One dimension: A segmented structure consisting of alternant g-C3N4 nanotubes and graphitic carbon rings (denoted as Cr-CN-NT) is successfully fabricated via chemical vapor deposition, showing ordered structure and ultralong length/diameter. Benefiting from the long-distance 1D tubular structure pathway and extended π-conjugated systems, the ultra-high average hydrogen evolution activity of Cr-CN-NT can reach 9245 μmol h−1 g−1.
The photocatalytic water splitting capability of metal-free graphitic carbon nitride (g-C3N4) photocatalyst is determined by its microstructure and photoexcited electrons transfer. Herein, a segmented structure was developed, consisting of alternant g-C3N4 nanotubes and graphitic carbon rings (denoted as Cr-CN-NT). The Cr-CN-NT showed ordered structure and ultralong length/diameter ratio of 150 nm in diameter and a few microns in lengths, which promoted electron transport kinetics and elongated photocarrier diffusion length and lifetime. Meanwhile, the local in-plane π-conjugation was formed and extended in Cr-CN-NT, which could improve charge carrier density and prohibit electron–hole recombination. Accordingly, the average hydrogen evolution rate of Cr-CN-NT reached 9245 μmol h−1 g−1, which was 61.6 times that of pristine CN, and the remarkable apparent quantum efficiency (AQE) of Cr-CN-NT reached up to 12.86 % at 420 nm. This work may provide a pathway for simultaneous morphology regulation and in-plane modification of high-performance photocatalysts.Zum Volltext