硝酸改性活性炭纤维负载TiO_2及其催化降解甲苯性能

Toluene Photocatalytic Degradation on TiO_2 Loaded on Nitrate-Modified Activated Carbon Fiber

将TiO2负载于经硝酸改性的活性炭纤维(ACF)上得到TiO2/ACF复合催化剂,采用扫描电镜(SEM)、X射线光电子能谱(XPS)、紫外激光拉曼光谱(Raman)和X射线衍射(XRD)等手段研究其形貌,并考察环境湿度、ACF硝化强度和TiO2负载量对甲苯光催化氧化降解的影响。结果表明:经硝酸改性的ACF表面富含含氧基团,能使TiO2在其表面均匀分布,从而使甲苯转化率提高近3.5倍;随环境湿度上升,甲苯转化率先上升后下降,主要是因为湿度上升,吸水量上升,导致甲苯吸附量下降;ACF硝化强度增大,导致催化剂吸水能力增强,从而提高甲苯转化率;TiO2负载量上升导致ACF表面TiO2颗粒形貌改变,使甲苯转化率先上升后下降。

TiO2/ACF catalysts were synthesized by depositing TiO2 on activated carbon fiber （ACF） modified by nitric acid. The physical properties were characterized by X-ray diffraction spectrum （XRD）, scanning electronic microscopy （SEM）, Raman Spectrum and X-ray photoelectron spectroscopy （XPS）. The effects of humidity, nitrification extent of ACF, and TiO2 loading on toluene photocatalytic degradation were investigated. The results showed that nitrification introduced rich oxygen-containing groups into ACF surface, which could lead to a more uniform TiO2 distribution and about 3.5 fold of toluene conversion. With the increase of humidity, the toluene conversion first increased then decreased. This was due to the fact that a high humidity resulted in a high water adsorption amount on the catalyst, therefore, reducing the toluene adsorption capacity. With the increase of nitrification extent of ACF, the toluene conversion increased due to the enhanced water adsorption capacity. With the increase of TiO2 loading, the toluene conversion first increased and then decreased too, because a high TiO2 loading changed the particle morphology on the catalyst surface.