EFFICIENT VISIBLE LIGHT PHOTOCATALYTIC ACTIVITY OF g-C_3N_4/α-Fe_2O_3 COMPOSITES SYNTHESIZED VIA A REACTABLE IONIC LIQUID

摘要

g-C_3N_4/α-Fe_2O_3 composite photocatalysts have been prepared through a one-pot solvothermal process in the presence of reactable ionic liquid 1-octyl-3-methylimidazolium tetrachlorideferrate(Ⅲ) ([Omim]FeCl_4). The structure and morphology of the as-prepared g-C_3N_4/α-Fe_2O_3 composites photocatalyst were investigated by X-ray diffraction (XRD), Fourier transformer infra-red (FT-IR), X-ray energy dispersive spectroscopy (EDS), scanning electron microscopy (SEM), high-resolution transmission electron microscope (HRTEM) and UV-vis diffuse reflectance spectroscopy (DRS). During the reactive process, it was found that [Omim]FeCl_4 acted not only as Fe source but also as solvents and templates for the fabrication of a-Fe_2O_3 mi-crospheres. The photocatalytic activity of the g-C_3N_4/α-Fe_2O_3 composite photocatalyst was investigated by photo-degradation of methylene blue (MB) in the presence of H_2O_2. The g-C_3N_4/α-Fe_2O_3 composite photocatalysts showed much higher photocatalytic activity than that of the pure α-Fe_2O_3. In addition, the 5 wt. % g-C_3N_4/α-Fe_2O_3 showed the highest photocatalytic activity and the photocatalytic degradation efficiency was 99.38 %, which is higher than that of the pure α-Fe_2O_3 photocatalyst (77.88 %). A possible mechanism for the enhanced photocatalytic activity of the g-C_3N_4/α-Fe_2O_3 composite photocatalyst was also discussed.