Facile hydrothermal synthesis of Bi/BiOBr composites with enhanced visible-light photocatalytic activities for the degradation of rhodamine B

Bi/BiOBr photocatalysts with improved photodegradation performances were synthesized by a facile one-step hydrothermal method using ethanol–water mixed solution. The samples were characterized by X-ray diffraction, scanning electron microscopy, transmission electron microscopy, X-ray photoelectron spectroscopy, electron paramagnetic resonance spectroscopy, UV–vis diffuse reflectance spectroscopy and photoluminescence spectroscopy. The addition of ethanol results in the partial reduction of Bi 3+ ions to metallic Bi, different morphology from pure BiOBr , and the formation of oxygen vacancies. The dosage of ethanol plays a vital role in the morphologies and photodegradation performances of as-obtained Bi/BiOBr. The Bi/BiOBr photocatalysts show improved photodegradation performances, which is attributed to the high surface area, narrow band gap, and inhibited recombination of electron–hole pairs .