Piezopotential-Induced Schottky Behavior of Zn1−xSnO3 Nanowire Arrays and Piezophotocatalytic Applications

详细信息    查看全文

• 作者：Ya-Ting Wang and Kao-Shuo Chang
• 刊名：Journal of the American Ceramic Society
• 出版年：2016
• 出版时间：August 2016
• 年：2016
• 卷：99
• 期：8
• 页码：2593-2600
• 全文大小：1911K
• ISSN：1551-2916

文摘

This article presents the piezotronic- and piezophototronic effect-enhanced photocatalysis (piezophotocatalysis) of Zn_1−xSnO₃ (ZTO) nanowires fabricated through a two-step hydrothermal reaction. The highlights of this research include (1) tailoring hydrothermal synthesis parameters to obtain well-aligned LN-type single-crystalline ZTO nanowire arrays; (2) exploring the piezopotential-driven piezotronic and piezophototronic effects of ZTO nanowires; (3) identifying Schottky barrier height variations; and (4) exploiting synergistic piezophotocatalysis for decomposing methylene blue (MB). Transmission electron microscopy, electron probe energy-dispersive spectroscopy, and X-ray photoelectron spectroscopy analyses reveal highly crystalline Zn-deficient ZTO nanowires. The band gap is estimated to be approximately 3.8 eV. The ZTO nanowires exhibit piezopotential-modulated piezotronic and piezophototronic effects. The corresponding Schottky barrier height variation is calculated using thermionic emission-diffusion theory. The calculated photodegradation rate constant k of the sample, under pressure from ultrasonic vibration and a piece of glass, is approximately 1.5 × 10⁻² min⁻¹, approximately four times higher than that of ZTO nanowires in the absence of stress. The observed synergistic piezophotocatalysis is attributed to (1) band bending of ZTO nanowires; (2) application of alternating ultrasonic vibration; (3) MB mass transfer enhancement; and (4) abundant active reaction sites generated from ZTO nanowire surface sweeping.