Preparation And Modification Of ZnO Nanocomposite Hollow Microspheres And Their Photocatalytic Reduction Of CO₂

ZnO/ZnGa2O₄, ZnO/Sulfide and ZnO/ZnAl2O₄/CuS nanocomposite photocatalysts were successfully synthesized. Theses as-prepared samples were characterized by TG/DTA, XRD, SEM, TEM, UV-Vis DRS, FL and BET techniques. Moreover, the effects of type and content of sulfides, concentration of photocatalyst, reaction temperature, irradiation time and concentration of sacrificial reagent on the photocatalytic reduction efficiency of CO₂ were investigated under the simulated sunlight irradiation.ZnO/ZnGa2O₄ nanocoposite photocatalysts with hollow microspheres were successfully synthesized via one-pot hydrothermal method. In addition, the samples, activity of photocatalytic reduction of CO₂ was evaluated in detail. These results showed that, the maximum reduction production of methanol（7.92 mmol·gcat-1） was obtained when the concentration of photocatalyst was 1 g·L-1, the reaction temperature was 75 °C, the irradiation time was 6 h and the mass ratio of sacrificial reagent of NaOH and Na2SO3 was 1.6:5.04.ZnO nanocoposite photocatalysts with hollow microspheres were successfully synthesized via one-pot hydrothermal method and loaded on it with different sulfides（CuS, CdS and Bi2S3） through impregnation method to form binary nanocomposite photocatalysts（ZnO/Sulfide）. After testing the activity of photocatalytic reduction of CO₂, it showed that the maximum reduction production of methanol（3.45 mmol·gcat-1） was obtained when the CuS loading content was 3%, the concentration of photocatalyst was 1.5 g·L-1, the reaction temperature was 75 °C, the irradiation time was 8 h and the mass ratio of sacrificial reagent of NaOH and Na2SO3 was 1.6:5.04.ZnO/ZnAl2O₄ nanocoposite photocatalysts with hollow microspheres were successfully synthesized via one-pot hydrothermal method and loaded on it with CuS through impregnation method to form ternary nanocomposite photocatalysts（ZnO/ZnAl2O₄/CuS）. After testing the activity of photocatalytic reduction of CO₂, its maximum reduction production of methanol（8.21 mmol·gcat-1） was obtained when the CuS loading content was 1%, the concentration of photocatalyst was 1 g·L-1, the reaction temperature was 75 °C, the irradiation time was 6 h and the mass ratio of sacrificial reagent of Na OH and Na2SO3 was 1.6:5.04.