A Tubular g-C 3 N 4 Based Composite Photocatalyst Combined with Co 3 O 4 Nanoparticles for Photocatalytic Degradation of Diesel Oil

The photocatalysis is a very promising technique to address the serious issues of environmental pollution. Among the common photocatalysts, the graphitic carbon nitride (g-C 3 N 4 ) is widely used for the photodegradation of organic pollutants due to its proper band structure. To further improve the photocatalytic performance of g-C 3 N 4 , a novel composite photocatalyst of Co 3 O 4 /PT-C 3 N 4 has been prepared by using a one-pot calcination method, in which cobalt tetroxide (Co 3 O 4 ) nanoparticles as the cocatalyst are introduced on the surface of rectangular hollow g-C 3 N 4 substrate (PT-Co 3 O 4 ). As a result, the obtained composite photocatalyst (Co3O 4 /PT-C 3 N 4 ) delivers an excellent photodegradation performance for diesel oil under a simulated sunlight, which can improve the separation efficiency of the photo-induced electron–hole pairs. The Co 3 O 4 /PT-C 3 N 4 composite photocatalyst exhibits a high degradation efficiency of 96.27% after 2 h of visible light, which is much higher than that of the PT-C 3 N 4 photocatalyst. Moreover, the composite photocatalyst can still maintain a high photodegradation efficiency after 10 cycles, exhibiting an excellent cyclic stability. The photo-induced carriers generated by the Co 3 O 4 /PT-C 3 N 4 composite photocatalyst follow the Z-scheme heterojunction transfer mechanism. This work gives a fresh idea for the exploration of new high-performance photocatalyst for the treatment of organic environmental pollutants. Graphical Abstract