Surface Tailoring for Controlled Photoelectrochemical Properties: Effect of Patterned TiO2 Microarrays
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- 作者：Da Chen ; Yanfang Gao ; Geng Wang ; Hao Zhang ; Wu Lu ; Jinghong Li
- 刊名：Journal of Physical Chemistry C
- 出版年：2007
- 出版时间：September 6, 2007
- 年：2007
- 卷：111
- 期：35
- 页码：13163 - 13169
- 全文大小：432K
- 年卷期：v.111,no.35(September 6, 2007)
- ISSN：1932-7455
文摘
In efforts to make use of unprecedented physical and chemical characteristics of titania (TiO2) nanomaterialsand investigate their innovative developments in microsystem applications, it is essential to affix them onsurfaces or arrange them in an organized network. In this work, a simple, fast, and cheap patterning techniquefor the fabrication of patterned TiO2 microarrays with different features is presented. As an alternative totypical pattern transfer techniques for microfabrication, this work employed a standard microcontact printing(
CP) process for the fabrication of patterned titania microarrays onto F-doping SnO2 (FTO) conductiveglass substrates. During the CP process, the titania precursor was used as the "ink" and transferred from apattern-featured poly(dimethylsiloxane) "stamp" onto the pretreated FTO substrate. Following the subsequentthermal oxidation, patterned TiO2 microarrays with different features (100, 200, and 400 m) were successfullyachieved. The surface properties and the photoelectrochemical properties of as-prepared patterned TiO2microarrays were investigated by scanning electron microscopy, X-ray diffraction, UV-vis absorptionspectroscopy, electrochemical impedance spectroscopy, Mott-Schottky spectroscopy, photocurrent actionspectroscopy, and photocatalytic degradation. It was demonstrated that these properties were dependent onthe feature size of the TiO2 patterns. For the patterned TiO2 thin film photoelectrodes with 100, 200, and 400m patterns, the generated peak photocurrent was ca. 5, 2, and 1 nA, and the photodegradation rate constantof methylene blue was found to be 1.747%, 1.415%, and 0.96% min-1, respectively. Clearly, with the decreaseof the feature size, the photocurrent action and photocatalytic ability of the patterned TiO2 thin film increased,which was due to the increased TiO2 surface area as well as the increased optical path length within thepatterned TiO2 thin film, resulting from multiple reflection of incident light. This work indicates that patternedTiO2 thin films are attractive systems for surface tailoring and also provide a novel method to effectivelycontrol the photoelectrochemical properties of nanostructured TiO2 thin films with promising applications inmicrosystem devices for solar energy conversion, photocatalysis, sensing, and so on.
CP) process for the fabrication of patterned titania microarrays onto F-doping SnO2 (FTO) conductiveglass substrates. During the CP process, the titania precursor was used as the "ink" and transferred from apattern-featured poly(dimethylsiloxane) "stamp" onto the pretreated FTO substrate. Following the subsequentthermal oxidation, patterned TiO2 microarrays with different features (100, 200, and 400 m) were successfullyachieved. The surface properties and the photoelectrochemical properties of as-prepared patterned TiO2microarrays were investigated by scanning electron microscopy, X-ray diffraction, UV-vis absorptionspectroscopy, electrochemical impedance spectroscopy, Mott-Schottky spectroscopy, photocurrent actionspectroscopy, and photocatalytic degradation. It was demonstrated that these properties were dependent onthe feature size of the TiO2 patterns. For the patterned TiO2 thin film photoelectrodes with 100, 200, and 400m patterns, the generated peak photocurrent was ca. 5, 2, and 1 nA, and the photodegradation rate constantof methylene blue was found to be 1.747%, 1.415%, and 0.96% min-1, respectively. Clearly, with the decreaseof the feature size, the photocurrent action and photocatalytic ability of the patterned TiO2 thin film increased,which was due to the increased TiO2 surface area as well as the increased optical path length within thepatterned TiO2 thin film, resulting from multiple reflection of incident light. This work indicates that patternedTiO2 thin films are attractive systems for surface tailoring and also provide a novel method to effectivelycontrol the photoelectrochemical properties of nanostructured TiO2 thin films with promising applications inmicrosystem devices for solar energy conversion, photocatalysis, sensing, and so on.