Excellent photo- and sono- catalytic BiOF/Bi₂O₃ heterojunction nanoflakes synthesized via pH-dependent and ionic liquid assisted solvothermal method

Abstract

<div lang="en" class="abs"><p class="abs_header">Abstract</p><p>Herein, a series of BiOF/Bi₂O₃ heterojunction nanoflakes were designed. The XRD and TEM confirm that the phase structure and morphology of BiOF/Bi₂O₃ were affected by the pH value of the precursors. The catalytic activities were investigated in different catalytic ways including photocatalytic activity under ultraviolet light, photocatalytic activity under visible light and sonocatalytic activity under ultrasonic irradiation. It concluded that the catalytic performances of BiOF/Bi₂O₃ are substantially affected by laboratorial pH values. The BiOF/Bi₂O₃ prepared at lower pH values exhibited enhanced catalytic activity attributed to the favorable morphology and band gap energy. Meanwhile, it shows excellent sonocatalytic performances due to the synergistic effect of BiOF/Bi₂O₃ and H₂O₂ in sonocatalytic process. The sonodegradation efficiencies of rhodamine B reaches 95.28 % in the presence of three drops of H₂O₂ within 10 min of ultrasonic irradiation. The catalytic mechanism reveals that ·OH as the dominant active specie plays a key role in degrading the dyes both under UV light illumination and ultrasonic irradiation.</p></div>