北京大学学报(自然科学版) ›› 2016, Vol. 52 ›› Issue (6): 1141-1147.DOI: 10.13209/j.0479-8023.2016.108

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钛酸纳米管形成过程中不同水热反应阶段产物表征及其对Cd(Ⅱ)吸附的特性研究

蔡斌1,2, 王婷2,†   

  1. 1. 北京大学深圳研究生院环境与能源学院, 深圳 518055
    2. 北京大学环境工程系, 水沙教育部重点实验室, 北京 100871
  • 收稿日期:2015-05-26 修回日期:2015-06-02 出版日期:2016-11-20 发布日期:2016-11-20
  • 通讯作者: 王婷, E-mail: wang_ting(at)pku.edu.cn
  • 基金资助:
    深圳市科技研发资金(CXY201106290063A)资助

Characterization of Titanate Products with Different Formation Stages and Adsorption Characteristics of Cd(Ⅱ)

CAI Bin1, 2, WANG Ting2,†   

  1. 1. School of Environment and Energy, Peking University Shenzhen Graduate School, Shenzhen 518055
    2. Department of Environmental Engineering, Peking University, The Key Laboratory of Water and Sediment Sciences, Ministry of Education, Beijing 100871
  • Received:2015-05-26 Revised:2015-06-02 Online:2016-11-20 Published:2016-11-20
  • Contact: WANG Ting, E-mail: wang_ting(at)pku.edu.cn

摘要:

在以 P25 二氧化钛为钛源, 水热反应时间为1, 2, 3, 4天条件下, 合成钛酸纳米管(TNTs)形成过程中的4种产物, 采用XRD, SAXS和N2吸附/脱附等温线等手段进行表征。以Cd(Ⅱ)为代表污染物, 研究4种产物对Cd(Ⅱ)的吸附, 并着重分析4种产物的结构对其吸附能力的影响。粉末XRD结果表明, TNTs的4种产物均为单斜晶胞结构。SAXS和N2吸附/脱附表征证实, 水热法制备TNTs经历二氧化钛源结构解体→钛酸纳米管形成→管状结构解体的过程, TNTs-3d具有最为规整的管状形貌。吸附等温线结果表明, Langmuir-Freundlich模型能够更好地拟合吸附等温结果, 且Cd(Ⅱ)的吸附量大小顺序为TNTs-3d ≈ TNTs-1d > TNTs-4d > TNTs-2d。进一步的分析表明, 样品的回转半径、孔体积对吸附量影响较小, 而比表面积和平均孔径可能会显著影响吸附容量。

关键词: 钛酸纳米管, SAXS, 吸附, Langmuir-Freundlich 模型

Abstract:

Series of products with different formation stages of titanate nanotubes (TNTs) are synthesized, with the hydrothermal reaction time of 1, 2, 3, 4 days. XRD, SAXS and N2 adsorption/desorption have been chosen to detect the morphology and structure of various products. Afterwards, the adsorption behavior of Cd(Ⅱ) onto various products are also compared, and possible mechanism for the different adsorption capacities are detected based on their structures. XRD detection depictes that all products are monoclinic system. Results from SAXS and N2 adsorption/desorption suggeste that the formation processes of TNTs are the disintegration of TiO2→the formation of titanate nanotubes→the destruction of tubular structures. Among all products, TNTs-3d displayes the best defined structure. As for Cd(Ⅱ) adsorption, Langmuir-Freundlich model can better describe the adsorption isotherm, and the adsorption capacities rank as: TNTs-3d ≈ TNTs-1d > TNTs-4d > TNTs-2d. Further detection proves that gyration radius and pore volume play little role, while BET surface area and the average pore diameter possibly affect the adsorption capacity.

Key words: titanate nanotubes, SAXS, adsorption, Langmuir-Freundlich model

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