Graphene oxide modified K, P co-doped g-C3N4 and CoFe2O4 composite for photocatalytic degradation of antibiotics

Background: The utilization of photocatalysts for the removal of contaminants present in aquatic systems has attracted great interest due to their promising removal efficiencies. Methods: In this work, phosphorus and potassium co-doped g-C3N4 (KPCN) was heterostructured with CoFe2O4 photocatalyst and modified with graphene oxide (GO) by using hydrothermal synthesis process (KPCN/GO/ CoFe2O4). The formation of the KPCN/GO/CoFe2O4 nanocomposite was confirmed by different characterization techniques. The KPCN/GO/CoFe2O4 nanocomposite followed the S-scheme charge transferal route. The photocatalytic activity of KPCN/GO/CoFe2O4 composite was analysed for tetracycline (TC) and doxycycline (DOX) antibiotics removal using visible light. Significant findings: KPCN/GO/CoFe2O4 showed the highest photocatalytic activity compared to g-C3N4, KPCN, and KPCN/GO photocatalysts. KPCN/GO/CoFe2O4 photocatalyst showed 85% degradation for tetracycline antibiotics within 60 min and 99% degradation for doxycycline antibiotics within 60 min. The degradation efficiencies were improved with doping and further improved by adding GO and CoFe2O4. The light-harvesting was improved by doping, GO enhanced photocatalyst adsorption capabilities and heterojunction formation improved the ability to separate charges. Heterojunction with magnetic CoFe2O4 photocatalyst also improved the separation ability and reusability of KPCN/GO/CoFe2O4 photocatalyst.