The invention provides a preparation method of an iron lattice doped aluminum
oxide membrane, and belongs to the technical field of preparation of inorganic
ceramic membrane materials. According to the method, a
sol-gel process is adopted, Fe < 3 + > is doped and introduced into an aluminum
oxide precursor
system, the doped Fe < 3 + > promotes gamma-to-alpha phase transformation temperature to be reduced on one hand, and on the other hand,
grain growth and pore merging are effectively inhibited, so that the membrane pore size is remarkably reduced, and the pore size distribution range is narrowed. Fe < 3 + > and an aluminum source are subjected to co-
hydrolysis and co-polycondensation in the
sol stage, and a uniform iron-aluminum composite precursor
system is formed; after subsequent heat treatment, Fe enters alpha-Al2O3
crystal lattices in a
crystal lattice
doping mode and forms a stable Fe-O-Al bonding structure, surface hydroxyl introduced by
crystal lattice
doping enhances the surface hydrophilicity of the membrane and weakens
irreversible adsorption of
protein, and thus more stable flux and better anti-
pollution performance are achieved while the
high protein rejection rate is guaranteed.