Optimal Structure and Photocatalytic Performance of C₃N₄@TiO₂ Composite by Controlling the Molar Ratio of Components

Based on the heterogeneous composite design of C 3 N 4 and TiO 2, composite photocatalysts of C 3 N 4 @TiO 2 (with varied molar ratios of C 3 N 4 to TiO 2 ) were synthesized by a water bath method to degrade RhB in wastewater. The composition, morphology, structure, and photocatalytic properties of the materials were assessed through a variety of characterization techniques. The results show that TiO 2 nanoparticles are uniformly coated on two-dimensional g-C 3 N 4 nanosheets, forming relatively dense heterostructures within the C 3 N 4 @TiO 2 composite. Due to the synergistic effect derived from the heterogeneous component and appropriate proportion of C 3 N 4 and TiO 2, the light absorption range is extended, and the separation/transport performance of photon-generated carrier is improved. As a result, TCNT-3 (where the molar ratio of C 3 N 4 to TiO 2 is 1:1) presents remarkable photocatalytic performance, the degradation rate of which for 60 min is 99.8%, and the reaction rate constant is calculated to be 0.0872 min –1 . Moreover, the degradation efficiency remains 94.4% after 5 cycles, indicating the superior cycle stability.