掺杂La^(3+)对纳米TiO_2薄膜电极光电催化氧化甲醇的影响

Influence of La^(3+) Doped TiO_2 on Photocatalyticoxidating Methanol

采用改进的溶胶凝胶法制备了一系列La3+掺杂的纳米TiO2薄膜电极.由SEM图可以看出,镧的掺杂使电极表面粒径变小;通过光电化学方法研究发现,当掺杂La3+的摩尔分数为0.50%时光电流最大,是纯TiO2电极的2.25倍.用瞬态光电流谱研究了电极在甲醇溶液中的光电转换过程,结果说明TiO2薄膜为N型半导体,镧离子的掺杂改变了电极的表面形貌.

The La^3＋ doped TiO2 films with variant doping contents were prepared by sol-gel method. The SEM result shows that, after doping, the sizes of particles become small, the surface profile is changed. Photoelectrochemical measurements show that the photocurrent is maximum at 0.50% of La^3＋ content, which is 2.25 times higher than that of pure TiO2 nanoporus film electrode. The photoinduced electron transfer process indicates that the TiO2 porus film shows characteristics of semiconductor of N-type. The mechanism of electro-photo catalisticprocess has been discussed.