Department of Chemistry, Lakehead University, 955 Oliver Road, Thunder Bay, Ontario, P7B 5E1, Canada.
Electrochemical Technology Centre, Department of Chemistry, University of Guelph, 50 Stone Road East, Guelph, Ontario, N1G 2W1, Canada.
Chemosphere. 2018 Oct;209:182-190. doi: 10.1016/j.chemosphere.2018.06.042. Epub 2018 Jun 7.
In the present work, we report on a facile UV treatment approach for enhancing the electrocatalytic activity of TiO nanotubes. The TiO nanotubes were prepared using an anodization oxidation method by applying a voltage of 40 V for 8 h in a DMSO + 2% HF solution, and further treated under UV light irradiation. Compared with Pt and untreated TiO nanotubes, the UV treated electrode exhibited a superior electrocatalytic activity toward the oxidation of 4-chlorophenol (4-ClPh). The effects of current density and temperature on the electrochemical oxidation of the 4-ClPh were also systematically investigated. The high electrocatalytic activity of the UV treated TiO nanotubes was further confirmed by the electrochemical oxidation of other persistent organic pollutants including phenol, 2-, 3-, 4-nitrophenol, and 4-aminophenol. The total organic carbon (TOC) analysis revealed that over 90% 4-ClPh was removed when the UV treated TiO electrode was employed and the rate constant was 16 times faster than that of the untreated TiO electrode; whereas only 60% 4-ClPh was eliminated at the Pt electrode under the same conditions. This dramatically improved electrocatalytic activity might be attributed to the enhanced donor density, conductivity, and high overpotential for oxygen evolution. Our results demonstrated that the application of the UV treatment to the TiO nanotubes enhanced their electrochemical activity and energy consumption efficiency significantly, which is highly desirable for the abatement of persistent organic pollutants.
在本工作中，我们报道了一种简便的 UV 处理方法，用于增强 TiO 纳米管的电催化活性。TiO 纳米管通过在 DMSO+2%HF 溶液中施加 40 V 的电压 8 小时的阳极氧化氧化方法制备，并进一步在 UV 光照射下处理。与 Pt 和未经处理的 TiO 纳米管相比，UV 处理电极对 4-氯苯酚（4-ClPh）的氧化表现出优异的电催化活性。还系统研究了电流密度和温度对 4-ClPh 电化学氧化的影响。UV 处理 TiO 纳米管的高电催化活性还通过电化学氧化其他持久性有机污染物（包括苯酚、2-、3-、4-硝基苯酚和 4-氨基酚）得到了进一步证实。总有机碳（TOC）分析表明，当使用 UV 处理的 TiO 电极时，超过 90%的 4-ClPh 被去除，而速率常数比未处理的 TiO 电极快 16 倍；而在相同条件下，Pt 电极仅去除了 60%的 4-ClPh。这种电催化活性的显著提高可能归因于施主密度、电导率和析氧过电势的提高。我们的结果表明，将 UV 处理应用于 TiO 纳米管可显著提高其电化学活性和能量消耗效率，这对于消除持久性有机污染物是非常理想的。
