单斜与锐钛矿双晶相TiO_2/MWNTs复合材料的制备及其可见光光催化活性

Preparation of Bi-crystalline(Monocline and Anatase) TiO_2/MWNTs Composite and Its Photocatalytic Activity under Visible Light Irradiation

以超强耐酸碱的表面活性剂-丁基封端脂肪醇聚氧乙烯醚作为晶型调节剂,利用钛酸丁酯和氢氧化钠的水热反应制备了单斜相与锐钛矿相双晶相TiO2/多壁碳纳米管(简称MWNTs)复合材料,并考察了复合材料的可见光光催化活性。结果显示:MWNTs的加入可调控TiO2的晶相组成,增强TiO2的光催化活性,其中含5%MWNTs的样品具有较高的催化降解效率;随煅烧温度的升高,样品的光催化活性大幅提升。其机理归因于(1)促进单斜相和锐钛矿相双晶相结构的形成;(2)碳纳米管优良的导电作用及碳纳米管/TiO2间的异质结效应;(3)高温下碳纳米管分解产生的碳元素掺杂作用。

A bi-crystalline （monocline and anatase） titanium dioxide/multi-walled carbon nanotubes （TiO2/ MWNTs） composite was prepared through the hydrothermal reaction of tetrabutyl titanate and sodium hydroxide with butyl end-capped fatty alcohol ethoxylates as phase regulator, and its photocatalytic property under visible light irradiation was investigated. The results show： the adding of MWNTs can affect crystalline phase and improve the photocatalytic activity of TiO2, the product with 5% MWNTs exhibits the greatest photocatalytic degradation rate; the photocatalytic activity of the products greatly increases with the increase of calcination temperature. The effect of doping MWNTs originates from （1） facilitating the formation of bi-crystalline phase with monocline and anatase, and （2） excellent conductivity of MWNTs, or （3） the carbon doping effect rooting in the breaking down of MWNTs under higher temperature.