Preparation of titania nanotubes and their environmental applications as electrode
Preparation of titania nanotubes and their environmental applications as electrode
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DOI：
10.1021/es048684o
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发表时间：
2005-05-15
影响因子：
11.4
通讯作者：
Zhao, HM
中科院分区：
文献类型：
--
作者：
Quan, X;Yang, SG;Zhao, HM
以0.2wt%氢氟酸为支持电解液，采用直接阳极氧化法在钛板上成功制备了二氧化钛纳米管。这些纳米管大小一致，排列良好，形成高密度阵列。它们看起来像霍尼韦尔，结构类似于通过相同技术获得的多孔氧化铝。X-射线衍射仪确定了二氧化钛的锐钛矿相。紫外可见吸收光谱发生了显著的蓝移。推测了纳米管新颖、简单、直接生长的机理。为了研究其在环境中的应用潜力，采用光电催化(PEC)方法对水溶液中的五氯苯酚(PCP)进行了降解，并与电化学法(EP)和光催化(PC)进行了比较。观察到显著的光电化学协同效应。纳米管电极上PEC降解五氯苯酚的动力学常数比薄膜电极上的高86.5%。在相同的条件下，采用溶胶-凝胶法制备的二氧化钛薄膜电极在4h内可使二氧化钛纳米管电极对PCP的总有机碳去除70%，而对50%的总有机碳去除效果较差。
Titanium oxide nanotubes were successfully grown from a titanium plate by direct anodic oxidation with 0.2 wt % hydrofluoric acid being the supporting electrolyte. These nanotubes are of uniform size and are well-aligned into high-density arrays. They look like honeywell with the structure similar to that of porous alumina obtained by the same technique. TiO2 anatase phase was identified by X-ray diffraction. Significant blue-shift in the spectrum of UV-vis absorption was observed. The mechanism of the novel, simple, and direct growth of the nanotubes was postulated. To investigate their potentials in environmental applications, degradation of pentachlorophenol (PCP) in aqueous solution was carried out using photoelectrocatalytic (PEC) processes, comparing with electrochemical process (EP) and photocatalytic (PC). A significant photoelectrochemical synergetic effect was observed. The kinetic constant of PEC degradation of PCP using TiO2 nanotubes electrode was 86.5% higher than that using TiO2 film electrode. In degrading PCP, 70% of TOC was removed using the TiO2 nanotubes electrode against 50% removed using TiO2 film electrode formed by sol-gel method in 4 h under similar conditions.