Photocatalytic Properties of Graphdiyne and Graphene Modified TiO2: From Theory to Experiment

The chemical structure and electronic properties of two-dimensional (2D) carbon-supported TiO2, TiO2-graphdiyne, and TiO2-graphene composites have been studied by first-principles density functional theory. Calculation results show that TiO2(001)-graphdiyne composites possess superior charge separation and oxidation properties, having the longest lifetimes of photoexcited carriers among all of the 2D composites containing TiO2 of different facets. Our experimental results further proved that TiO2(001)-graphdiyne composites could be a promising photocatalyst. For photocatalytic degradation of methylene blue, the rate constant of the TiO2(001)-graphdiyne composite is 1.63 +/- 0.15 times that of the pure TiO2(001) and 1.27 +/- 0.12 times that of the TiO2(001)-graphene composite.