Your browser doesn't support javascript.
Mostrar: 20 | 50 | 100
Resultados 1 - 17 de 17
Filtrar
Filtros adicionais











Intervalo de ano
1.
J Nanosci Nanotechnol ; 20(2): 802-809, 2020 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-31383075

RESUMO

AgIO3/Ag2O/Ag nanocomposites with enhanced photocatalytic activities were synthesized by a onestep coprecipitation method at room temperature. The optimum hybrid of AgIO3/Ag2O = 1.25:1 with Ag nanoparticles (Ag NPs) loading (denoted as AA125) exhibited superior photocatalytic activity, demonstrating 97.19% tetracycline (TC) degradation within 60 min under simulated solar irradiation. This was approximately 10.44 and 2.63 times higher than that of pure Ag2O and AgIO3, respectively. The advanced photocatalytic activity can be ascribed to the synergetic effects of the heterostructured AgIO3/Ag2O/Ag and the strong surface plasmon resonance (SPR) effect of Ag NPs generated on the surface, which improved the separation and transfer efficiency of photoinduced electron-hole pairs. The results from radical scavenger experiments indicated that the degradation of TC was driven mainly by the participation of superoxide radical (·O-2).

2.
J Nanosci Nanotechnol ; 19(8): 5150-5157, 2019 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-30913829

RESUMO

Constructing heterojunction is an effective way to enhance the catalytic activities of semiconductor photocatalyst owing to its special synergistic effect. In this study, a novel p-n heterostructured CdWO4/BiOCl nanocomposites were synthesized by a facile hydrothermal and subsequently chemistry bath method. The photocatalytic performance of CdWO4/BiOCl heterojunctions was investigated by degrading phenol and RhB under simulated solar light irradiation. Highly improved photocatalytic activities were achieved on all CdWO4/BiOCl heterojunctions compared with both pure CdWO4 and BiOCl. The CdWO4/BiOCl heterojunction with optimal mole ratio of 25% CdWO4 displayed the highest photoactivity with RhB and phenol being completely degraded in 15 min and 6 h, respectively. Mechanism analysis revealed that the interface of p-n heterojunction of CdWO4/BiOCl composites can produce spontaneously electric field which can effectively separate photogenerated electrons and holes. Moreover, the active species research demonstrated that holes and superoxide radicals proved to be the principal active species during the photocatalytic process. This work demonstrated that the CdWO4/BiOCl photocatalyst may be a promising material for purifying the organic contaminant in practical application.

3.
J Nanosci Nanotechnol ; 19(8): 5287-5294, 2019 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-30913846

RESUMO

3D hierarchical structure BiOX(X ═ Cl, Br)-(CMC) assembled from 2D nanosheets with {010} facets exposed have been successfully synthesized by the assistance of biomass solvent CMC-Na. All the nitrogen adsorption isotherms and photoelectrochemical results reflected that BiOX(X Cl, Br)-(CMC) exhibit higher specific surface area, superior optical absorption efficiency and separation efficiency of photoinduced electron-hole than BiOX(X═Cl, Br) 2D nanosheets exposed with {001} facets. Besides, 96.5% and 60.3% of tetracycline hydrochloride (TC) were photodegradated in 60 minutes under the visible light irradiation catalyzed by BiOBr-(CMC) and BiOCl-(CMC), which is much better than BiOBr and BiOCl. The formation and enhanced photocatalytic activity of 3D hierarchical structure BiOX-(CMC) may be ascribe to the bi-functional groups of CMC, which can affect the crystallization process and morphology of BiOX. According to the merit of environmental friendly and improved photocatalytic activity of the 3D hierarchitecture, we believe that this work broadens the possibility of designing efficient BiOX photocatalyst with {010} facets exposed.

4.
J Nanosci Nanotechnol ; 19(7): 4020-4025, 2019 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-30764964

RESUMO

In this work, platinum nanoparticles were modified on graphite-like carbon nitride (g-C3N4) surface via a simple one-pot deposition reduction method, and the prepared Pt/g-C3N4 was used as electrode materials for phenol sensing. The morphology and crystallographic structure of Pt/g-C3N4 were characterized by Scanning transmission electron microscope (STEM) and X-ray diffraction (XRD). The electrochemical performance of Pt/g-C3N4 toward phenol was investigated in details and the results showed that the Pt/g-C3N4 sensor had favorable sensing ability for phenol detection. Under the optimum parameters, the electrochemical sensor had a wide range of 2 to 20 µM, lower detection limits of 0.667 µM (S/N═3), and higher sensitivity of 1.21084 mA µM-1 in phenol detection, indicating the excellent capability of the newly developed sensor to determine phenol. Moreover, the design of the Pt/g-C3N4 sensor may provide a potential material for actual application in phenol detection due to its merits of simplicity, reliability, sensitivity and low-cost.

5.
J Nanosci Nanotechnol ; 18(7): 4858-4864, 2018 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-29442666

RESUMO

An electrochemical palladium/ferric oxide (Pd/Fe2O3) nanocomposite modified glassy carbon electrode (GCE) was fabricated by hydrothermal method of Fe2O3 and electrochemical deposition of palladium nanoparticles, respectively. As-prepared Pd/Fe2O3 composite modified electrode exhibits enhanced electrocatalytic activity towards the catalytic oxidation of nitrite compared to Fe2O3, PdNPs modified electrodes and bare electrode. The parameters such as the influence of amount of Pd nanoparticles deposition onto the Pd/Fe2O3 modified electrode (ME) and effect of solution pH were investigated and discussed in detail. Under the optimal conditions, the Pd/Fe2O3 modified GCE can be used to detect nitrite concentration in a wide linear range of 10 and 1000 µM with the detection limit of 0.1 µM. The presence of Cu2+, Na+, Cl-, PO3-4 SO2-4, Mg2+ K+, NO-3, and NH+4 showed a trivial effect on the response of nitrite determination, revealing that developed modified electrode has an excellent anti-interference ability to common ions. It also shows good stability and reproducibility.

6.
J Nanosci Nanotechnol ; 18(8): 5575-5581, 2018 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-29458612

RESUMO

Bi2MoO6-BiOCl nanoplate composites were successfully synthesized by a simple solvothermal process. The morphology, microstructure and optical properties of the as-prepared Bi2MoO6-BiOCl nanocomposites were characterized using transmission electron microscopy (TEM), X-ray diffraction (XRD) and UV-Vis diffuse reflection spectroscopy (DRS). A noteworthy enhancement in the visible-light-responsive photocatalytic degradation of RhB was observed over the Bi2MoO6-BiOCl nanocomposites compared to its individual components. The enhanced photocatalytic performance of Bi2MoO6-BiOCl nanocomposites could be attributed to the heterojunction interface in the composite, which can both efficiently separate photogenerated electron-hole pairs and also restrain the recombination of photoinduced charges.

7.
J Nanosci Nanotechnol ; 18(6): 4065-4071, 2018 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-29442744

RESUMO

Herein, a novel visible-light-driven heterojunction AgI/WO3 nanocomposite was successfully prepared using a facile two-step hydrothermal-precipitation process and applied for photodegradation of organic pollutants. The information of phase structures, morphology, optical properties of the asprepared samples was analysed in detail by XRD, TEM, EDS, STEM, DRS measurement and so on. Formation of the heterostructure and intimate interactions between AgI and WO3 can promote highly effective photogenerated electron-hole pairs separation, which enable the heterojuctions to perform excellent photocatalytic activity as greatly enhanced photocatalysts compared to that of pristine AgI and WO3 for decomposing Rhodamine B (RhB) dye under visible light irradiation. In addition, the AgI/WO3 (1:1) nanocomposites exhibit optimal photocatalytic activity. Moreover, the as-prepared samples exhibit good stability, which is favorable for its potential application. Additionally, we have an analysis on a possible photocatalytic mechanism based on trapping experiments together with other experimental results.

8.
J Nanosci Nanotechnol ; 18(5): 3585-3591, 2018 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-29442870

RESUMO

An electrochemical sensor ground on nickel oxide (NiO) nanoparticles and multi-walled carbon nanotubes (MWCNTs) was exploited for the detection of nitrite. Scanning electron microscopy (SEM) ensure the morphology of the nanocomposite consisted of NiO nanoparticle and MWCNTs. High Resolution Transmission electron microscopy (HR-TEM) reveals that the structure of NiO nanoparticles and MWCNTs. Scanning transmission electron microscopy (STEM) persuasively verified presence of the C, Ni and O element. The electrochemical character of the nanocomposite were researched by cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS), and the behavior of electrochemical oxidation to nitrite on NiO/MWCNTs/CP was explored by chronoamperometry. In tests, the NiO/MWCNTs/CP shown a sensitive current response toward nitrite, the oxidation peak current are linearly related to nitrite concentration in the range from 10-6 M to 10-4 M (R = 0.997) with a sensitivity of 3.53 µA µM-1 and a detection limit of 0.25 µM (S/N = 3). The validity of utilizing the proposed electrode to determine nitrite in tap water was also demonstrated.

9.
Phys Chem Chem Phys ; 17(43): 29354-62, 2015 Nov 21.
Artigo em Inglês | MEDLINE | ID: mdl-26473944

RESUMO

In this study, C3N4/Zn(1-x)Cd(x)S (0 ≤ x ≤ 1) heterostructures with adjustment of the band gap were successfully prepared by calcination and a hydrothermal synthesis method. The photocatalytic properties of C3N4/Zn(1-x)Cd(x)S composite photocatalysts were evaluated by the photocatalytic degradation of RhB under visible light irradiation. The results showed that the combination of the two semiconductor photocatalysts (C3N4 and Zn(1-x)Cd(x)S) greatly enhanced the photocatalytic degradation efficiency of RhB compared to the pure C3N4 and Zn(1-x)Cd(x)S under visible light irradiation. Among them, the 0.1C3N4/Zn0.8Cd0.2S composite photocatalyst exhibited the highest photocatalytic activities with the degradation efficiency of RhB arriving to 97.9% within 90 min. The remarkable photocatalytic activity of the 0.1C3N4/Zn0.8Cd0.2S composite photocatalyst was mainly attributed to the appropriate band structure and the effective separation of photogenerated electron-hole pairs. Additionally, a possible basic mechanism of the composite semiconductor photocatalytic process was also discussed. Moreover, it was also investigated that O2(˙⁻) and h(+) were the main reactive oxidative species in this photocatalytic process of the degradation of RhB on the 0.1C3N4/Zn0.8Cd0.2S heterostructure photocatalyst.

10.
J Hazard Mater ; 192(1): 186-91, 2011 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-21664048

RESUMO

The Mo-doped Bi(2)WO(6) three-dimensional (3D) hierarchical microspheres from nanoplates have been synthesized by a hydrothermal route. The products were characterized in detail by multiform techniques: X-ray diffraction (XRD), energy-dispersive X-ray analysis (EDS), scanning electron microscopy (SEM), and UV-vis absorption spectrum. The results of the photocatalytic degradation of Rhodamine-B (RhB) in aqueous solution showed that molybdenum ions doping greatly improved the photocatalytic efficiency of Bi(2)WO(6) 3D hierarchical microspheres. The Mo-doped Bi(2)WO(6) microspheres with atomic ratio of Mo-W of 0.05 had the best activity in photodegradation of RhB in aqueous solution under 500 W Xe lamp light irradiation.


Assuntos
Bismuto/química , Catálise , Molibdênio/química , Óxidos/química , Fotoquímica , Tungstênio/química , Microscopia Eletrônica de Varredura , Microscopia Eletrônica de Transmissão , Microesferas
11.
J Nanosci Nanotechnol ; 11(3): 2501-5, 2011 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-21449413

RESUMO

In this paper, a green chemical synthetic route was developed to synthesize WO3 nanoparticles with an average size of 70 nm. The products were characterized in detail by multiform techniques: X-ray diffraction (XRD), energy-dispersive X-ray analysis (EDS), scanning electron microscopy (SEM), and transmission electron microscopy (TEM). The photoluminescence of the obtained WO3 nanoparticles was also investigated. The effects of the hydrothermal temperature on the crystalline phase and morphology of the products have been studied systematically. The photocatalytic activity of the samples was evaluated by photocatalytic decolorization of methylene blue (MB) aqueous solution. The electrocatalytic activity was characterized using voltammetric techniques. The results showed that the obtained WO3 nanoparticles have an excellent photocatalytic and electrocatalytic performance for the MB.


Assuntos
Cristalização/métodos , Química Verde/métodos , Azul de Metileno/química , Azul de Metileno/efeitos da radiação , Nanoestruturas/química , Nanoestruturas/ultraestrutura , Tungstênio/química , Catálise , Luz , Teste de Materiais , Conformação Molecular , Nanoestruturas/efeitos da radiação , Nanotecnologia/métodos , Tamanho da Partícula , Soluções , Propriedades de Superfície , Tungstênio/efeitos da radiação , Água/química
12.
J Nanosci Nanotechnol ; 10(10): 6739-43, 2010 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-21137789

RESUMO

In this paper, Ag/C nanocables were synthesized via a one-step simple hydrothermal route by using glucose as reducing agent and carbon source, AgNO3 as silver source. The products are characterized in detail by multiform techniques: X-ray diffraction, energy-dispersive X-ray analysis, scanning electron microscopy, transmission electron microscopy. The results show that the obtained products are coaxial nanocables with lengths of several micrometers, about 200-500 nm in diameter, and a surrounding sheath about 80-100 nm in thickness. Different products including carbonaceous nanotubes and nanocables with fragmentary Ag core were obtained by adjusting time of chemical etching.

13.
J Hazard Mater ; 179(1-3): 1122-7, 2010 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-20427124

RESUMO

The ZnWO(4) nanorods doped with cadmium ions have been successfully synthesized by a hydrothermal crystallization process. The products were characterized in detail by multiform techniques: X-ray diffraction (XRD), energy dispersive X-ray analysis (EDS), scanning electron microscopy (SEM), and transmission electron microscopy (TEM). The results of the photocatalytic degradation of rhodamine B (RhB) in aqueous solution showed that cadmium ions doping greatly improved the photocatalytic efficiency of ZnWO(4) nanorods. The Cd-doped ZnWO(4) nanorods with atomic ratio of Cd to Zn being 0.06 had the best activity in photo-degradation of RhB in aqueous solution under UV light irradiation, when the nanorods have prepared at pH 8.


Assuntos
Cádmio/química , Nanotubos , Compostos de Tungstênio/química , Compostos de Zinco/química , Catálise , Cristalização , Corantes Fluorescentes , Temperatura Alta , Microscopia Eletrônica de Varredura , Microscopia Eletrônica de Transmissão , Fotoquímica , Rodaminas , Compostos de Tungstênio/síntese química , Difração de Raios X , Compostos de Zinco/síntese química
14.
J Nanosci Nanotechnol ; 8(3): 1494-6, 2008 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-18468180

RESUMO

The alpha-MnO2 spherical assemblies were prepared via a facile hydrothermal approach in the presence of sodium dodecyl sulfate (SDS). The assembled nanostructures were composed of the MnO2 nanorods with 150-200 nm in width and several micrometers in length. The products were characterized by SEM, TEM and XRD. The electrochemical characterization was carried out by cyclic voltammetry, which indicated that the alpha-MnO2 spherical assemblies were of an excellent electrode material for supercapacitor.

15.
Acta Crystallogr Sect E Struct Rep Online ; 64(Pt 9): o1763, 2008 Aug 16.
Artigo em Inglês | MEDLINE | ID: mdl-21201745

RESUMO

In the title compound, C(13)H(28)N(2) (2+)·SO(4) (2-)·H(2)O, extensive hydrogen-bonding inter-actions between the protonated 4,4'-(propane-1,3-di-yl)dipiperidinium ions, the sulfate anions and the water mol-ecules lead to a three-dimensional pillared and layered structure with the 4,4'-(propane-1,3-di-yl)-dipiperidinium ions acting as the pillars.

16.
Acta Crystallogr Sect E Struct Rep Online ; 64(Pt 9): o1764, 2008 Aug 16.
Artigo em Inglês | MEDLINE | ID: mdl-21201746

RESUMO

In the title compound, C(6)H(14)N(2+)·C(8)H(4)O(4) (2-), the protonated 1,4-diazo-niabicyclo-[2.2.2]octane cations and the deprotonated terephthalate anions are alternately linked by N-H⋯O hydrogen bonds into chains.

17.
Acta Crystallogr C ; 63(Pt 11): m481-3, 2007 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-17989457

RESUMO

The title compound, [Zn(2)(C(16)H(12)O(6))(2)(C(12)H(8)N(2))(2)(H(2)O)(2)](n), consists of linear chains formed through 5-[4-(hydroxymethyl)benzyloxy]isophthalate (mabobdc) ligands linking five- and six-coordinated Zn(II) ions. The linear chains are linked into a bilayer network via O-H...O hydrogen bonds. Adjacent bilayer structures are further linked with each other via C-H...O hydrogen bonds and pi-pi and C-H...pi interactions to give a three-dimensional supramolecular framework. The results demonstrate the coordination and supramolecular chemistry of the mabobdc ligand.

SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA