Zinc oxide-coated carboxyl-riched graphene oxide efficiently degrades microcystin-leucine arginine and antibiotics under visible light

Microcystin-leucine arginine (Mc-LR) and antibiotic residual in water bodies threaten human health and necessitate the development of efficient processing scheme. Photocatalytic composites are promising alternatives for eliminating these hazardous substances. Herein, we prepared a nanohybrid composed of zinc oxide (ZnO) and carboxyl-riched graphene oxide (cGO). The sustainable material termed ZnO@cGO rapidly degraded Mc-LR (k = 0.68 min-1, t(1/2) = 1.02 min, pH 7) under visible light. Mc-LR degradation products were nontoxic to human L0-2 cells. Animal experiments revealed that oral administration of Mc-LR impaired the hepatic function and caused mice death, which could be inspiringly relieved once the toxin was processed by ZnO@cGO. Furthermore, ZnO@cGO efficiently degraded three quinolone antibiotics, ciprofloxacin (k = 2.30 min(-1), t1/2 = 0.30 min), ofloxacin (k = 2.11 min(-1), t(1/2) = 0.33 min), and norfloxacin (k = 0.94 min-1, t(1/2) = 0.74 min) at pH 7 under visible light. Owing to the antibiotic removal, ZnO@cGO dramatically suppressed the development of drug resistance of sensitive bacteria. This study characterizes an easy-to-produce photocatalysed nanohybrid to eliminate Mc-LR and antibiotics in water that enriches the existing measures for water detoxication and benefits environmental improvement.

Automated summary

In this study, a nanohybrid composed of zinc oxide and carboxyl-riched graphene oxide was prepared, which could efficiently degrade microcystin-leucine arginine and three quinolone antibiotics in water. The material was non-toxic to cells and could alleviate the damage caused by the toxins to animals.