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1.
Chemistry ; 20(33): 10220-2, 2014 Aug 11.
Article in English | MEDLINE | ID: mdl-25042886

ABSTRACT

Amine-functionalization of TiO2 nanoparticles, through a solvothermal approach, substantially increases the affinity of CO2 on TiO2 surfaces through chemisorption. This chemisorption allows for more effective activation of CO2 and charge transfer from excited TiO2 , and significantly enhances the photocatalytic rate of CO2 reduction into methane and CO.

2.
Nanoscale ; 6(10): 5217-22, 2014 May 21.
Article in English | MEDLINE | ID: mdl-24687039

ABSTRACT

Direct evidence of plasmon-enhanced H2 generation is observed in photocatalytic water reduction by using TiO2 electrospun nanofibers co-decorated with Au and Pt nanoparticles through dual-beam irradiation. The Au/Pt/TiO2 nanofibers exhibit certain activity for H2 generation under single irradiation at 420 nm that excites the defect/impurity states of TiO2. Significantly, when secondary irradiation at 550 nm is introduced to simultaneously excite Au SPR, we observed 2.5 times higher activity for H2 generation. Further investigation by finely controlling the irradiation wavelengths reveals that the enhancement factor on the photocatalytic activity for H2 generation is directly correlated with the plasmon absorption band of the Au nanoparticles in the Au/Pt/TiO2 nanofibers. The control experiments with different sacrificial agents suggest that the hot plasmonic electrons of Au are responsible for the enhanced photocatalytic activity that can be magnified when TiO2 is simultaneously excited.

3.
Chemistry ; 20(10): 2742-5, 2014 Mar 03.
Article in English | MEDLINE | ID: mdl-24677361

ABSTRACT

Triangular Au­Ag2S hybrid nanoframes were successfully synthesised by using Ag nanoprisms as templates through gold coating, etching and sulfuration. These Au­Ag2S hybrid nanoframes exhibit effective photocurrent responses for potential photoelectrochemical applications.

4.
Phys Chem Chem Phys ; 15(42): 18363-6, 2013 Nov 14.
Article in English | MEDLINE | ID: mdl-24072333

ABSTRACT

We report an economic and noble-metal-free artificial photosynthetic system, consisting of g-C3N4 as a photosensitizer and a photocatalyst, and cobaloxime as a co-catalyst, for H2 generation. This system allows for effective electron transfer from excited g-C3N4 to Co(III)(dmgH)2pyCl to generate reduced cobaloxime intermediate species for efficient H2 evolution. Transient fluorescence studies reveal that the presence of cobaloxime and TEOA promotes the population of excited electrons to transfer from g-C3N4, which is responsible for the high photocatalytic activity of this g-C3N4-cobaloxime conjugation system.


Subject(s)
Biomimetics , Graphite/chemistry , Hydrogen/chemistry , Nanostructures/chemistry , Organometallic Compounds/chemistry , Photosynthesis , Catalysis , Models, Molecular , Molecular Conformation , Semiconductors
5.
ACS Appl Mater Interfaces ; 4(1): 418-23, 2012 Jan.
Article in English | MEDLINE | ID: mdl-22141400

ABSTRACT

Au-BiVO(4) heterogeneous nanostructures have been successfully prepared through in situ growth of gold nanoparticles on BiVO(4) microtubes and nanosheets via a cysteine-linking strategy. The experimental results reveal that these Au-BiVO(4) heterogeneous nanostructures exhibit much higher visible-light photocatalytic activities than the individual BiVO(4) microtubes and nanosheets for both dye degradation and water oxidation. The enhanced photocatalytic efficiencies are attributed to the charge transfer from BiVO(4) to the attached gold nanoparticles as well as their surface plasmon resonance (SPR) absorption. These new heteronanostructures are expected to show considerable potential applications in solar-driven wastewater treatment and water splitting.

6.
Nanomedicine ; 7(4): 428-34, 2011 Aug.
Article in English | MEDLINE | ID: mdl-21215328

ABSTRACT

Calcium phosphates (CPs) are regarded as the most biocompatible inorganic biomaterials; however, they are limited in the drug-delivery applications, especially for hydrophobic drugs. Achieving high drug-loading capacity and a controllable drug-release property are two main challenges. In this study we report a strategy for the preparation of novel drug delivery systems based on a concerted process in which the formation of the CP nanocarriers and the drug storage are accomplished in one step in mixed solvents of water and ethanol. The key advantage of this strategy is that the formation of CP nanocarriers and in situ loading of the drug occur simultaneously in the same reaction system, which makes it possible to achieve ultrahigh drug-loading capacity and prolonged drug release due to ultrahigh specific surface area and numerous binding sites of the CP nanocarriers. A series of hydrophobic drug-delivery systems with adjustable drug-loading capacities and drug-release rates have been successfully synthesized. In addition, the drug-release kinetics of the as-prepared drug-delivery systems have been found in which the cumulative amount of drug release has a linear relationship with the natural logarithm of release time. FROM THE CLINICAL EDITOR: Calcium phosphates (CPs) are highly biocompatible inorganic biomaterials with thus far limited drug-delivery applications. This study reports the preparation of a novel drug delivery system where the formation of CP nanocarriers and in situ loading of the drug occur simultaneously in the same reaction, enabling ultra-high drug-loading.


Subject(s)
Calcium Phosphates/chemistry , Calcium Phosphates/chemical synthesis , Drug Carriers/chemistry , Drug Carriers/chemical synthesis , Hydrophobic and Hydrophilic Interactions , Nanotechnology
7.
Nanoscale Res Lett ; 5(4): 781-5, 2010 Feb 14.
Article in English | MEDLINE | ID: mdl-20671783

ABSTRACT

The P123/ACP nanocomposite with sizes less than 100 nm consisting of triblock copolymer P123 and amorphous calcium phosphate (ACP) has been prepared by using an aqueous solution containing CaCl2, (NH4)3PO4, and P123 at room temperature. The P123/ACP nanocomposite is used as the nanocarrier for hydrophobic drug ibuprofen, based on the combined advantages of both amphiphilic block copolymer and calcium phosphate delivery system. The P123/ACP nanocomposite has a much higher ibuprofen loading capacity (148 mg/g) than the single-phase calcium phosphate nanostructures. The drug release percentage of the P123/ACP nanocomposite in simulated body fluid reaches about 100% in a period of 156 h, which is much slower than that of single-phase calcium phosphate nanostructures. It is expected that the P123/ACP nanocomposite is promising for the application in the controlled delivery of hydrophobic drugs.

8.
Dalton Trans ; 39(18): 4435-9, 2010 May 14.
Article in English | MEDLINE | ID: mdl-20422101

ABSTRACT

We report room-temperature preparation of poly(ethylene glycol)-block-polylactide (PEG-PLA)/calcium phosphate (CP) nanocomposites with a porous morphology. The reaction time and concentration of the inorganic ingredients play an important role in the morphology and chemical composition of the nanocomposite. Thermogravimetry analysis shows that there is approximately 8.5 wt.% of PEG-PLA block copolymer in the nanocomposite. A typical anti-inflammatory drug, ibuprofen, is used to evaluate the drug loading ability and the release behavior of the porous PEG-PLA/CP nanocomposite. The experiments reveal that the nanocomposite has a higher drug loading capacity and favorable drug release property. The drug release kinetics of the porous PEG-PLA/CP nanocomposite is discussed as a three-stage process. The as-prepared porous PEG-PLA/CP nanocomposite is promising for application in drug delivery.


Subject(s)
Calcium Phosphates/chemistry , Drug Carriers/chemical synthesis , Nanocomposites/chemistry , Polyesters/chemistry , Polyethylene Glycols/chemistry , Anti-Inflammatory Agents, Non-Steroidal/administration & dosage , Drug Carriers/chemistry , Ibuprofen/administration & dosage , Kinetics , Porosity , Temperature
9.
Carbohydr Res ; 345(8): 1046-50, 2010 May 27.
Article in English | MEDLINE | ID: mdl-20381016

ABSTRACT

Preparation of nanocomposites was carried out using microcrystalline cellulose, CaCl(2), and NaH(2)PO(4) in N,N-dimethylacetamide (DMAc) solvent by a microwave-assisted method at 150 degrees C. XRD results showed that the nanocomposites consisted of cellulose and hydroxyapatite (HA). The cellulose existed as a matrix in the nanocomposites. SEM and TEM analysis showed that HA nanorods were homogeneously dispersed in the cellulose matrix. The effects of the microwave heating time on the products were investigated. This method has advantages of being simple, rapid, low-cost, and environmentally friendly.


Subject(s)
Acetamides/chemistry , Cellulose/chemistry , Durapatite/chemistry , Microwaves , Nanocomposites/chemistry , Solvents/chemistry , Microscopy, Electron, Scanning , Microscopy, Electron, Transmission , Nanocomposites/ultrastructure
11.
Nanoscale Res Lett ; 6(1): 1, 2010 Aug 18.
Article in English | MEDLINE | ID: mdl-21711573

ABSTRACT

A simple one-step NaCl-assisted microwave-solvothermal method has been developed for the preparation of monodisperse α-Fe2O3 mesoporous microspheres. In this approach, Fe(NO3)3 · 9H2O is used as the iron source, and polyvinylpyrrolidone (PVP) acts as a surfactant in the presence of NaCl in mixed solvents of H2O and ethanol. Under the present experimental conditions, monodisperse α-Fe2O3 mesoporous microspheres can form via oriented attachment of α-Fe2O3 nanocrystals. One of the advantages of this method is that the size of α-Fe2O3 mesoporous microspheres can be adjusted in the range from ca. 170 to ca. 260 nm by changing the experimental parameters. High photocatalytic activities in the degradation of salicylic acid are observed for α-Fe2O3 mesoporous microspheres with different specific surface areas.

12.
J Hazard Mater ; 171(1-3): 431-5, 2009 Nov 15.
Article in English | MEDLINE | ID: mdl-19564076

ABSTRACT

We report the microwave-hydrothermal ionic liquid (MHIL) synthesis and photocatalytic property over phenol of ZnFe(2)O(4) nanoparticles. Zn(CH(3)COO)(2).2H(2)O and Fe(NO(3))(3).9H(2)O were used as the zinc and iron sources, respectively, in the presence of CO(NH(2))(2) and the ionic liquid 1-n-butyl-3-methyl imidazolium tetrafluoroborate ([BMIM][BF(4)]). Deionized water was used as a solvent. The ionic liquid [BMIM][BF(4)] and microwave heating temperature have significant influences on the crystal phase of the product. Different dosages of [BMIM][BF(4)] or microwave heating temperature could lead to the formation of different products such as ZnFe(2)O(4) and beta-FeOOH. The MHIL method has the advantages such as simplicity, rapidness and energy saving. The ZnFe(2)O(4) nanoparticles prepared by the MHIL method exhibit high photocatalytic activity for the degradation of phenol, which was up to 73% within 360 min. The TOC measurement confirmed the good photocatalytic efficiency of ZnFe(2)O(4) nanoparticles.


Subject(s)
Ions , Metal Nanoparticles/analysis , Nanotechnology/methods , Phenol/chemistry , Catalysis , Ionic Liquids/chemistry , Metal Nanoparticles/chemistry , Microwaves , Models, Chemical , Solvents , Temperature , Water/chemistry , Water Purification/methods
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