石墨烯修饰Y型TiO_2纳米管光电极制备及其对氨氮催化氧化性能

Reduced Graphene Oxide Modified Y-Branched TiO_2 Nanotubes Photoelectrode:Preparation and Photoelectrocatalytic Oxidation of Ammonia

采用三步阳极氧化法和一步循环伏安电沉积法制备了还原氧化石墨烯(rGO)修饰的Y型TiO_2纳米管(rGO/Y-TiO_2NTs)电极。通过场发射电子扫描显微镜(FESEM)、X射线能谱(EDS)、X射线衍射(XRD)、紫外可见漫反射光谱(UV-Vis DRS)及拉曼光谱(Raman)等对电极样品进行了表征。以rGO/Y-TiO_2NTs电极为光阳极,测试了不同循环伏安沉积圈数对电极光电流响应的影响,考察了在1.0 V偏压下电极对氨氮的光电催化氧化性能。结果表明,高度有序的Y-TiO_2NTs为锐钛矿型,具有大的比表面积,表面修饰平滑透明rGO薄膜后可显著提高其光电催化效率,沉积圈数为30时电极在30 min内对氨氮的光电催化氧化效率为95.9%。

The rGO/Y-TiO2 nanotubes （rGO/Y-TiO2NTs）electrodes with different rGO loading were fabricated by a three-step anodic oxidation, followed by a one-step cyclic voltammetric electrodeposition technique. Field emission scanning electron microscopy （FESEM）, X-ray energy dispersive spectrometry （EDS）, X-ray diffraction （XRD）, UV-Vis diffuse reflection spectrum （UV-Vis DRS）and Raman spectrum were used to characterize the morphology, element composition and crystal form of the samples. Photocurrent responses and the performance of photoelectrocatalytic （PEC）oxidation of ammonia were investigated under 1.0 V bias potential using rGO/Y-TiO2NTs electrodes prepared under different cyclic voltammetric cycle numbers. The results indicated that the highly ordered Y-TiO2NTs possessed the crystal form of anatase phases with high surface area. The smooth and transparent rGO film was electrodeposited on the surface of Y-TiO2NTs. The photoelectrocatalytic efficiency of ammonia using rGO/Y-TiO2NTs electrode was improved by the modification of rGO film, and reached 95.9% in 30 min when the electrodeposition cycle number was 30, which was 1.3 time higher than that of the pristine Y-TiO2NTs electrodes.