Preparation method of metal ion doped TiO2 photo-anode

The invention discloses a preparation method of a metal ion doped TiO2 photo-anode. The preparation method comprises the following steps: S1, firstly carrying out cleaning and primary treatment on an FTO conducting glass substrate; S2, carrying out scrapping coating operation on the conducting surface of the FTO conducting glass substrate, so that TiO2 sizing agent of a compact layer is scrapped and coated on the conducting surface of the FTO conducting glass substrate to form the compact layer, and TiO2 particles in the compact layer are doped with Nb element; S3, drying the compact layer, then carrying out scrapping coating operation on TiO2 sizing agent of a scattering layer on the surface of the compact layer to form the scattering layer and drying the scattering layer, and then calcining a sample, wherein TiO2 particles in the scattering layer are doped with Nb element; and S4, carrying out sensitized treatment on the sample scrapped and coated with the compact layer and the scattering layer. According t