Designing 3D magnetic peony flower-like cobalt oxides/g-C3N4 dual Z-scheme photocatalyst for remarkably enhanced sunlight driven photocatalytic redox activity

Abstract

In this study, a novel 3D magnetic Co3O4@CoO/g-C3N4 ternary hybrid possessing double Z-scheme mechanism has been designed and architected by wet-impregnation and subsequent controlled oxidation process. In the Co3O4@CoO/g-C3N4 ternary hybrid system, g-C3N4 ultrathin nanopieces uniformly dispersed on each nanopetal of peony flower cobalt oxides, which not only helps to enhance the light absorption efficiency and avoid the aggregation but also readily promote the separation of photo-induced charge. Benefiting from the special hierarchical architecture, large open space between nanopetals and the synergistic effect between cobalt oxides and g-C3N4, when employed as photocatalyst for reduction of nitrobenzene (NB) and degradation of tetracycline (TC), 3D Co3O4@CoO/g-C3N4 exhibited superior redox reactivity. Notably, a double Z-scheme heterojunctions and well matched band structures could further facilitate effective charge transfer. Meanwhile, Co3O4@CoO/g-C3N4 ternary hybrids also exhibited excellent magnetic separation property and super cycling stability after four cycles, which make it a promising candidate as a visible light photocatalyst for practical application.