Study On Structure Design And Performance Of High-efficiency Titanium Oxide-based Photocatalysts

As a novel type of pollutant,antibiotics have posed a non-negligible hazard to the environment and health.The photocatalytic technology can effectively solve the problem of antibiotic pollution due to its high degradation efficiency,no secondary pollution,low energy consumption and simple operation.Ti O₂ nanomaterials are cheap,stable and efficient photocatalysts for the photocatalytic degradation of antibiotic contamination.However,the activity is still limited by insufficient photon absorption and charge extraction.Therefore,the photocatalytic ability of Ru-doped mesoporous Ti O₂ crystals and double perovskite Cs₂AgBiBr₆ composite mesoporous Ti O₂ crystals were studied in this paper.The main research contents and conclusions of this paper are summarized as follows:（1）Ruthenium-doped mesoporous Ti O₂ crystals with oxygen vacancy-rich(Ti_1-xRu_xO_2-y)were prepared by two-step corroding method using step-like layered K₂Ti_8-xRu_xO₁₇ as a precursor.The removal of potassium ions and reconfiguration of[Ti O₆]octahedra in K₂Ti_8-xRu_xO₁₇ lead to the formation of mesoporous crystals.Meanwhile,the addition of Ru³⁺can create the Ti³⁺species and oxygen vacancies in situ inside the crystals,and extend the light absorption range from ultraviolet absorption to the entire visible region.For Ti_1-xRu_xO_2-y with different Ru-doped concentrations,mesoporous Ti_0.95Ru_0.05O_2-y crystal has the best photocatalytic activity.Meanwhile,the mesoporous Ti_0.95Ru_0.05O_2-y crystals show a 98.74%degradation efficiency of tetracycline hydrochloride in 80 minutes under simulated sunlight(AM1.5 G 100 m W cm^-2)illumination.（2）The cubic Cs₂AgBiBr₆ with uniform size was prepared by hot-injection method,and the Cs₂AgBiBr₆/Ti O₂ composite was prepared by electrostatic adsorption and hot evaporation solvent,which effectively improved the problems of low photon absorption rate and fast carrier recombination of Ti O₂.Due to the difference in work function between Cs₂AgBiBr₆ and Ti O₂,electrons spontaneously transfer from Cs₂AgBiBr₆ to Ti O₂,forming a built-in electric field from Cs₂AgBiBr₆ to Ti O₂.This can realize efficient spatial separation of photogenerated carriers,and achieve excellent photocatalytic performance.It was found that the Cs₂AgBiBr₆/Ti O₂heterojunction treated at 200℃had the best photocatalytic activity,and its type was S-scheme.After 80 minutes of simulated sunlight irradiation,the degradation rate of tetracycline hydrochloride reached 92.83%,which was 1.35 times that of pure Ti O₂.This study provides an effective approach for developing efficient titanium-based oxide photocatalysts that combine high photon absorption and charge extraction.