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

Abstract 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 minutes 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.