Synthesis, characterization, and photocatalytic activity of porous La-N-co-doped TiO₂ nanotubes for gaseous chlorobenzene oxidation

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• 作者：Zhuowei Cheng ; Zhiqi Gu ; Jianmeng Chen ; ^{jchen@zjut.edu.cn" class="auth_mail" title="E-mail the corresponding author} ; Jianming Yu ; Lingjun Zhou
• 关键词：Photocatalysis ; La/N&ndash ; TiO2 ; Chlorobenzene ; Conversion efficiency ; Kinetic analysis
• 刊名：Journal of Environmental Sciences
• 出版年：2016
• 出版时间：August 2016
• 年：2016
• 卷：46
• 期：Complete
• 页码：203-213
• 全文大小：1042 K

文摘

The photocatalytic oxidation of gaseous chlorobenzene (CB) by the 365 nm-induced photocatalyst La/N–TiO₂, synthesized via a sol–gel and hydrothermal method, was evaluated. Response surface methodology (RSM) was used to model and optimize the conditions for synthesis of the photocatalyst. The optimal photocatalyst was 1.2La/0.5N–TiO₂ (0.5) and the effects of La/N on crystalline structure, particle morphology, surface element content, and other structural characteristics were investigated by XRD (X-ray diffraction), TEM (Transmission Electron Microscopy), FTIR (Fourier transform infrared spectroscopy), UV–vis (Ultraviolet–visible spectroscopy), and BET (Brunauer Emmett Teller). Greater surface area and smaller particle size were produced with the co-doped TiO₂ nanotubes than with reference TiO₂. The removal of CB was effective when performed using the synthesized photocatalyst, though it was less efficient at higher initial CB concentrations. Various modified Langmuir-Hinshelwood kinetic models involving the adsorption of chlorobenzene and water on different active sites were evaluated. Fitting results suggested that competitive adsorption caused by water molecules could not be neglected, especially for environments with high relative humidity. The reaction intermediates found after GC–MS (Gas chromatography–mass spectrometry) analysis indicated that most were soluble, low-toxicity, or both. The results demonstrated that the prepared photocatalyst had high activity for VOC (volatile organic compounds) conversion and may be used as a pretreatment prior to biopurification.