Fabrication of CuO/ZnO heterojunction photocatalyst for efficient photocatalytic degradation of tetracycline and ciprofloxacin under direct sun light

The increased use of antibiotics and their discharge into the environment contaminates drinkable water, and hence, it is highly desired to develop an efficient methodology for eradicating antibiotics from water. In this investigation, sun-light driven photocatalyst CuO/ZnO heterojunction has been constructed via hydrothermal method. The chemical composition, and morphological and optical characteristics of the fabricated heterojunction catalysts were explored by various sophisticated techniques. Comprehensive studies revealed that the CuO/ZnO heterojunction photocatalyst demonstrated exceptional photocatalytic activity for decomposing tetracycline (TC) and ciprofloxacin (CIP) antibiotics in sunlight, in contrast to pristine CuO and ZnO nanoparticles. With CuO/ZnO heterojunction, 94% tetracycline and 93% ciprofloxacin antibiotics were removed within 50 min with rate constants of 0.0371 min−1 and 0.0462 min−1, respectively. Experimental studies were conducted with the help of UV–visible spectrophotometer and LC-MS technique to observe the change in concentration of antibiotics with time and to identify the intermediates formed during degradation reaction. The obtained results verified the formation of an excellent sun-light activated heterojunction for removal of toxins from wastewater.