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

Hollow double-shell Cu 2 O@CuCo 2 O 4 (HDS-Cu 2 O@CuCo 2 O 4 ) Z-Scheme photocatalyst with a porous structure was designed and successfully synthesized by anchoring Cu 2 O nanoparticles (NPs) on the surface of CuCo 2 O 4 hollow spheres in situ. HDS-Cu 2 O@CuCo 2 O 4 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-Cu 2 O@CuCo 2 O 4 for CTC degradation, which is 1.7 and 2.1 times higher than that of pristine Cu 2 O and CuCo 2 O 4 . 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-Cu 2 O@CuCo 2 O 4 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.