Biomimetic synthesis of Bi2O3/Bi2WO6/MgAl-CLDH hybrids from lotus pollen and their enhanced adsorption and photocatalysis performance

Hierarchically porous Bi2O3/Bi2WO6/MgAl-CLDH hybrids were synthesized using a biotemplate route assisted with hydrothermal treatment. The obtained samples were characterized by X-ray diffraction (XRD), scanning electron microscope (SEM), electronic differential system (EDS), transmission electron microscope (TEM), Brunner-Emmet-Teller (BET), fourier transform infrared spectroscopy (FTIR), X ray photoelectron spectroscopy (XPS) and UV-vis spectra (UV-vis). It was demonstrated that the as-synthesized Bi2O3/Bi2WO6/MgAl-CLDH exhibited 3D hierarchically porous microsphere structure, which was composed of MgAl-LDH nanosheets, Bi2WO6 nanosheets and Bi2O3 and nanoparticles. The maximum adsorption capacities of Bi2O3/Bi2WO6/MgAl-CLDH toward CR and DC were 205.3 mg/g and 204.3 mg/g, respectively. These two adsorption processes all followed pseudo-second-order kinetic model. The as-prepared samples also exhibited superior catalytic activity toward CR or DC degradation under simulated sunlight irradiation due to the high charge separation ratio of Bi2O3/Bi2WO6 heterojunction, hierarchically porous structure and synergic effect of adsorption and photocatalysis.