Ag改性TiO2纳米管阵列的光电化学性能研究

摘要

Ag modified TiO2 nanotube arrays was prepared by anodic oxidation and photodeposition methods. The crystal type and morphology of the samples were analyzed by X-ray diffraction and SEM techniques. And the photoelectrochemical proper-ties were investigated using I-E, photopotential, photocurrent response, and Mott-Schottky through electrochemical worksta-tion with three-electrode system. The results show that the inside diameter of TiO2 nanotube arrays is approximately 60 nm with wall thickness of 30 nm, and the diameter of Ag nanoparticle is about 15~20 nm. The influence of photodeposition time on the Ag size is little, which only increases the deposition amount of Ag. Ag modification can effectively promote the separa-tion of electrons and holes, through which the efficiency of light utilization is improved. The Ag-TiO2 nanotube arrays present excellent photoelectrochemical properties under the xenon lamp illumination, in which the photocurrent, carrier density, pho-toconversion efficiency can reach 0. 28 mA/cm2, 2. 21×1022 cm-3, and 4. 10%, respectively.%采用阳极氧化法及光沉积法制备Ag改性TiO2纳米管阵列,采用XRD、SEM分析样品的晶型和形貌特征,并利用电化学工作站三电极体系通过I-E、光生电位、光电流响应及莫特肖特基曲线考察样品的光电化学性能。结果表明：TiO2纳米管阵列的内径约为60 nm,管壁厚度约为30 nm,Ag颗粒粒径为15~20 nm；光沉积时间对Ag颗粒尺寸几乎没有影响,仅增加了Ag粒子的沉积量；Ag的改性能够有效地促进电子和空穴的分离,提高了对太阳光的利用率,在氙灯照射下,Ag-TiO2纳米管阵列具有良好的光电化学性能,光电流达到0．28 mA/cm2,载流子密度ND 为2．21×1022 cm-3,光转化率可达到4．10%。