物理化学学报2012，Vol.28Issue(9)：2183-2190,8.DOI:10.3866/PKU.WHXB201206072
α-Fe2O3/SiO2纳米颗粒混合体系表面的酸碱性质及其对重金属离子的吸附行为
Acid-Base Properties and Adsorption Behaviors of Heavy Metal Ions at the Surface of α-Fe2O3/SiO2 Nano-Mixed System
摘要
Abstract
α-Fe2O3 and SiO2 were prepared from ferric nitrate and tetraethyl orthosilicate (TEOS) using a sol-gel method and templates. The samples were characterized by powder X-ray diffraction (XRD) and N2 adsorption-desorption methods. The surface acid-base properties of α-Fe2O3/SiO2 nano-mixed system were determined by potentiometric titration, and the adsorption behaviors of heavy metal ions on the solid surface of α-Fe2O3/SiO2 nano-mixed system were studied at different pH values. The surface acid-base reaction equilibrium constants of the nano-mixed system were calculated from the results using WinSGW software to be ≡XOH≒≡XO-+H+ (IgK=-8.20±0.15). The calculated result reveals that the deprotonation surface of the cr-Fe2C＞3/Si02 nano-mixed system is different from the surfaces of α-Fe2O3/SiO2/γ-AI2O3, α-Fe2O3/γ-AI2O3 and SiO2/γ-Al2O3 nano-mixed systems where surface protonation and deprotonation occur at the same time. Based on this result, the surface complexation constants of Cu2+ Pb2+, Zn2+ on the surface of α-Fe2O3/SiO2 mixed systems were simulated respectively as follows: ≡XOH + M2 + ≒ ≡XOM +H+, [IgK=-3.1, -3.6, -3.8 (M=Cu, Pb, Zn)]; ≡XOH+M2++H2O≒≡XOMOH+2H+, [IgK=-8.8, -8.0, -10.5 (M=Cu, Pb, Zn)].关键词
α-Fe2O3/SiO2/表面酸碱性质/吸附/重金属离子/组分分布Key words
α-Fe2O3/SiO2/ Surface acid-base property/ Adsorption/ Heavy metal ion/ Speciation distribution分类
化学化工引用本文复制引用
孙和云,樊佳妮,黄佩佩,孙中溪..α-Fe2O3/SiO2纳米颗粒混合体系表面的酸碱性质及其对重金属离子的吸附行为[J].物理化学学报,2012,28(9):2183-2190,8.基金项目
国家自然科学基金(50874052,20677022)和国家重点基础研究发展规划项目(2011CB933700)资助 （50874052,20677022）
