【作者】 张其君；

【导师】 王成伟；

【作者基本信息】 西北师范大学 ， 凝聚态物理， 2011， 硕士

【摘要】 二氧化钛具有独特的湿敏、气敏、紫外光吸收、光电转化及光催化性能,在传感器、介电材料、自清洁材料、有机-无机太阳能电池、光催化降解污染物等领域有着广阔的应用前景。TiO₂纳米管因其特殊的结构而表现出更加优异的性能。若将TiO₂纳米管（或多孔）膜高质量地转移至透明导电基底FTO上,制备出多孔TiO₂/FTO纳米薄膜,则其可直接作为光电极,以便在光电转换等领域得到更好的应用。本论文以“TiO₂/FTO纳米管有序阵列光电极的制备、CdS修饰及其光学特性的研究”为题,主要述及以下几方面的研究工作:1.以金属钛片为基底（0.2 mm）,采用连续三步阳极氧化法,在含有NH4F的乙二醇溶液内,成功制备出大面积（18 mm×11 mm）自持多孔TiO₂纳米管阵列膜（管长≤1.5μm）。通过进一步研究发现,该自持薄膜不仅具有较高的晶化程度、较高的透射率（400²500 nm）,而且不同的阳极电压对薄膜的透射强度及光学能隙（Eg）都有明显的调制作用。2.利用实验室配制的TiO₂溶胶,成功将自持TiO₂纳米管阵列膜转移粘结至FTO导电玻璃上,经退火处理后形成TiO₂/FTO纳米管阵列膜光电极。3.采用序贯化学浴沉积方法,对TiO₂/FTO纳米管阵列膜光电极做CdS纳米颗粒修饰。实验发现,经CdS纳米颗粒修饰的TiO₂/FTO光电极,其帯隙宽度由原来的3.22 eV减小至2.43 eV,光吸收带边也由原来的380 nm红移至554 nm。研究表明,这种转移粘结法制备的TiO₂/FTO半透明光电极经CdS纳米颗粒修饰后,具有很宽的光谱响应特性,这是光电转换应用研究所期待的。这项研究对基于TiO₂纳米管阵列的光催化及光伏太阳电池的应用研究将是非常有益的。更多还原

【Abstract】 TiO₂ nanomaterials have been widely studied due to their unique electrical and electrochemical properties which are suitable for sensing, catalysis and solar cells. In recent years, TiO₂ nanotubes with high surface-to-volume ratios have received considerable attention because of their potential applications of highly efficient photocatalysis and photovoltaic cells. If the TiO₂ nanotube membranes could be transferd onto the FTO substrates, the transparent and conductive TiO₂/FTO photoelectrode would have a better application in the photoelectric conversion filed. This dissertation titled“Highly ordered TiO₂/FTO nanotube array photoelectrode:fabrication, modification of CdS and its optical properties”mainly describes the following work and results:1. The large-scale （18 mm×11 mm）, highly-ordered, vertically-oriented free-standing TiO₂ nanotube membranes were fabricated by three-step anodization Ti foils（0.2 mm） in ethylene glycol containing 0.25 wt.% NH4F. It is found that the optical energy gap （Eg） of TiO₂ nanotube membranes could not only have high transmissivity （400²500 nm）, but also be effectively modulated by different anodic voltage. Obviously, this work would be beneficial to apply in organic-inorganic photovoltaic devices.2. Then the as-prepared free-standing membranes were transferred to FTO-coated glass substrates with TiO₂ sol, and the semitransparent TiO₂/FTO photoelectrode was obtained after annealing treatment.3. The TiO₂/FTO photoelectrode was modified with CdS by the sequential-chemical bath deposition （S-CBD） method in order to extend the optical absorption range of bare TiO₂/FTO. The measurement results show that the band-gaps decrease from 3.22 eV for bare TiO₂/FTO to 2.43 eV for CdS-modified TiO₂/FTO. Meanwhile, the optical absorption band-edges of CdS-modified TiO₂/FTO have efficiently shifted from 380 nm to 554 nm, which could lead to an extended optical absorption range from the ultraviolet to the visible.更多还原