Br掺杂纳米多孔TiO2的制备及其吸附性能
来源期刊：中国有色金属学报2012年第12期
论文作者：张文莉 燕云 吕红艳 张福梅 蒋银花
文章页码：3439 - 3445
关键词：Br掺杂；二氧化钛；纳米多孔材料；吸附动力学；吸附热力学
Key words：Br doping; TiO2; nanoporous material; adsorption kinetics; adsorption thermodynamics
摘 要：以钛酸四丁酯为钛源，NH4Br为溴源，应用水热技术制备Br掺杂纳米多孔TiO2材料(Br/TiO2)。利用X射线衍射仪和场发射扫描电镜表征材料的结构和形貌，并从热力学和动力学角度研究Br/TiO2对阳离子蓝X-GRL的吸附行为。结果表明：Br掺杂有利于形成棒状交联的多孔结构，增强TiO2对阳离子蓝X-GRL的吸附性能，吸附效率为92.2%，是空白样品的1.56倍。动力学研究表明：该吸附行为符合准二级动力学模型，测得其表观活化能为14.551 kJ/mol，说明该吸附属于物理吸附。热力学研究表明：Br/TiO2对阳离子蓝X-GRL吸附自由能变为-8.343~-5.600 kJ/mol，吸附熵变为137.10 J/(K·mol)，吸附焓变为33.773 kJ/mol，该吸附过程是一个自发的吸热过程。
Abstract: Br-doped TiO2 nano porous materials (Br/TiO2) were prepared using NH4Br as the bromine precursor and tetrabutylorthotitanate as Ti source by the hydrothermal method. The structure and morphology of the prepared sample were characterized by X-ray diffraction (XRD) and field-emission scanning electronmicroscopy (FE-SEM). The kinetic and thermodynamic parameters for the absorption of cationic blue X-GRL in aqueous solution by Br/TiO2 were studied．The results show that Br doping favors to form the nano porous network structure composed of TiO2 nanorods, which helps to the absorption property of cationic blue X-GRL. The adsorption efficiency of Br/TiO2 is 92.2%, which is the 1.56 times of bare TiO2. The kinetics study results show that the pseudo-second-order kinetic model is well described for the adsorption of Br/TiO2 for cationic blue X-GRL. And the apparent activation energy is determined to be 14.551 kJ/mol. The thermodynamics study results show that the values of ΔGΘ are in the range of -8.343~-5.600 kJ/mol, and the values of ΔHΘ and ΔSΘ are 33.773 kJ/mol and 137.10 J/(K·mol), respectively. So, the adsorption process is endothermic and spontaneous.
张文莉，燕 云，吕红艳，张福梅，蒋银花
(江苏大学 化学化工学院，镇江 212013)
摘 要：以钛酸四丁酯为钛源，NH4Br为溴源，应用水热技术制备Br掺杂纳米多孔TiO2材料(Br/TiO2)。利用X射线衍射仪和场发射扫描电镜表征材料的结构和形貌，并从热力学和动力学角度研究Br/TiO2对阳离子蓝X-GRL的吸附行为。结果表明：Br掺杂有利于形成棒状交联的多孔结构，增强TiO2对阳离子蓝X-GRL的吸附性能，吸附效率为92.2%，是空白样品的1.56倍。动力学研究表明：该吸附行为符合准二级动力学模型，测得其表观活化能为14.551 kJ/mol，说明该吸附属于物理吸附。热力学研究表明：Br/TiO2对阳离子蓝X-GRL吸附自由能变为-8.343~-5.600 kJ/mol，吸附熵变为137.10 J/(K·mol)，吸附焓变为33.773 kJ/mol，该吸附过程是一个自发的吸热过程。
关键词：Br掺杂；二氧化钛；纳米多孔材料；吸附动力学；吸附热力学
ZHANG Wen-li, YAN Yun, LÜ Hong-yan, ZHANG Fu-mei, JIANG Yin-hua
(School of Chemistry and Chemical Engineering, Jiangsu University, Zhenjiang 212013, China)
Abstract:Br-doped TiO2 nano porous materials (Br/TiO2) were prepared using NH4Br as the bromine precursor and tetrabutylorthotitanate as Ti source by the hydrothermal method. The structure and morphology of the prepared sample were characterized by X-ray diffraction (XRD) and field-emission scanning electronmicroscopy (FE-SEM). The kinetic and thermodynamic parameters for the absorption of cationic blue X-GRL in aqueous solution by Br/TiO2 were studied．The results show that Br doping favors to form the nano porous network structure composed of TiO2 nanorods, which helps to the absorption property of cationic blue X-GRL. The adsorption efficiency of Br/TiO2 is 92.2%, which is the 1.56 times of bare TiO2. The kinetics study results show that the pseudo-second-order kinetic model is well described for the adsorption of Br/TiO2 for cationic blue X-GRL. And the apparent activation energy is determined to be 14.551 kJ/mol. The thermodynamics study results show that the values of ΔGΘ are in the range of -8.343~-5.600 kJ/mol, and the values of ΔHΘ and ΔSΘ are 33.773 kJ/mol and 137.10 J/(K·mol), respectively. So, the adsorption process is endothermic and spontaneous.
Key words:Br doping; TiO2; nanoporous material; adsorption kinetics; adsorption thermodynamics
