Efficient photocatalytic degradation of acid orange 7 over N-doped ordered mesoporous titania on carbon fibers under visible-light irradiation based on three synergistic effects
Efficient photocatalytic degradation of acid orange 7 over N-doped ordered mesoporous titania on carbon fibers under visible-light irradiation based on three synergistic effects
复制标题
基于三种协同效应的氮掺杂碳纤维有序介孔二氧化钛在可见光照射下高效光催化降解酸性橙7
DOI：
10.1016/j.apcata.2015.01.050
复制
发表时间：
2016-08-25
影响因子：
5.5
通讯作者：
Liu, Chen
中科院分区：
文献类型：
--
作者：
Li, Youji;Li, Ming;Liu, Chen
采用液晶模板法（LCT）和超临界沉积法制备了碳纤维负载氮掺杂有序介孔二氧化钛（NOMT/CFs）。通过X射线衍射分析、扫描电子显微镜和透射电子显微镜、X射线光电子能谱、N-2吸附、UV/维斯漫反射分光光度计和光致发光等手段对NOMT/CFs产物进行了表征。在可见光照射下，对所得产物降解酸性橙子7（AO 7）溶液的光活性进行了评价。NOMT/CFs的光催化机理涉及三个协同效应，即TiO 2作为电子/空穴发生器，其有序的介观结构促进电子-空穴分离，N掺杂增强可见光吸附，CFs用于将污染物集中在活性中心周围，有利于电子转移，便于回收。利用气相色谱和质谱分析了AO 7转化过程中产生的中间产物，提出了初步的分解途径。催化剂的量，pH值，和初始AO 7浓度的影响已被检查作为操作参数。光催化反应遵循伪一级动力学，并讨论了在一个修改后的Langmuir-Hinshelwood模型。(C)2016爱思唯尔B. V.保留所有权利。
N-Doped ordered mesoporous titania on carbon fibers (NOMT/CFs) has been prepared by a liquid-crystal template (LCT) method with the aid of supercritical deposition. The NOMT/CFs product has been characterized by X-ray diffraction analysis, scanning electron and transmission electron microscopies, X-ray photoelectron spectroscopy, N-2 sorption, UV/Vis diffuse reflectance spectrophotometry, and photoluminescence. The photoactivity of the obtained product in the degradation of acid orange 7 (AO7) solution under visible-light irradiation has been evaluated. A photocatalytic mechanism involving three synergistic effects of NOMT/CFs is proposed, whereby the titania acts as an electron/hole generator with its ordered mesostructure facilitating electron-hole separation, N-doping enhances visible-light adsorption, and the CFs serve to concentrate the pollutant around the active sites, favor electron transfer, and facilitate convenient recycling. Gas chromatography and mass spectrometry have been used to analyze the intermediates generated in the conversion of AO7, allowing a tentative decomposition pathway to be proposed. The effects of catalyst amount, pH, and initial AO7 concentration have been examined as operational parameters. The photocatalytic reactions follow pseudo-first-order kinetics and are discussed in terms of a modified Langmuir-Hinshelwood model. (C) 2016 Elsevier B.V. All rights reserved.