Method for preparing rice hull active carbon/silicon dioxide/titanium dioxide composite material

The invention discloses a method for preparing a rice hull active carbon/silicon dioxide/titanium dioxide composite material in the technical field of preparation of nano titanium dioxide photocatalysts. The method comprises the following steps of: carrying out acid cleaning on rice hull powder; adding an NaOH solution into the rice hull powder which is subjected to acid cleaning and carrying outalkali cooking to obtain mixed size consisting of rice hulls and sodium silicate; preparing a rice hull/silicon dioxide/titanium dioxide precursor; and finally carrying out carbonization and activating treatment to prepare the rice hull active carbon/silicon dioxide/titanium dioxide composite material. The rice hulls and nano titanium dioxide are combined in a chemical bond mode by silicon dioxide. The rice hull active carbon/silicon dioxide/titanium dioxide composite material not only has excellent adsorption performance of rice hull active carbon, but also has excellent photocatalysis performance of the nano titaniu