Mechanistic insight into photocatalytic degradation of antibiotic cefadroxil by 5 % barium/zinc oxide nanocomposite during water treatment

Photocatalytic degradation of emerging water contaminant antibiotic cefadroxil was studied at 254 nm and pH values (4.0 to 9.0) using pristine zinc oxide nanoparticles (PZONPs) and 5% barium/zinc oxide nanocomposite particles (BZONPs) as photocatalyst. These semiconductor materials were synthesized by chemical precipitation method. Photocatalyst materials were characterized and analyzed by different sophisticated techniques. Photo-generated electron-hole pair mechanism was projected based on experimental data and results. Photocatalyst materials are found to be uniform and homogeneous with closely aggregate oval in shape. The smaller average crystallite size of 5% BZONPs increases the rate of photodegradation of cefadroxil. The effects of different parameters such as variation in [cefadroxil], [photocatalyst], different dosages of photocatalyst, variation in pH, and variations in light intensity on the rate of mineralization of cefadroxil were studied thoroughly. The rate of photodegradation of cefadroxil increases with initial increase in the [cefadroxil]. The rate of photodegradation of cefadroxil was found higher in neutral and basic conditions than acidic condition. Experimental results show that the rate of photodegradation of cefadroxil was found to be increased initially with increase in the dosage of 5% BZONPs. The rate of photodegradation was found to be increased with increase in percentage doping of barium from 1 to 5 % (mole ratio). The experimental data reveals that the rate of photodegradation increases with increase in light intensity. A 5% BZONPs is a potential and efficient photocatalyst for the photodegradation of emerging water contaminant cefadroxil under UV illumination and at fixed pH.