Selective Photoelectrocatalytic Degradation of Recalcitrant Contaminant Driven by an n-P Heterojunction Nanoelectrode with Molecular Recognition Ability

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• 作者：Shouning Chai ; Guohua Zhao ; Ya-nan Zhang ; Yujing Wang ; Fuqiao Nong ; Mingfang Li ; Dongming Li
• 刊名：Environmental Science & Technology (ES&T)
• 出版年：2012
• 出版时间：September 18, 2012
• 年：2012
• 卷：46
• 期：18
• 页码：10182-10190
• 全文大小：522K
• 年卷期：v.46,no.18(September 18, 2012)
• ISSN：1520-5851

文摘

With in situ molecular imprinting technique, a novel nanoelectrode (MI, n-P)-TiO₂ with n-P heterojunction and molecular recognition ability was fabricated by liquid phase deposition at low temperature. Using bisphenol A (BPA) as template, the spindle-like TiO₂ particles 40鈥?0 nm in size compactly grew on the boron-doped diamond (BDD) substrate. Several spectroscopy measurements demonstrate that the BPA molecules were successfully imprinted on the TiO₂ matrix and numerous specific recognition sites to template were formed after calcination. The transient photocurrent response experiments have confirmed that the (MI, n-P)-TiO₂ nanoelectrode displays outstanding photoelectrocatalytic (PEC) activity and selectivity. The (MI, n-P)-TiO₂ is further employed in degrading the mixture containing BPA and interference 2-naphthol (2-NP). After 2 h, BPA removal reaches 97%, and corresponding kinetic constant is 1.76 h^鈥?, which is 4.6 times that of 2-NP removal even if 2-NP is much more concentrated. On the electrode without molecular imprint, the removal rate constants of BPA and 2-NP approximately equal, only about 0.5 h^鈥?. The results indicate that selective PEC oxidation can be realized readily on the (MI, n-P)-TiO₂ nanoelectrode due to the synergetic effects including strong recognition adsorption, formation of n-P heteojunction, and external electrostatic field. The effect of formation of n-P heterojunction on the enhanced PEC performances is also discussed.