利用仿生合成的方法在温和条件下制备了微米铜粉/纳米TiO2复合粒子. 选择有机胺对Cu粉进行表面处理, XPS分析表明有机胺通过N原子与表面Cu2+络合形成功能层, 在Cu粉表面引入 NH2和 OH等功能基团, 对比实验证实功能基团能够诱导无机氧化物的仿生沉积. XRD结果表明铜粉表面包覆的纳米TiO2呈现锐钛矿晶型, 漫反射光谱(DRS)分析表明, Cu粉经过有机胺处理后在716.5nm处出现了由Cu2+离子与N配位产生的弱吸收. 复合粒子的光吸收性能介于TiO2和Cu粉之间, Cu负载后样品的光吸收阀值从397.5nm红移至448.9nm, 红移的原因可归于Cu负载后TiO2导带下出现新能级, 光生电子经过这些中间能级发生跃迁, 所需激发能量降低至可见光范围. 448.9nm处吸收边的存在表明复合粒子具备可见光催化活性.
Micron size Cu/nanoTiO2 composite particles were prepared in ambient conditions by bioinspired method. The surfaces of Cu particles were modified by a kind of amine, and the analysis of XPS indicated that the functional layer containing -NH2 and -OH groups was formed on the surface of Cu particles through the coordination of nitrogen in the amine to Cu2+. Comparative experiment confirmed that -NH2 and -OH groups induced the biomineralization of nano-TiO2 on the Cu surfaces. XRD result showed that TiO2 of anatase type was deposited on the surfaces of Cu particles. Results of diffuse reflectance spectra (DRS) showed that a weak absorption at 716.5nm occurred after Cu particles were modified by the amine, which indicated the coordination of N to Cu2+. The photoabsorbance of Cu/nanoTiO2 composite particles was between the photo-absorbance of TiO2 and that of Cu. The optical absorption edge of the particles was extended from 397.5nm to about 448.9nm after Cu loading, because Cu loading introduces new mid gap level below the conduction band of TiO2, and in this way the electron can be excited by visible light through the level. The absorption edge at 448.9nm indicated that Cu/nano-TiO2 composite particles had the visible light catalytic activity.
[1] 刘会景, 柏 源, 孙红旗, 等(LIU Hui-Jing, et al). 掺杂基团对氮改性TiO2紫外光催化活性影响的机理研究. 无机材料学报(Journal of Inorganic Materials), 2009, 24(3):443-447.
[2]Lim S H, Phonthammachai N, Pramana S S, et al. Simple route to monodispersed silicatitania coreshell photocatalysts. Langmuir, 2008, 24(12):6226-6231.
[3]Ao Y H, Xu J J, Fu D G, et al. Low temperature preparation of anatase TiO2-coated activated carbon. Colloids and Surfaces A: Physicochem. Eng. Aspects, 2008, 312(2/3):125130.
[4]Woan K, Pyrgiotakis G, Sigmund W. Photocatalytic carbonnanotubeTiO2 composites. Advanced Materials, 2009, 21(1):1-7.
[5]梅长松, 钟顺和, 肖秀芬. Cu/V2O5-TiO2的结构、光吸收性能与催化反应性能研究. 功能材料, 2005, 36(2):256-259.
[6]徐林林, 唐艳茹. 仿生物矿化过程合成无机/有机复合体研究. 长春师范学院学报(自然科学版), 2007, 26(1):56-57.
[7]蔡国斌, 万 勇, 俞书宏(CAI Guo-Bin, et al). 受生物启发模拟合成生物矿物材料及其机理研究进展. 无机化学学报(Chinese Journal of Inorganic Chemistry), 2008, 24(5):673-683.
[8]Copello G J, Varela F, Martinez Vivot R, et al. Immobilized chitosan as biosorbent for the removal of Cd(Ⅱ), Cr(Ⅲ) and Cr(Ⅵ) from aqueous solutions. Bioresource Technology, 2008, 99(14):6538-6544.
[9]Becker T, Schlaak M, Strasdeit H. Adsorption of nickel(Ⅱ), zinc(Ⅱ) and cadmium(Ⅱ) by new chitosan derivatives. Reactive & Functional Polymers, 2000, 44(3):289-298.
[10]闫 军, 杜仕国, 崔海萍, 等(YAN Jun, et al). 涂覆Mannich碱对Cu粉抗氧化性能的影响. 金属学报(Acta Metallurgica Sinica), 2007, 43(4):388-392.
[11]Sagiv J. Organized monolayers by adsorption. 1. Formation and structure of oleophobic mixed monolayers on solid surfaces. Journal of the American Chemical Society, 1980, 102(1):92-98.
[12]Sá J, Agüera C A, Gross S. et al. Photocatalytic nitrate reduction over metal modifed TiO2. Applied Catalysis B: Environmental, 2009, 85(3/4):192-200.
[13]Yang R N, Li C Y, Liu Y F. et al. Synthesis and structure of copper(Ⅱ) complex [Cu(C5H5N)2(H2O)(C6H5COO)2]. Chinese J. Struct. Chem., 2001, 20(1):4-7.
[14]Aranda P, Kun R, MartínLuengo M. A, et al. Titaniasepiolite nanocomposites prepared by a surfactant templating colloidal route. Chem. Mater., 2008, 20(1):84-91.
[15]尹荔松, 沈 辉, 张进修. 纳米TiO2粉晶的光学特性研究.电子学报, 2002, 30(6):808-810.
[16]周时凤, 洪樟连, 赵芙蓉, 等(ZHOU Shi-Feng, et al). 一种可见光响应纳米TiO2粉体的光响应特性表征. 无机材料学报(Journal of Inorganic Materials), 2006, 21(4):783-788.
[17]丁开宁. 金属修饰TiO2(110)表面的电子结构和表面态的理论研究. 福州:福州大学博士论文, 2005.
[18]Bao L L, Mahurin S M, Dai S. Controlled layerbylayer formation of ultrathin TiO2 on silver island films via a surface Sol-Gel method for surfaceenhanced raman scattering measurement. Anal. Chem., 2004, 76(15):4531-4536.