In situ embedment of CoOx on g-C3N4 as Z scheme heterojunction for efficient photocatalytic degradation of methyl orange and phenol under visible light

A facile one-step pyrolysis method was reported to construct a Z-scheme CoOx/g-C3N4 heterostructures, which exhibit obviously enhanced visible light driven photocatalytic degradation of methyl orange and other organic pollutants. The samples were characterized by XRD,TEM, SEM, N2 adsorption-desorption, UV–vis DRS and XPS, the characterization results identified that the cobalt oxide clusters were embedded on g-C3N4 via the strong interface electronic interaction between cobalt and sp2-N of g-C3N4. Photoelectrochemical analysis revealed that the charge transfer and separation of CoOx/g-C3N4 heterostructure have been greatly improved. A plausible Z scheme photocatalytic mechanism was proposed and confirmed by the radical trapping experiment results. The significantly enhanced photocatalytic performance of CoOx/g-C3N4 heterostructures than g-C3N4 can be ascribed to the Z-Scheme charge transferring mode and improved separation of photo-induced charge carriers driven by inner electric field at the interface between CoOx and g-C3N4.