Yang Shaogui, Quan Xie, Li Xinyong, Sun Cheng
State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing, 210093, P.R. China.
Photochem Photobiol Sci. 2006 Sep;5(9):808-14. doi: 10.1039/b604077b. Epub 2006 Jun 26.
Taking pentachlorophenol (PCP) as a reference, we investigated the photoelectrocatalytic degradation of organic pollutants using a rutile nanotube-like TiO(2)/Ti film electrode. The nanotube-like TiO2 electrode was prepared by first oxidizing the surface of a titanium sheet to form rutile TiO2 and then treating it to form the tubular structure in NaOH aqueous solution. The occurrence of PCP degradation was indicated by the decrease in pH, concentration of PCP and TOC, and by the formation of chloride ions. The photoelectrochemical (PEC) efficiency of the nanotube-like TiO2/Ti electrode has been determined in terms of degradation of PCP and the incident photo-to-current conversion efficiency (IPCE). The experimental results showed that PCP could be degraded more efficiently by a photoelectrocatalytic process than by a photocatalytic or electrochemical oxidation alone. A significant photoelectrochemical synergetic effect was observed. The kinetic constant of PEC degradation of PCP using a nanotube-like TiO2 electrode was over 60% higher than that using a TiO2 film electrode. It is noted that chloride ion and hydrogen ion concentration increased with irradiation time in the PEC degradation of PCP; PCP was gradually mineralized and the complete minimization of PCP took more time than its degradation.
以五氯苯酚（PCP）为参照，我们使用金红石型纳米管状TiO₂/Ti薄膜电极研究了有机污染物的光电催化降解。通过先氧化钛片表面形成金红石型TiO₂，然后在氢氧化钠水溶液中处理使其形成管状结构，制备出纳米管状TiO₂电极。PCP降解的发生通过pH值、PCP浓度和总有机碳（TOC）的降低以及氯离子的形成来表明。基于PCP的降解和入射光电流转换效率（IPCE）测定了纳米管状TiO₂/Ti电极的光电化学（PEC）效率。实验结果表明，与单独的光催化或电化学氧化相比，PCP通过光电催化过程降解效率更高。观察到显著的光电化学协同效应。使用纳米管状TiO₂电极进行PCP的PEC降解的动力学常数比使用TiO₂薄膜电极时高出60%以上。值得注意的是，在PCP的PEC降解过程中，氯离子和氢离子浓度随照射时间增加；PCP逐渐矿化，PCP的完全矿化比其降解需要更多时间。
