Research On Fabrication Of Self-Supported Three-Dimensional Micro-Nanostructure TiO₂ Based On Femtosecond Laser Structuring

Titanium dioxide?TiO₂?is widely used in photocatalytic,dye-sensitized solar cells,biomedical and other fields for its advantages of non-toxic,high photoelectric conversionefficiencyandgoodstability.Inthispaper,self-supported micro-nanostructure TiO₂ was fabricated on titanium substrate by the combination of femtosecond laser structuring with chemical treatment.The primary microstructure was prepared by femtosecond laser structuring,then two different chemical treatments?NaOH hydrothermal method and H₂O₂ oxidation?were conducted to form nanostructure on the surface of primary microstructure.For its superior specific surface area and light utilization efficiency,the photocatalytic performance of multiple micro-nanostructure TiO₂ obtained in our study is improved and exhibit different wetting trend.Femtosecond laser combined with NaOH hydrothermal treatment can be used to prepare three-dimensional micro-nanostructured TiO₂ composed of nanowires and nanosheets on the pre-microstructure surface.The degradation efficiency of methyl orange increased by about 40%than that of flat surface nanostructure under the same conditions.The Ti surface with micro-nanostructure TiO₂ treated by this method exhibits super-hydrophilic properties and can maintain for 10 days after exposure to the surrounding environment,and with contact angle less than 20?even after 50 days.Micro-structure TiO₂ composed of nanoporous was prepared on the surface of microstructure after femtosecond laser structuring by thecombination of H₂O₂oxidation.A degradation efficiency of methyl orange increased by about 80%than that of flat surface nanostructure is received here.The super-hydrophilic titanium surface by this method is easily transferred to the hydrophobic state,it becomes a superhydrophobic state after exposure to air for 10 days?contact angle more than150°?.