电化学方法制备掺杂二氧化钛纳米管阵列

Preparation of Doped Titania Nanotube Arrays by an Electrochemical Method

通过阳极氧化制备二氧化钛纳米管阵列。然后用制成的纳米管阵列作阴极、Pt作阳极,分别以Zr(NO3)4、NH4Cl及Zr(NO3)4和NH4Cl的混合溶液为电解液,制备锆掺杂、氮掺杂及锆、氮共掺杂二氧化钛纳米管阵列。通过FESEM、UV-vis漫反射、XRD、XPS等手段对纳米管阵列进行表征。结果表明,制成的纳米管阵列管径约70nm,管长约400nm。共掺杂后的吸收带边有了明显的红移。在锆掺杂纳米管中锆含量是0.51%,氮掺杂纳米管中氮含量为1.92%,共掺杂中锆、氮含量分别是0.77%和1.29%(均为原子分数)。N1s峰在单独掺氮纳米管中是一个峰,而在混合掺杂中是双峰,说明氮在单独掺杂和混合掺杂中的存在状态并不一致。通过降解罗丹明B水溶液对其光催化性能进行检测。结果显示,锆掺杂可以增强TiO2纳米管阵列在紫外光下的催化活性,氮掺杂提高了TiO2纳米管阵列在可见区的光催化活性,锆、氮共掺杂产生了协同作用,使TiO2纳米管阵列的催化活性在紫外和可见区都得到了明显的提高。

TiO2 nanotube arrays were prepared by anodic oxidation, and then an electrochemical process was conducted using the as-prepared TiO2 nanotube arrays as cathode and Pt as anode; the electrolyte was Zr（NO3）4, NH4Cl and mixture of Zr（NO3）4 and NH4Cl, respectively. Zr-doped, N-doped and Zr, N-codoped titania nanotube arrays were prepared. The nanotube arrays were characterized by FESEM, UV-vis DRS, XRD and XPS. FESEM show that the nanotube arrays are about 70 nm in diameter and 400 nm in length. UV-vis DRS reveal that the absorption band of co-doped nanotube arrays moves towards long wavelength. XPS indicate that the concentrations of Zr in Zr/TiO2, N in N/TiO2 and Zr, N in Zr, N/TiO2 nanotube arrays are 0.51%, 1.92%, 0.77% and 1.29%, respectively （atom fraction）. N1s exhibits a single peak in N/TiO2 and double peaks in Zr, N/TiO2 nanotube arrays, which indicates that N forms are different in N/TiO2 and Zr, N/TiO2 nanotube arrays. The photocatalytic activities were tested by degradation of Rhodamine B aqueous solution. The results show that Zr-doping improves TiO2 photocatalytic activity in UV region, N-doping improves TiO2 photocatalytic activity in visible light region, and Zr, N-codoping evokes synergetic reaction and enhances TiO2 photocatalytic activity greatly both in UV and Vis regions.