In situ construction of layered K3Ti5NbO14/g-C3N4 composite for improving visible-light-driven photocatalytic performance

A simple calcination approach was performed to synthesize layered K 3 Ti 5 NbO 14 /g-C 3 N 4 (TNCN) composites, in which g-C 3 N 4 was formed both within the interlayers and on the surface of N-K 3 Ti 5 NbO 14 . The photocatalytic activity of samples was evaluated by the visible-light photocatalytic degradation of rhodamine B (RhB). It was found that TNCN composite with a proper mass ratio of N-K 3 Ti 5 NbO 14 to g-C 3 N 4 exhibited the rapid rate of charge separation and high efficiency of light harvesting due to the synergetic effects of layered heterojunction and N doping, leading to an excellent photocatalytic activity. Especially, the in situ intercalated mono-layered g-C 3 N 4 nanosheets can significantly increase the contact area between K 3 Ti 5 NbO 14 layers and g-C 3 N 4 nanosheets for efficient charge transfer across the interface, showing the greater effect on the enhanced photocatalytic activity. The active species trapping experiments and ESR measurements were carried out to evaluate the contribution of the active species in this photocatalytic degradation process. It was revealed that both superoxide radicals ( · O 2 − ) and holes (h + ) are the main active species, while hydroxyl radicals ( · OH) made a minor contribution to the photocatalytic degradation of RhB.