电解液性质对TiO_2纳米管阵列形貌及生长机理的影响

Influences of Electrolyte Characteristic on Morphology and Growth Mechanics of TiO_2 Nanotube Arrays

采用电化学阳极氧化法在纯钛片表面制备出了结构整齐有序的TiO2纳米管阵列,主要研究了电解液的性质、浓度以及氧化时间对TiO2纳米管阵列形貌的影响,并对不同电解液中TiO2纳米管阵列的形成机理进行了初步探讨.结果表明:在不同浓度的HF酸电解液中均可制备出规则、均匀的TiO2纳米管阵列,管径均匀,表面平整,但是纳米管的长度均较短,约为300～350nm.在高浓度HF电解液中,同时获得了规则的纳米管阵列和纳米棒阵列.在0.5wt%NaF和1mol/LNa2SO4中性电解液中也可以制备出表面光洁、排列整齐有序的TiO2纳米管阵列,纳米管长度明显长于HF酸电解液中获得的纳米管阵列,达到了700nm,但是阵列的表面平整度较差.在乙二醇+0.6wt%NH4F+2vol%H2O有机电解液体系中可以制得超长的TiO2纳米管阵列,管径在150nm左右,管长可达6μm.

The highly ordered TiO2 nanotube arrays were fabricated by anodic oxidation of titanium foil.The influences of electrolyte characteristic and concentration as well as anodization time on the morphology of TiO2 nanotube arrays were studied,and the growth mechanics were analyzed.Results show that regular ordered TiO2 nanotube arrays can be prepared in hydrofluoric acidic solution,the pipe diameters are uniform and the surfaces are smooth,but the lengthes are limlited in the range from 300nm to 350nm.TiO2 nanotube arrays and nanorod arrays can be obtained in high concentrate hydrofluoric acidic solution.TiO2 nanotube arrays with high slenderness ratios and rough surfaces are prepared in sodium fluoride and sodium sulfate electrolyte with lengths of 700nm which are longer than those prepared in hydrofluoric acidic electrolyte.TiO2 nanotube arrays with pipe diameters of about 150nm can also be prepared in glycol,ammonium fluoride and water ethyleneglycol electrolyte,the lengths of which can reach up to 6μm.