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1.
Small ; 19(33): e2301280, 2023 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-37066783

RESUMO

Solar-driven reduction of CO2 emissions into high-value-added carbonaceous compounds has been recognized as a sustainable energy conversion way. The high-efficiency charge separation and effective activation are the critical issues in the process. The local plasma effect of metal and the vacancy of semiconductors in the metal-semiconductor heterostructure can solve this issue extensively. Herein, an oxygen vacancy photocatalyst containing uniform Ag nanoparticles (Ag-20@Nb2 O5- x ) is designed, which exhibits an excellent reduction performance and the CO yield can reach 59.13 µmol g-1 with high selectivity. The carrier migration is accelerated and the activation of CO2 is facilitated by the local surface plasmon effect and oxygen vacancy. Moreover, the photocatalytic CO2 reduction mechanism is revealed based on the density functional theory and in situ technology in detail. This work provides an in-depth understanding of the design of more ingenious metal-semiconductor photocatalysts to achieve more efficient charge transfer.

2.
Adv Mater ; 29(1)2017 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-27758002

RESUMO

One-pot electroless galvanic cell deposition of a 3D hierarchical semiconductor-metal-semiconductor interlaced nanoarray is demonstrated. The fabricated 3D photoanode deviates from the typical planar geometry, and aims to optimize the effective surface area for light harvesting and long-range charge transfer-collection pathways.

3.
Spectrochim Acta A Mol Biomol Spectrosc ; 130: 129-35, 2014 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-24769384

RESUMO

Metal-semiconductor compounds, such as Ag/AgX (X=Cl, Br, I), enable visible light absorption and separation of photogenerated electron-hole through surface plasmon resonance (SPR) effect. However, the electron-hole generated and separated by light are vulnerable in Ag/AgX phase because of the occurrence of secondary recombined. In order to more effectively utilize the SPR photocatalytic effect, nanoparticles are located in a matrix. In this article, Ag/AgCl nanoparticles were synthesized in montmorillonite (MMT) matrix using dispersion method and light irradiation. The structure, composition and optical properties of such material were investigated by transmission electron microscopy (TEM), UV-visible diffuse reflectance spectroscopy (UV-Vis DRS), X-ray diffraction (XRD) and FTIR. Powder X-ray diffraction showed intercalation of Ag/AgCl nanoparticles into the clay layers. The as-prepared plasmonic photocatalyst exhibited an enhanced and stable photoactivity for the degradation of methylene blue (MB) under visible light. The high activity was attributed to the surface plasmon resonance (SPR) exhibited by Ag nanoparticles on the surface of AgCl. The detection of reactive species by radical scavengers displays that O2- and OH- are the main reactive species for the degradation of MB under visible light irradiation. The studies showed that 20 min illumination under visible light can complete degradation of methylene blue (MB), and indicate a high stability of photocatalytic degradation. The mechanism of separation of the photo-generated electrons and holes at the Ag/AgCl-MMT nanocomposite was discussed.


Assuntos
Bentonita/química , Azul de Metileno/química , Nanocompostos/química , Compostos de Prata/química , Prata/química , Catálise , Elétrons , Concentração de Íons de Hidrogênio , Luz , Microscopia Eletrônica de Transmissão , Compostos Orgânicos/química , Fotoquímica , Fotólise , Espectrofotometria Ultravioleta , Espectroscopia de Infravermelho com Transformada de Fourier , Ressonância de Plasmônio de Superfície , Difração de Raios X
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