Ionic liquid‐assisted synthesis of porous BiOBr microspheres with enhanced visible light photocatalytic performance

Abstract

Porous BiOBr microspheres have been successfully synthesized through an ethylene glycol‐assisted solvothermal method using reactive ionic liquids as templates and reactants during the synthetic process. The obtained samples were characterized using X‐ray diffraction, scanning and transmission electron microscopies and X‐ray photoelectron, energy‐dispersive X‐ray, Fourier transform infrared, diffuse reflectance and photoluminescence spectroscopies. The photocatalytic activities were evaluated using the degradation of rhodamine B and tetracycline under visible light irradiation. The photocatalytic efficiency of BiOBr photocatalyst synthesized using single‐molecule ionic liquid as template is better than that of BiOBr obtained using polyionic liquid as template. A possible photocatalytic mechanism is also provisionally proposed. And the degradation rate using BiOBr‐IL‐1 was 2.74, 1.24 and 4.84 times higher than that using BiOBr‐IL‐2, BiOBr‐IL‐3 and BiOBr‐KBr. The larger surface area and narrower energy band gap of BiOBr‐IL‐1 could improve the visible light harvesting ability and facilitate the separation of photogenerated electron–hole pairs and the photocatalysis process. This study affords a facile way to develop such novel photocatalysts with special morphology using ionic liquids.