Effective degradation of doxycycline by photocatalytic BiVO_4-H_2O_2 under visible light

摘要

Doxycycline (DOX) is a type of antibiotic that exists in the environment and is desired to be effectively removed. Herein, DOX was degraded by photocatalytic BiVO4-H2O2 and photocatalytic BiVO4 systems in this paper. Under the same degradation conditions, the effects of the two systems on DOX degradation were compared. The effect of the solution pH on degradation of DOX was examined in the range of 3.5-11.5. The optimum pH values were 7.5 and 11.5 for light-BiVO4-H2O2 and light-BiVO4 systems, respectively, and their removal rates were 96.27 and 98.84%, respectively. The optimum temperature of degradation was both 40 degrees C by two methods, and the removal rates were 97.03 and 53.43%, respectively. The optimum dosage of BiVO4 was both 70 mg by two methods, and the removal rates were 95.92 and 52.52%, respectively. The degradation effect by light-BiVO4-H2O2 method was better than that by light-BiVO4 method. The possible photocatalytic reaction mechanism was also discussed briefly based on ESR spectrum. DMPO trapping experiment was applied to reveal the production of hydroxyl radicals. These works provide promising constructs at dealing with the DOX water by photocatalytic degradation.