二氧化鈦因其化學性質、機械性質及光學特性的優越性，成為一個具潛力的光觸媒。二氧化鈦具有較大能隙(3.2 eV)，為紫外光波段，故其使用受到了限制。若二氧化鈦能隙能縮減至可見光範圍可以大幅增加其應用性。此外，其表面積也對光觸媒效率有很大的影響，奈米柱的光觸媒是一個可以發展的策略。
在本實驗中，利用反應性濺鍍法直接沉積二氧化鈦奈米柱於基板上。沉積時的工作距離、濺鍍壓力及基板的形貌為主要影響二氧化鈦奈米柱的關鍵。此外，利用氮離子及鉻離子的摻雜來調控二氧化鈦之能隙並以薄膜繞射儀、二次電子顯微鏡、穿透式電子顯微鏡及紫外光-可見光光譜儀來分析其特性。討論奈米結構、氮與鉻離子的摻雜及降解時之環境(pH) 對光降解甲基藍的影響。最後發現摻雜11%氮離子及20%鉻離子在pH=7的環境中其光降解的效率最高。本實驗證明可藉由摻雜它種離子以提升二氧化鈦奈米柱光觸媒的效率。

TiO2 is a promising photocatalyst due to its superior chemical, mechanical, and optical properties. However, the wide band gap ( 3.2 eV) of TiO2 has limited its application in the UV range. Band gap tuning is extremely critical to extend its applications under visible light,. In addition, high aspect ratio morphology tuning, ex. nanorods structure, is another strategy to enhance its photocatalysis.
We have tried to grow TiO2 nanorods directly on a substrate by reactive sputtering. We have discussed the key factors to grow the TiO2 nanorod structure by sputtering, including the working distance, working pressure and substrate morphology. Nitrogen and chromium were incorporated into TiO2 nanorods to tune their band gaps. Various characterization tools such as GIXRD, SEM, TEM, and UV-vis were used to study the properties of TiO2 nanorods. Methylene blue (MB), which can be photodegraded, heavily depending on the morphology of TiO2, the amounts of Cr and N dopants, and the chemical environment (pH), was used as the target pollutant for a photodegradation test. We found N doped TiO2 nanorods made by the approach (b) and Cr-gradient doped TiO2 nanorods showed the best photodegraded efficiency at pH = 7. Modification of pristine TiO2 nanorods has been demonstrated an effective approach to enhance their photodegration ability.

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