铝合金表面制备二氧化钛薄膜及其光催化活性研究

Preparation and Photocatalytic Activity of TiO_2 Thin Films on Al Alloys

分别以阳极氧化处理的6061铝合金和纯铝为载体,用液相沉积的方法在载体上制备了二氧化钛薄膜.结果表明,在6061铝合金上的TiO2纳米薄膜呈现带有孔洞的竹节状结构,而纯铝基片上的TiO2纳米薄膜具有良好的一维贯通结构.这主要是在AAO模板制备过程中,由于铝合金中的合金元素Mg被氧化,其产生的氧化物体积比Al2O3的体积小所致.在铝合金表面的TiO2薄膜光催化性能优于纯铝表面的TiO2薄膜.铝合金表面制备的TiO2薄膜因其特殊的带孔洞的竹节状结构,使其比表面积比纯铝上的TiO2薄膜大,因此其光降解甲基蓝效果更好.TiO2对甲基蓝的光催化降解符合一级反应动力学公式,在0.1 mol/L的氟钛酸铵溶液中沉积得到的TiO2薄膜光催化性能最好,表观反应速率为k=0.00444/min.

Using anodized 6061 aluminum alloy and pure aluminum as the templates,TiO2 thin films were prepared through a liquid deposition method.The TiO2 thin film fabricated on the 6061 aluminum alloy substrates appears as bamboo-like structures with holes,whereas that prepared on anodized pure aluminum substrate has one-dimensional tubular structures.The main reason is that magnesium in aluminum alloy is oxidized to form magnesium oxide which has a lower volume than that of Al2O3.The photocatalytic ability of the TiO2 films prepared on the aluminum alloy is superior to that of the films fabricated on the pure aluminum.TiO2 prepared on aluminum alloy has higher specific surface area due to its bamboo-like structures with holes,leading to better performance in the degradation of methylene blue.The photocatalytic performance of the TiO2by the degradation of aqueous methylene blue is in accordance with the first kinetic equation.TiO2films deposited in 0.1 mol/L（NH4） TiF6 solution obtain the best photocatalytic performance at apparent reaction rate of 0.00444/min.