Synergetic enhancement effect of MOF-derived porous ZnO/ Co3O4 cage Z-scheme heterostructure for high-performance photodegradation

Using solar energy for photocatalytic degradation of pollutants is a clean and effective method for treating the increasingly severe problem of environmental pollution. Herein, porous ZnO/Co 3 O 4 cages with improved charge separation ability was designed via a facile ZIF-8@ZIF-67-derived approach for tetracycline (TC) photodegradation. Great photodegradation performance and good stability were achieved. The degradation rate was as high as 97 % within 60 min. The enhancement mechanism of TC photodegradation was investigated. The porous structure of ZnO/Co 3 O 4 produced a number of active sites. The effective utilized spectrum was extended from the ultraviolet to the red region. The presence of two mixed valence states of Cobalt, Co 2+ and Co 3+ , increased the density of defect states and was conducive to the adsorption of TC. The composite had a Z-scheme heterojunction, in which strong oxidative capacity can be maintained, combination of electrons and holes was greatly reduced and efficient charge transfer occurred. This study would give new insights into the design of new photocatalysts with synergetic enhancement effect for TC photodegradation.