Enhanced photocatalytic degradation of Rhodamine B over metal-free SiC/C3N4 heterostructure under visible light irradiation

SiC/C3N4 composites have been prepared by cooling crystallization method in this work for photocatalytic degradation. The sample with appropriate SiC/C3N4 composition(1: 50) exhibited the best performance for photocatalytic oxidation of Rhodamine B, which achieves about 2.5 times efficiency improvement compared with the sample prepared by direct mixing method, and it is also 100 times and 2.3 times than the pristine SiC powder and C3N4 respectively. We attribute the great photocatalytic improvement to the increased BET surface area, enhanced light-absorption ability, longer carriers lifetime and more effective heterostructure in SiC/C3N4 composites prepared by cooling crystallization method. In addition, the photocatalytic degradation mechanism of RhB was discussed in detail, and the accelerated charge-carrier mobility contributes to the improvement as well.