中文摘要：

首先以沉积一沉淀法制备AgBr／TiO2复合催化剂，然后采用离子交换法制备出新型的异质结型AgI／AgBr／TiO2光催化剂．利用XRD和UV-Vis对AgI／AgBr／TiO2光催化剂进行了表征．以甲基橙为染料模型，在可见光条件下（500W、λ〉420rim）研究了AgI的含量对AgI／AgBr／TiO2催化活性的影响．结果表明，AgI拓展了催化剂的吸收光谱范围；AgI生成量为AgBr的5％时，AgI／AgBr／TiO2的催化活性最高．AgI／AgBr异质结的形成有利于光生电子和空穴的分离，提高AgI／AgBr／TiO2的催化活性．

英文摘要：

A novel AgI/AgBr/TiO2 photocatalyst was synthesized by ion exchange of AgBr/ TiO2 substrate prepared via deposition-precipitation method. AgI/AgBr/TiO2 was characterized by XRD and UV-Vis. The photocatalytic activity of AgI/AgBr/TiO2 was measured with methyl orange （MO） as dye model under the visible light condition （500 W,λ〉 420 nm）. The results showed that AgI broadened the light absorption range of AgBr/TiO2 catalyst in visible light area and raised the photocatalytic activity of AgBr/TiO2. The maximum of photocatalytic activity of AgI/AgBr/TiO2 could be obtained when the AgI formation was 5 % of AgBr. AgI/AgBr heterojunction was beneficial to separate the photogenerated elections and holes and then raised the photocatalytic activity of AgI/AgBr/TiO2.