| Two-dimensional(2D)materials have attracted wide attention in catalysis,energy storage and other fields due to their different physicochemical properties and unique structural characteristics.2D structures can not only improve the specific surface area,reactivity and active sites of materials,but also promote mass transfer,light scattering and trapping.Among many preparation methods,the biotemplate method combines biomaterials with inorganic materials to prepare more advanced functional materials using natural biomaterials as templates.In this paper,2D porous Bi2O3 nanosheets were prepared by chemical liquid impregnation method using petals as natural biotemplate and bismuth nitrate as raw material.The effects of bismuth nitrate concentration,impregnation time,impregnation temperature and calcination temperature on the morphology of Bi2O3 nanosheets were discussed.Thermogravimetric analysis(TGA),differential scanning calorimetry(DSC),Fourier transform infrared spectroscopy(FT-IR),X-ray diffraction(XRD),scanning electron microscopy(SEM),transmission electron microscopy(TEM),energy spectrum analysis(EDS),specific surface area measurement analysis(BET)and ultraviolet-visible diffuse reflectance spectroscopy(UV-vis DRS)were tested to analyze structure and properties of samples and its photocatalytic performance.The results showed that the original morphology of China rose petal was completely reproduced under the synthetic conditions of 0.04 mol/L bismuth nitrate concentration,12 h impregnation time,20?impregnation temperature and 550? calcination temperature.The diameter of bowl-shaped cell on the front side of sample is about 5?8 m,and the thickness of the lamella on the reverse side is about 100 nm.The crystalline phase of the prepared samples is alpha phase,the specific surface area is 45.70 m2/g and the bandgap energy is 3.10 eV.The 2D porous Bi3O3 nanosheet can degrade methylene blue(MB)solution effectively under Xenon lamp irradiation.After 3 hours,the degradation rate reaches 94.84%.The three-cycle experiment proves that the preparedcatalyst not only has good recyclability,but also has good stability.2D porous tricobalt(Co3O4)nanosheets and 2D porous zinc oxide(ZnO)nanosheets were prepared by simple impregnation method using petals as natural biotemplate and cobalt nitrate and zinc nitrate as raw materials.The results showed that the original morphology of China rose petals was completely replicated.The 2D porous Co3O4 nanosheet is spinel phase with a specific surface area of 51.36 m2/g,which is significantly higher than that of the untemplated Co3O4.The bandgap energy is 1.92 eV and 2.45 eV,the bandgap energy of 1.92 eV is derived from O2-?Co2+ charge transfer and the bandgap energy of 2.45 eV is attributed to O2-?Co3+ charge transfer.After 60 minutes irradiation by xenon lamp,the degradation rate of 2D porous Co3O4 nanosheets reaches 91.72%.The kinetics of catalytic degradation of MB,the formation mechanism and photocatalytic mechanism were analyzed.The 2D porous ZnO nanosheet is a hexagonal wurtzite with a specific surface area of 58.39 m2/g and bandgap energy of 3.09 eV.2D porous ZnO nanosheets can effecti vely degrade MB solution under the irradiation of xenon lamp,the degradation rate reaches 90.40%after 140min,which is significantly higher than that of ZnO without template. |
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