Ni-TiO_2介孔材料的低热固相合成及其光降解甲基橙的动力学

Synthesis of Ni-doped TiO_2 Mesoporous Material via Solid-state Reaction at Low Temperature and its Kinetics of Methyl Orange Photodegradation

以十六烷基三甲基溴化铵为模板,通过钛酸丁酯与六水氯化镍的固相反应直接合成了镍掺杂的二氧化钛(Ni-TiO2)介孔材料.用X射线衍射、高分辨透射电镜、N2脱附-吸附、红外、紫外以及拉曼光谱仪等分析技术对材料进行了物相与表面织构表征;通过电感耦合等离子发射光谱仪对材料的元素组成进行分析;同时研究了材料对甲基橙的光降解性能.结果表明,所得的介孔材料是锐钛矿型,金属镍已进入了二氧化钛骨架,镍的含量为3.62wt%;孔壁是由无定形的晶界与微晶组成,并伴有结构缺陷和痕量的金属镍氧化物;其BET比表面积为102.4m2/g,孔半径分布中心为2.4nm.在298K下,Ni-TiO2介孔材料对甲基橙溶液的紫外光降解行为遵循准一级动力学反应规律,其反应速率常数比纯TiO粉体大二倍,且存在明显的浓度效应.

With tetrabutyl orthotitanate and nickel（Ⅱ） chloride hexahydrate as original materials and cetyltrimethylammonium bromide as a template agent, Ni-doped TiO2 mesoporous material was successfully prepared by solid-state reaction. The textural properties of the materials were characterized by the X-ray diffraction, high resolution transmission electron microscope （HRTEM）, N2-physisorption at 77K, fourier transform infrared spectroscope （FTIR）, Raman spectroscope and ultraviolet visible light spectroscope. The components of Ni-TiO2 were determined by inductively couple plasma atomic emission spectrometry. The photodegradation properties of this material for methyl orange were detailedly investigated. The results show that nickel is incorporated into the framework of TiO2 with content of 3.62wt%. Furthermore, Ni-doped TiO2 with anatase phase is laced the wall with the amorphous grain boundary and crystallite with some defect structures and nickel oxides. For Ni-doped TiO2 mesoporous material, the specific surface area of 102.4m2/g and the pore radii distribution centre of 2.4nm are obtained. At 298K, the rule of pseudo-first-order reaction and the concentration effect are found in the photodegradation process of methyl orange on the Ni-doped TiO2 mesoporous material surface, where the reaction rate constant is two times higher than that on pure TiO2.