Nitrogen vacancy/oxygen dopants designed nanoscale hollow tubular g-C3N4 with excellent photocatalytic hydrogen evolution and photodegradation

In this study, N vacancies and O heteroatoms were decorated onto hollow nanotubes carbon nitride (UMCN-3) via hydrolyzation-precipitation-calcination method to prepare high-performance photocatalyst for hydrogen evolution and photodegradation. Plenty of hollow nanotubes with diameter of 30–50 nm endowed UMCN-3 with abundant active sites and high charge transfer efficiency. Nitrogen vacancies/oxygen dopants not only created defect states but also acted as trapping centers, thus triggering the charge rearrangement to obtain high electronic transport efficiency, as evidenced by experimental results and theoretical calculations (DFT). The hydrogen evolution rate of optimal UMCN-3 sample was 23-times higher than that of pristine g-C3N4, and still at a high level in seawater. The photocatalytic degradation activity for RhB and TC of UMCN-3 also improved greatly. The superb photocatalytic performance can be put down to the three-in-one synergistic effect on N vacancies, O doped and hollow nanotubes.