The invention provides a self-cleaning super-hydrophilic thin film and a preparation method thereof. The preparation method comprises the steps of using
tetra-n-butyl
titanate as a precursor of TiO2, using
anhydrous ethyl
alcohol as
solvent, adding glacial
acetic acid, and magnetically agitating at
room temperature to obtain solution A; synchronously, taking
distilled water and
anhydrous ethyl
alcohol, adding
doping salts, and magnetically agitating the mixture to obtain solution B; slowly adding the solution B to the solution A, adding
hydrochloric acid to adjust pH value to 3-5, agitating to obtain TiO2
sol, and preparing a rare-earth-doped nanometer-sized TiO2 thin film by using a film drawing
machine; immersing a substrate into the
sol, drawing and plating a film after
glass sheet and liquid surface are stable;
drying after plating a layer of film and cooling at
room temperature; repeating the steps to prepare the
rare earth-doped nanometer-sized TiO2 thin film with different
layers; thermally treating the base plated with the TiO2 thin film, and directly using the film-plated base. The thin film of the invention overcomes the weak points that nanometer-sized
powder easily aggregates and is not easily recovered, the obtained
crystal form is table, and the thin film has excellent self-cleaning and hydrophilic capacities.