Design of porous double-shell Cu2O@CuCo2O4 Z-Scheme hollow microspheres with superior redox property for synergistic photocatalytic degradation of multi-pollutants

Abstract Hollow double-shell Cu2O@CuCo2O4 (HDS-Cu2O@CuCo2O4) Z-Scheme photocatalyst with a porous structure was designed and successfully synthesized by anchoring Cu2O nanoparticles (NPs) on the surface of CuCo2O4 hollow spheres in situ. HDS-Cu2O@CuCo2O4 exhibited remarkable photocatalytic activity towards chlorotetracycline (CTC) oxidation and nitrobenzene (NB) reduction under visible light irradiation. Total organic carbon (TOC) removal of 63% was achieved over HDS-Cu2O@CuCo2O4 for CTC degradation, which is 1.7 and 2.1 times higher than that of pristine Cu2O and CuCo2O4. Moreover, the photocatalytic activity for both oxidation and reduction were simultaneously improved in CTC + NB mixed system owing to the presence of the synergistic photocatalytic effect. The superior photocatalytic performance of HDS-Cu2O@CuCo2O4 hybrid system should be mainly attributed to the unique hollow structure as well as the Z-scheme charge transfer pathway, which not only improve the utilization of visible light but also enhance the separation efficiency of photoexcited charge carriers. The proposed strategy provides an insight into the application of hollow Z-Scheme photocatalyst in environmental remediation.