TECHNOLOGY FOCUS - INORGANIC CHEMISTRY - Preparation: The preparation method of the photoelectric conversion film comprises: (a) preparation for colloid solution of titania nanometer slice: mixing and grinding cesium carbonate (Cs2CO3) and titanium dioxide (TiO2) according to mol ratio of 1:5.1-1:5.5, calcining mixture in muffle for 30-60 minutes at 800-900 degrees C, grinding and calcining for 20-24 hours at 800-900 degrees C, cooling and grinding again for 20-24 hours at 800-900 degrees C to obtain the laminated cesium titanate (CTO) having formula given in the specification; mixing and stirring CTO and 1.0-1.5 mol/L HCL for 3-4 days according to liquid-solid ratio of 50-200 ml/g, and replacing 1.0-1.5 mol/L HCL every 24 hours, washing the product by de-ionized water to be neutral in order to obtain proton-type titanate (HTO) having formula given int the specification, stirring HTO and solution of tetra-n-butyl ammonium hydroxide (TBAOH) with concentration of 0.0017-0.5 mol/L for 7-10 days at room temperature in order to obtain ivory suspension according to liquid-solid ratio of 250-300 ml/g, using a 10000~12000 rotations/minute high-speed centrifugation for 1-2 times and 15-30 minutes in order to obtain colloid solution of titania nanometer slice; obtaining the de-ionized water of secondary distillation through secondary distillation; (b) preparation for colloid solution of manganese dioxide nanometer slice: adding mixed solution containing 0.6-0.8 mol/L sodium hydroxide (NaOH) and 1.0-1.5 mol/L hydrogen peroxide (H2O2) in 0.3-0.4 mol/L manganese nitrate (Mn(NO3)2) according to 6:1-8:1 mol ratio of H2O2 and manganese ion (Mn2+) and 3:1-4:1 mol ratio of hydroxide ion (OH-) and Mn2+, stirring for 20-30 minutes, filtering and moving to polyfluortetraethylene container; adding 2.0-3.0 mol/L NaOH solution according to 2:1-4:1 mol ratio of OH- and Mn2+ and in 50-80% filled degree, stirring the mixture to be a paste, sealing the polyfluortetraethylene container in water-heated retort, and heating for 15-20 hours at 150-160 degrees C; naturally cooling the water-heated retort to be at room temperature and opened for pumped filtering, using de-ionized water of secondary distillation for washing the mixture to be neutral, drying the filter cake for 6-9 hours at air atmosphere of 70-80 degrees C to obtain the laminated manganese dioxide; adding solid powder of laminated manganese dioxide in 1.0-1.5 mol/L HCL solution to be stirred at room temperature and for 3-5 days according to 10:1-15:1 mol ratio of hydrogen ion (H+) and laminated manganese dioxide, replacing 1.0-1.5 mol/L HCL solution for one time every 24 hours, pumped filtering the mixed solution, using the de-ionized water of secondary distillation for washing the mixture to be neutral, drying the filter cake for 6-9 hours at air atmosphere of 70-80 degrees C to obtain hydrogen-substituted manganese dioxide; hydrogen-substituted manganese dioxide is added in tetra-n-methyl ammonium hydroxide (TMAOH) solution with mass fraction of 1.5-2.0% to be stirred for 7-10 days at room temperature according to 2:1-4:1 mol ratio of TMAOH and hydrogen-substituted manganese dioxide, using the 10000-12000 rotations/minute high-speed centrifuge to mix solution for 5-15 minutes to obtain colloid solution of manganese dioxide nanometer slice; (c) surface treatment of film substrate, where the film substrate is a kind of quartz or Indium-Tin Oxide (ITO): for quartz substrate, ultrasonic washing the quartz for 20-30 minutes respectively by acetone, absolute ethyl alcohol, de-ionized water of secondary distillation in turn to remove surface crud, dipping quartz in washing liquid that is prepared according to 3:7-4:6 volume ratio of H2O2 with 30~33% mass fraction and concentrated sulfuric acid with 95-98% mass fraction, ultrasonic washing for 30-60 minutes, using de-ionized water of secondary distillation for washing and using nitrogen gas (N2) blow-drying; (d) for ITO substrate, ultrasonic washing of quartz for 20-30 minutes respectively by acetone, absolute ethyl alcohol, de-ionized water of secondary distillation in turn, and dipping the substrate is dipped in mixed solution that is prepared according to 1:1:5-2:2:5 volume ratio of H2O2 with 30-33% mass fraction, concentrated ammonia with 25-28% mass fraction and de-ionized water of secondary distillation, and boiling at 70-80 degrees C for 30-60 minutes, and washing with de-ionized water of secondary distillation and N2 blowing; and (e) preparation for photoelectric conversion film containing titania and manganese dioxide nanometer slices: vertically dipping the washed film substrate in 2.0-2.5 g/L aqueous solution of polyethylenimine, and removing after 20-30 minutes, washing with de-ionized water of secondary distillation and N2 blowing, mounting a layer of positive charge on substrate; dipping substrate with positive charge in 0.08-0.5 g/L mixed colloid solution of titania nanometer slice and manganese dioxide nanometer slice having concentration ratio of titania nanometer slice and manganese dioxide nanometer slice equal to 1:1-2:1, removing the substrate after 20-30 minutes, washing with de-ionized water of secondary distillation, and N2 blowing, coating the substrate with a layer of negative charge; dipping substrate in 15-20 g/L aqueous solution of polydiene propyl dimethyloxide ammonium, removing after 20-30 minutes, washing with de-ionized water of secondary distillation, and N2 blowing, and coating with positive charge; repeating the assembly process of mixed colloid solution and aqueous solution of polydiene propyl dimethyloxide ammonium, and obtaining the multi-layer assembled photoelectric conversion film containing titania nanometer slice and manganese dioxide nanometer slice. Preferred Components: The titania nanometer slice is inorganic semiconductor material having a formula given in the specification, where titanium blank is included when titanium element is lost, the delta represents mol fraction of titanium blank, where it is greater than or equal to 0.07 and less than or equal to 0.11, and the 4 delta represents the negative charge of titania nanometer slice. The titanium-oxygen octahedron is formed to be corrugated slice structure through common side and point. The manganese dioxide nanometer slice is inorganic semiconductor material having a formula of (Mn sigma 3+Mn1- sigma 4+)O2 sigma -, where Mn3+ and Mn4+ respectively represent manganese ion of valences positive 3 and negative 4; and the sigma represents mol fraction of Mn3+ and Mn4+. The manganese-oxygen octahedron is formed to be slice structure through common side.sigma = greater than or equal to 0.2 and less than or equal to 0.4.Preferred Composition: The corresponding thickness of the titania nanometer slice is 0.7-1.2 nm, and the side size is 50-900 nm. The corresponding thickness of the manganese dioxide nanometer slice is 0.6-1.1 nm, and the side size is 50-300 nm.