TiO_2纳米管阵列的制备及光催化活性

Preparation and photocatalytic activity of TiO_2 nanotubular arrays

采用阳极氧化法在钛基体上制备TiO_2纳米管阵列,并通过XRD、SEM对其结构和形貌进行表征.以有机染料亚甲基蓝为降解对象,研究其可见光下光催化性能,通过紫外-可见漫反射对其机理进行解释.结果表明,此方法制备的TiO_2纳米管阵列在可见光下具有良好的光催化活性,而一般的TiO_2仅在紫外光照射下具有光催化活性.550℃所制备的TiO_2纳米管阵列在可见光照射120min后,对亚甲基蓝的降解率可达到52%,这归结为所制备TiO_2纳米管阵列对可见光的吸收,以及高比表面积和高度有序性利于电子的传输,从而获得良好的可见光催化活性.

TiO_2 nanotubular arrays were prepared on Ti substrate through potentiostatic anodization.XRD and SEM were used to characterize the phase and morphology of the TiO_2 nanotubular arrays.The photocatalytic activity of as-prepared TiO_2 nanotubular arrays was evaluated by the degradation of methylene blue aqueous solution under visible light.And the photocatalytic mechanism was explored via the UV-Vis diffuse Reflection.The results display the prepared TiO_2 nanotubular arrays show excellent photocatalytic activity under visible light irradiation(λ>420 nm),however,the general TiO_2 has only photocatalytic activity under ultraviolet light irradiation.The degradation rate of methylene blue on the TiO_2 nanotubular arrays prepared at 550 ℃ can reach 52% after visible light irradiation for 120 min.The reason might be attributed to visible light observation of TiO_2 nanotubes,and the high specific surface area and highly orderly which could enhance the electron transmission,which lead to good visible-light photocatalytic activity.