难降解有机污染物与葡萄糖的光电催化协同氧化作用

The synergistic photoelectrocatalytic oxidation between refractory organic and glucose on TNA electrode

利用薄层反应器研究了典型的难降解有机污染物——三环癸胺在二氧化钛纳米管阵列电极表面的光电催化降解性能,重点考察了三环癸胺与葡萄糖的光电催化协同氧化作用.研究表明,三环癸胺作为一种化学性质稳定的化合物,在薄层反应器中难以在二氧化钛纳米管阵列电极光电催化中实现完全降解.在三环癸胺COD浓度50—400 mg.L-1条件下,其降解效率均低于30%,且随着三环癸胺浓度的增加降解效率下降.三环癸胺与葡萄糖之间存在着明显的光电催化协同氧化作用,且随着葡萄糖浓度的增加协同作用增强,当葡萄糖与三环癸胺浓度比值大于2时,可以实现三环癸胺的完全降解.在光电催化协同氧化过程中,三环癸胺与葡萄糖的降解并非同步进行,易降解的多羟基葡萄糖所产生的大量羟自由基,可能促进了三环癸胺或三环癸胺中间产物的氧化.该研究也为难降解的有机物的光电催化处理提出了一条新的途径.

The photoelectrochemical degradation performance of adamantine, a typical kind of refractory organics, especially the synergetic effect of photoelectrochemical oxidation between adamantine and glucose on the titania nanotube array （TNA） surface was reported by using a thin-layer reactor. The results showed that adamantine could not be mineralized completely in the thin-layer reactor due to its highly stable chemical properties. When adamantine concentration was ranged from 50 to 400 mg. L-1 , the degradation rate was lower than 30% and decreased with the increase of its concentration. However, in the presence of glucose, the adamantine could be thoroughly mineralized when the concentration ratio between glucose and adamantine was above 2. Also, the degradation orders of adamantine and glucose on TNA were not in synchronous. The reason for the synergetic effect of photoelectrochemical oxidation between adamantine and glucose on TNA can be attributable to the polyhydroxy structure of glucose which is able to generate a large quantity of hydroxyl radicals. This structural feature could result in the mineralization of adamantine and the intermediate products. The work provides a promising method for the photoelectrochemical degradation of the refractory organics.