Understanding the hierarchical behavior of Bi2WO6 with enhanced photocatalytic nitrogen fixation activity

Hierarchical Bi2WO6 nanostructures self-assembled with planar arranged nanosheets and dispersed Bi2WO6 nanosheets were synthesized with different dosages of EG via a simple hydrothermal route. The Bi2WO6 photocatalysts were analyzed by X-ray diffraction (XRD), transmission electron microscopy (TEM), UV-vis diffuse reflectance spectroscopy (DRS) and X-ray photoelectron spectroscopy (XPS). A control experiment was conducted to test the effect of EG dosage on the growth mechanism and behavior of the highly (010) exposed hierarchical lamellar nanostructures and dispersed nanosheets. The photocatalytic nitrogen fixation rate of the hierarchical Bi2WO6 nanostructures was estimated to be 948 mu mol g(-1) h(-1) across the full spectrum, which was 23% higher than that of the dispersed nanosheets (770 mu mol g(-1) h(-1)) due to chemisorption on the hierarchical structures and enhanced surface oxygen vacancies (OVs).