Semiconductor photocatalysis

as a new technology using light energy

is an important research field of pollutant control. Novel Bi

5

O

7

I photocatalysts have attracted much attention in recent years. The structure

preparation methods

modification methods and photocatalytic oxidation mechanism of Bi

5

O

7

I photocatalysts are reviewed in detail. The crystal structure of Bi

5

O

7

I is similar to that of bismuth oxyhalide. Its unique internal electrostatic field can promote the separation of photogenerated electrons and holes in th

e process of photocatalytic reaction. Although Bi

5

O

7

I has an appropriate band gap

it also has the disadvantage of high recombination efficiency of photogenerated electrons and holes. The separation of photogenerated electrons and holes can be enhanced by constructing p-n type heterojunction

Z-scheme heterojunction and metal ion deposition

thereby improving the photocatalytic oxidation performance of Bi

5

O

7

I based photocatalyst.