Browsing by Author "Chan, Kuei-Lin"

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Considerable humidity response of a well-aligned SOMS micro-wire flexible sensor by moisture-induced releasing of trapped electrons
(2017-09-07)
Chan, Kuei-Lin
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Yang, Min-Han
;
Chiu, Hsin-Tien
;
Lee, Chi-Young
;
應用化學系
Sandia Octahedral Molecular Sieves micro-wires (SOMS MWs) that exhibit ultra-high response to moisture and a short response time can be produced easily in an environmentally friendly mass production process. They are excellent candidate materials for use in humidity sensors. SOMS MWs were synthesized using niobium pentoxide as a precursor in concentrated sodium hydroxide solution. To fabricate humidity-sensing devices, electrophoresis was utilized to align the SOMS MWs on a polyethylene terephthalate (PET) substrate. The degree of alignment of SOMS MWs can be tuned by controlling the electric field during electrophoresis. Both well-aligned SOMS MWs (S-1.00) and randomly distributed SOMS MWs (S-0.00) exhibit maximum sensitivities to humidity (RRH/RDRY) of almost 10(4) and 10(7) respectively, and both exhibit short response times (34 and 38 s) and recovery times (7 and 10 s); these MWs outperform metal oxide ceramic-based materials in sensing humidity. Furthermore, the humidity response of S-1.00 exceeds that of S-0.00 by three orders of magnitude, and this result cannot be explained with reference to the Grotthuss mechanism. Therefore, the moisture-induced carriers from trapped electrons contribute significantly to the humidity response of SOMS MWs. In addition, with outstanding humidity sensing-performance under extreme bending conditions and superior durability after being bent hundreds of times, the well-aligned SOMS MW sensor is a favorable candidate for emerging multifunctional electronic-skin.
Outstanding antibacterial performance of bipyramidal anatase TiO2 with {101}-exposed facets
(2017-04-02)
Chan, Kuei-Lin
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Lee, Chi-Young
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Chiu, Hsin-Tien
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Chen, Jui-Yi
;
Li, Cheng-Yu
Photocatalytic performance of bipyramidal anatase TiO2 toward the degradation organic dyes and its catalyst poisoning effect
(1970-01-01)
Chan, Kuei-Lin
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Lin, Wei-Hsiang
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Chen, Fu-Jung
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Yang, Min-Han
;
Jiang, Cheng-Han
It has been reported that bipyramidal anatase TiO2 with {101}-exposed facets (AT170) results in outstanding photocatalytic performance. However, its activity decayed significantly and comparatively lower than that of commercial P25 after 20 min. Further studies and calculations showed that the methylene blue (MB) degradation rate constants for AT170 were time dependent and decrease of k values with time. Besides, the results of XPS, EA and TEM could clearly elucidate that the active sites of catalysts were blocked by the carbon buildup and covered on the surface creating the metal-carbon bonding on the catalysts. These observation strongly implied the existence of the poisoning effect of AT170 during photocatalytic processes. Also, the surface area values of P25 and AT170 were found to be 46.83 and 3.56 m(2)/g respectively. It was suggested that the catalyst poisoning effect could be prevented or controlled by increasing the surface area of the catalyst. Besides of surface area, zeta potential was also found to be served as the important factor determining the photocatalytic performance toward organic dyes due to the attraction/repulsion of electrostatic interaction. The zeta potential values of P25 and AT170 were found to be - 3.8 and - 32.9 mV respectively, which can adsorb cationic MB dyes on the negative charged surface through attraction of electrostatic interaction successively enhancing the degradation performance. It strongly indicates that both surface area and zeta potential play vital roles in photocatalytic degradation toward organic dyes and affect the rate constants.
Porous titanium oxynitride sheets as electrochemical electrodes for energy storage
(2014)
Chen, Ting-Ting
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Liu, Hsiao-Ping
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Wei, Yen-Ju
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Chang, I-Chun
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Yang, Min-Han
A flexible, porous TiOxNy sheet consisting of numerous conductive fibers was synthesized by nitridation of titanate and further used as an electrochemical electrode. The high surface area and mixed-oxidation state of titanium make TiOxNy sheets to be promising candidates for a good supercapacitor.
Size tunable submicro/micro TiO2-related spheres synthesized by sol-gel process and the applications
(2017-04-02)
Chen, Yi Hsuan
;
Chan, Kuei-Lin
;
Chiu, Hsin-Tien
;
Lee, Chi-Young
;
應用化學系