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

Abstract

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 μmol g⁻¹ h⁻¹ across the full spectrum, which was 23% higher than that of the dispersed nanosheets (770 μmol g⁻¹ h⁻¹) due to chemisorption on the hierarchical structures and enhanced surface oxygen vacancies (OVs).