Browsing by Author "Ke, Tsung-Ying"

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{110}-exposed rutile titanium dioxide nanorods in photocatalytic performance
(2009)
Ke, Tsung-Ying
;
Peng, Chih-Wei
;
Lee, Chi-Young
;
Chiu, Hsin-Tien
;
Sheu, Hwo-Shuenn
Single crystalline rutile TiO(2) nanorods were prepared by reacting sodium titanate with hydrochloric acid. The proposed formation mechanism involves a growth pathway. The growth proceeds along [001], and the circumferential faces are {110}, which are identified as the photoactive faces of rutile titanium dioxide. Both the heterogeneous ( photocatalyst only) and the combined heterogeneous/homogeneous (photocatalyst and H(2)O(2)) photocatalytic performances support its activity. The mechanism of formation and photocatalytic property are extensively studied.
Growth of polycrystalline tubular silicon carbide Yajima-type reaction at the vapor-solid interface
(2007-08-07)
Wang, Chia-Hsin
;
Lin, Huang-Kai
;
Ke, Tsung-Ying
;
Palathinkal, Thomas-Joseph
;
Tai, Nyan-Hwa
Polycrystalline tubular SiC on Si is prepared by reacting MeSiHCl2 vapor and Ca thin film on Si at 773-923 K followed by heat treatment at 1273 K. The reaction is a solvent-free Yajima-type process taking place at the vapor-solid interface. The products phase-segregate into a cable-like radial heterostructure composed of a core of CaCl2 and a shell of SiCxHy. After removal of the CaCl2 core, the layer of polycrystalline SiC tubes on Si can emit electrons at a low applied field of 2.5 V/mu m with a current of 10 mu A/cm(2).
Photo-induced nucleation of rutile nanorods-an ignored parameter in crystallization
(2011)
Ke, Tsung-Ying
;
Chen, Po-Chin
;
Yang, Min-Han
;
Chiu, Hsin-Tien
;
Lee, Chi-Young
This work presents a surfactant-free and economical sol-gel method to synthesize multi-branched rutile TiO(2) nano-trees. Simple illumination by incandescent light during synthesis causes numerous branches to grow from the sides of nanorods, this process is accompanied by hydroxylation of the crystal surface. A {101} twin is demonstrated to connect the trunk to the branches. The extents of branching and surface hydroxylation are controlled by either photo-illumination or the addition of an exciton scavenger (H(2)O(2)). The relationship between the quantity of the branches and the excitons can be elucidated by considering photo-induced defects.
Photocatalysis by Electron Transfer between Different-sized Anatases
(2010-06-15)
Ke, Tsung-Ying
;
Lee, Chi-Young
;
Chiu, Hsin-Tien
;
應用化學系
;
Department of Applied Chemistry
In the solution state, photocatalysis of micro- and nano-sized anatases can be optimized at flat band and in a high pH solution, respectively. Furthermore, a remarkable photocatalyst that can be adopted over a wide range of pH values was produced by mixing commercial micro- and nano-sized anatases. Mixing causes the electron transfer between the identical phase but different-sized TiO(2) particles, subsequently separating the electrons and holes, as well as greatly facilitating photocatalysis. As is well known, the commercially available photocatalyst P25, a mixture of anatase and rutile, achieves a superior photocatalytic performance from pH 3 to 10, owing to the electron transfer between the various phases. This study elucidates these mixed photocatalysts, P25 and mixture of micro and nano-sized anatases. Crown Copyright (C) Published by Elsevier B.V. All rights reserved.
Sodium niobate nanowire and its piezoelectricity
(2008-06-19)
Ke, Tsung-Ying
;
Chen, Hsiang-An
;
Sheu, Hwo-Shuenn
;
Yeh, Jien-Wei
;
Lin, Heh-Nan
Nanowires of crystalline orthorhombic sodium niobate (NaNbO3) with diameters of approximately 100 nm and lengths of several to hundreds of microns, as well as cubes with edges of lengths of hundreds of nanometers were obtained by reacting niobium oxide (Nb2O5) with 10 and 12.5 M NaOH solutions, respectively. The microstructures of the synthesized wiry and cubic piezoelectric materials were investigated, and the details of the reactions were elucidated as well. The piezoelectricity of individual NaNbO3 (Pbma) nanowires was confirmed by piezoresponse force microscopy, and an effective piezoelectric coefficient along the vertical direction of around a few pm/V was obtained. To our knowledge, the present work is the first report of the preparation of NaNbO3 nanowires as well as the determination of piezoelectricity.