A Novel CoO/PT-C3N4 Composite Catalyst for Photocatalytic Degradation of Diesel Oil

The photocatalysis of graphtic carbon nitride (g-C 3 N 4 ) material has been widely used for the photocatalytic degradation of organic pollutants. However, g-C 3 N 4 still has some drawbacks, such as the high recombination of photo-induced electron–hole pairs and weak absorption of light irradiation. To further improve the photodegradation performance of g-C 3 N 4 , a novel composite photocatalyst (CoO/ PT-C 3 N 4 ) has been prepared by using a one-pot calcination method, in which cobalt oxide (CoO) as a cocatalyst are introduced on the rectangular hollow substrate of g-C 3 N 4 (PT-C 3 N 4 ), The CoO/PT-C 3 N 4 composite photocatalyst delivers an excellent photodegradation performance for diesel oil under a simulated sunlight. It exhibits a high degradation efficiency of 95.92% after light irradiation for 2 h, which is much higher than that of pristine PT-C 3 N 4 . Free radical capture experiments manifest that the free radical of ·O 2− plays a major role for the photodegradation and main active radicals abide by the sequence: ·O 2−  > ·OH > h + . Moreover, the CoO/PT-C 3 N 4 composite photocatalyst delivers an excellent cyclic stability, which only degrades 8.71% photodegradation efficiency after 10 cycles. The improvement of CoO/PT-C 3 N 4 composite photocatalyst is ascribed to the formation of a heterojunction between CoO and PT-C 3 N 4 , which promotes the separation of photo-induced carriers. This work paves a new way for the exploration of photocatalyst for the organic pollutant degradation.