BiOI nanosheet photocatalysts with different Er3+ doping contents were rapidly synthesized by microwave-assisted solvothermal method using water and ethylene glycol as a mixed solvent. All synthesized photocatalysts were characterized by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDX), N-2 adsorption, photoluminescence (PL) spectra, and UV-vis diffuse reflectance spectroscopy (DRS). The photocatalytic activities of the as-prepared Er3+-doped BiOI nanosheets were investigated by the photodegradation of Rhodamine B (RhB) dye in aqueous solution under visible light irradiation. The photodegradation results indicate the optimal doping of 1 mol.% Er3+ in BiOI nanosheets (doping content is from 0 mol.% to 4 mol.%) to be the most beneficial for photodegradation of RhB. 1Er-BiOI nanosheets also possesses good photocatalytic activity for representative anionic methyl orange (MO). From the scavenger testing results, the reactive species of holes (h(+)) and superoxide radical anions (O-center dot(2-)) show major impacts on the photodegradation progress of RhB and MO dyes over 1Er-BiOI photocatalyst under visible light irradiation. (C) 2018 Published by Elsevier B.V. on behalf of The Society of Powder Technology Japan. All rights reserved.