Efficient solar-driven photocatalytic performance of BiOBr benefiting from enhanced charge separation rate

•[EMIm]NO3 has been employed to prepare BiOBr photocatalyst.•[EMIm]NO3 increases the specific surface area and decreases the particle size.•The photo-induced charge separation rate has been greatly increased.•The solar-driven photocatalytic activity has been greatly promoted.

In this work, novel BiOBr photocatalyst (IL-BiOBr) with enhanced solar-driven photocatalytic activity was fabricated by a facile hydrothermal method with the assistance of ionic liquid (IL) 1-ethyl-3-methylimidazolium nitrate ([EMIm]NO3). BiOBr and IL-BiOBr were characterized by the Brunauer–Emmett–Teller (BET) method, X-ray diffraction (XRD), scanning electron microscopy (SEM), high-resolution transmission electron microscopy (HRTEM), particle size analyzer and surface photovoltage spectroscopy (SPS), respectively. The results reveal that [EMIm]NO3 increases the specific surface area, decreases the particle size, and greatly enhances separation rate of the photo-induced charge of BiOBr. The photocatalytic activity of IL-BiOBr for decolorization of rhodamine B aqueous solution was evaluated. The results illustrate that the photocatalytic performance of IL- BiOBr is more than 2.3 times of that of the reference BiOBr and the possible reason was suggested.

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