surface area, fast diffusion processes, and easy access of adsorption sites for Cr(VI). In addition, the adsorption process was fitted well with pseudo-second-order model and Langmuir isotherm model. The potential mechanism on Cr(VI) removal includes reduction-cation exchange and electrostatic interaction with surface oxygen-containing functional groups. This study highlights new opportunities for designing adsorbents for Cr(VI) removal from Cr-polluted water.


Assuntos
Poluentes Químicos da Água/análise , Purificação da Água , Adsorção , Fibra de Carbono , Cromo/análise , Cinética
17.
Environ Sci Pollut Res Int ; 27(15): 17986-17996, 2020 May.
Artigo em Inglês | MEDLINE | ID: mdl-32170614

RESUMO

Compared with As(V), As(III) is a tricky issue worldwide for its higher toxicity and more difficult to remove in aqueous solution. In present study, a novel CeOx/MnOy nanoparticles anchored layered structural TiO2 pillared montmorillonite (TiO2-Mt-Ce-Mn) was fabricated and applied as an efficient absorbent for As(III) removal. Under the condition of the initial As(III) concentration = 20 mg/L and adsorbent dose = 0.4 g/L, TiO2-Mt-Ce-Mn with a high specific surface area (148.099 m2/g) has an outstanding adsorption capacity (46.58 mg/g) for As(III) at pH 4.2, and the effect of oxy-anions on adsorption efficiency is slight except for H2PO4-. Interestingly, the layered structure provides sufficient attachment space for CeOx/MnOy nanoparticles, while CeOx/MnOy nanoparticles in turn endows TiO2-Mt a high redox potential, which further facilitates the oxidation of As(III), and this significantly reduces the toxicity of wastewater. The adsorption mechanism includes the oxidation of As(III) to As(V) by both CeOx/MnOy nanoparticles and TiO2 and effective adsorption of the residual As(III) and the formed As(V) subsequently. In addition, the adsorption efficiency of TiO2-Mt-Ce-Mn can still maintain 79.6% after five cycles through a facile regeneration method. Thus, the nanocomposite with low-cost synthesis process, high adsorption capacity, and regenerability is a promising candidate for As(III) treatment of wastewater.


Assuntos
Arsênio , Nanopartículas , Poluentes Químicos da Água/análise , Purificação da Água , Adsorção , Bentonita , Titânio , Águas Residuárias
18.
J Hazard Mater ; 384: 121278, 2020 02 15.
Artigo em Inglês | MEDLINE | ID: mdl-31581021

RESUMO

Heavy metal removal by environmental-friendly nanostructured TiO2 adsorbent is a promising strategy to facilitate wastewater treatment. Here, a boiling water synthetic approach is explored to prepare mesoporous phosphated TiO2 (PTO) used for Cr(III) adsorption in polluted water. We obtain mesoporous 8-PTO (synthesized with 8% molar ratio of H3PO4) with a high specific surface area (278 m2/g), narrow size distribution (<5 nm), low pHzpc (pH of zero point of charge) value (∼1.0), and abundant surface hydroxyl group, which is attributed to the introduction of H3PO4 during the hydrolysis process of TiCl4 in boiling water. Importantly, the obtained 8-PTO shows better thermal stability than pure TiO2 and retains mesoporous structure after thermal treatment owning to [PO4] tetrahedral incorporated into the network of [TiO6] octahedral. The optimized 8-PTO exhibits superior Cr(III) adsorption up to 92 mg/g in sewage, which makes it one of the best materials among TiO2 adsorbent known for Cr(III) Removal (10-83 mg/g). Additionally, the as-prepared mesoporous 8-PTO adsorbent possesses an excellent reusability without significant degradation and can largely avoid the generation of secondary contaminants. A linear relationship (R2 = 0.9985) between adsorption capacity and hydroxyl content percentage of different PTO samples is revealed, indicating that the surface hydroxyl groups play a decisive role in the adsorption process. This study provides a facile approach to synthesize high specific surface area mesoporous phosphated TiO2 with rich surface functional groups for efficient Cr(III) removal in sewage.

19.
Materials (Basel) ; 12(8)2019 Apr 23.
Artigo em Inglês | MEDLINE | ID: mdl-31018566

RESUMO

High theoretical capacity and low-cost copper sulfide (CuxS)-based anodes have gained great attention for advanced sodium-ion batteries (SIBs). However, their practical application may be hindered due to their unstable cycling performance and problems with the dissolution of sodium sulfides (NaxS) into electrolyte. Here, we employed metal organic framework (MOF-199) as a sacrificial template to fabricate nanoporous CuxS with a large surface area embedded in the MOF-derived carbon network (CuxS-C) through a two-step process of sulfurization and carbonization via H2S gas-assisted plasma-enhanced chemical vapor deposition (PECVD) processing. Subsequently, we uniformly coated a nanocarbon layer on the Cu1.8S-C through hydrothermal and subsequent annealing processes. The physico-chemical properties of the nanocarbon layer were revealed by the analytical techniques of high-resolution transmission electron microscopy (HRTEM), energy-dispersive X-ray spectroscopy (EDS), and scanning electron microscopy (SEM). We acquired a higher SIB performance (capacity retention (~93%) with a specific capacity of 372 mAh/g over 110 cycles) of the nanoporous Cu1.8S-C/C core/shell anode materials than that of pure Cu1.8S-C. This encouraging SIB performance is attributed to the key roles of a nanocarbon layer coated on the Cu1.8S-C to accommodate the volume variation of the Cu1.8S-C anode structure during cycling, enhance electrical conductivity and prevent the dissolution of NaxS into the electrolyte. With these physico-chemical and electrochemical properties, we ensure that the Cu1.8S-C/C structure will be a promising anode material for large-scale and advanced SIBs.

20.
ACS Appl Mater Interfaces ; 10(34): 28918-28927, 2018 Aug 29.
Artigo em Inglês | MEDLINE | ID: mdl-30070477

RESUMO

Recently, nanostructured porous carbons are attracting significant interest in various important applications. However, a green and innovative method to fabricate hierarchically porous-structured carbon is still a challenge. In the present work, hierarchically porous carbon microspheres (HCMs) were prepared by pyrolyzing the chitin microspheres fabricated from a chitin/chitosan blend solution, in which chitosan was used as a forming agent of nanopores/nanochannels to construct the microspheres. The HCM displayed hierarchical porous structure and improved specific surface area of 1450 m2/g. For the application of HCM in hybrid electrode materials as supercapacitors, polyaniline (PANI) nanoclusters were further deposited on the surface of HCM. A symmetric supercapacitor based on HCM-PANI exhibited high rate capability with retaining over 64% of the capacitance as the scan rate increased from 2 to 500 mV/s. This work introduced a distinctive and green method to fabricate hierarchically porous carbon materials, having considerable application prospect for energy storage.

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