The invention discloses a low-temperature two-
step method for preparing a composite
anatase type
titanium dioxide visible light catalyst, and belongs to the visible light catalyst. The preparation method comprises the following steps of: 1, adding
titanium-containing precursor into
alcohol, uniformly mixing and then adding a
dopant, fully stirring, then adding an inhibitor and de-ionized water respectively, and performing water bath heating to prepare
colloid containing
titanium and
doping element; and 2, cooling the prepared
colloid to
room temperature, transferring into a high-pressure-resistant container, adding a
thermal decomposition type compound into the
colloid, then quickly sealing the container, heating to perform reaction, preserving heat, obtaining precipitate after the reaction is finished, filtering the precipitate and washing with the de-ionized water and then
drying to prepare the composite
anatase type
titanium dioxide visible light catalyst. The method has the advantages that: 1, the catalyst is prepared under the condition of 80-100 DEG C, and the
energy consumption is favorably reduced during preparation; and 2, subsequent high-
temperature treatment is not required in the method, the defect of
high probability of losing the
doping element through the high-
temperature treatment is avoided, and the photo-catalytic performance is favorably improved.