TiO₂基超疏水表面的制备及光催化润湿性转换

Preparation and photocatalytic wettability conversion of TiO2-based superhydrophobic surfaces.

作者信息

Zhang Xintong, Jin Ming, Liu Zhaoyue, Nishimoto Shunsuke, Saito Hidenori, Murakami Taketoshi, Fujishima Akira

机构信息

Kanagawa Academy of Science and Technology, KSP Building West 614, 3-2-1 Sakado, Kawasaki, Kanagawa 213-0012, Japan.

出版信息

Langmuir. 2006 Nov 7;22(23):9477-9. doi: 10.1021/la0618869.

DOI:10.1021/la0618869

PMID:17073465

Abstract

We present here a facile method for the preparation of TiO2-based superhydrophobic surfaces. It consists of two steps: (1) roughening of the TiO2 surface with a rf (radio frequency) plasma with CF4 as an etchant and (2) modification of the roughened TiO2 surface with an octadodecylphosphonic acid (ODP) monolayer. Plasma etching caused the thinning of the TiO2 film but at the same time enhanced its surface roughness. A discontinuous wedgelike surface microtexture was formed after etching for 30 s, which, after modification with a monolayer of ODP, showed Cassie-type water super-repellency with a contact angle (CA) hysteresis smaller than 2 degrees . The state of water super-repellency (water CA >165 degrees) could be converted to the state of superhydrophilicity (water CA approximately 0 degrees) by means of ultraviolet (UV) illumination as a result of the photocatalytic decomposition of the ODP monolayer by TiO2. Readsorption of ODP molecules leads directly to the recovery of water super-repellency.

摘要

我们在此展示一种制备基于TiO₂的超疏水表面的简便方法。它包括两个步骤：（1）以CF₄作为蚀刻剂，通过射频（rf）等离子体使TiO₂表面粗糙化；（2）用十二烷基膦酸（ODP）单分子层对粗糙化的TiO₂表面进行改性。等离子体蚀刻导致TiO₂薄膜变薄，但同时提高了其表面粗糙度。蚀刻30秒后形成了不连续的楔形表面微观结构，在用ODP单分子层改性后，表现出Cassie型水超疏性，接触角（CA）滞后小于2度。由于TiO₂对ODP单分子层的光催化分解，通过紫外线（UV）照射，水超疏性状态（水接触角>165度）可转变为超亲水性状态（水接触角约为0度）。ODP分子的重新吸附直接导致水超疏性的恢复。