Removal of tetracycline hydrochloride by Z-scheme heterojunction sono-catalyst acting on ultrasound/H2O2 system

Because of the unique advantages, ultrasound (US) has become a popular technology for water organic treat-ment. In order to compensate for the disadvantages of expensive equipment and large energy input caused by US, researchers combine US with iron-based sono-catalyst to realize the rapid and efficient degradation of pollutants. Aiming at the ultrasonic hot spot and sonoluminescence effect, in this work, Z-type heterojunction sono-catalyst FeII-MIL-88B/GO/P25 (FeII-MGP) was synthesized for TC-HCl removal. The physicochemical properties of the material were characterized by SEM, XRD, XPS and BET. The addition of GO contributed to the formation of the Z-Scheme heterojunction. At the optimal reaction conditions determined by influential factor experiments (ul-trasonic power of 100 W, sono-catalyst dose of 0.3 g/L, H2O2 dose of 20 mM and pH 5), in only 7 min, 83.3 % of TC-HCl was removed, and the TOC degradation efficiency reached 52.2 %. The contrast experiment demon-strated that the US/FeII-MGP/H2O2 system had the best pollutant removal performance. After three repeated experiments, the removal efficiency decreased by only 6 %. & BULL;OH was identified as the major radical from the quenching experiments and technical EPR. UV-vis and Mott-Schottky measurements suggested that the possible carrier transfer paths followed the Z-Scheme heterojunction model.