Charge separation and photocatalytic properties of BiOI prepared by ionic liquid-assisted hydrothermal method

Abstract As a prospective sunlight-driven photocatalyst, photocatalytic property of BiOI under sun light irradiation should be further boosted. In this work, IL-BiOI with enhanced charge separation rate and sunlight photocatalytic activity was prepared through a hydrothermal method with the aid of ionic liquid (IL) 1-ethyl-3-methylimidazolium hexafluorophosphate ([EMIm]PF6). The samples were studied by Brunauer-Emmett-Teller (BET) method, X-ray diffraction (XRD), UV/Vis diffuse reflectance spectroscopy (DRS), scanning electron microscopy (SEM) and surface photovoltage spectroscopy (SPS). The photocatalytic performance of the samples toward discoloration of methyl orange (MO) aqueous solution under the simulated solar irradiation was evaluated. The results reveal that IL-BiOI exhibits better photocatalytic activity than BiOI.