Microstructure regulation of graphitic carbon nitride nanotubes via quick thermal polymerization process for photocatalytic hydrogen evolution.

• The thermal polymerization of g-C 3 N 4 nanotubes is extremely shortened to 5 min. • The formation of nanotubes is directly related to the polymerization temperature. • The photocatalytic H 2 production of g-C 3 N 4 nanotubes is improved more than 7 times. • For g-C 3 N 4 nanotubes, long-time thermal polymerization process is unfavorable. • This work provides novel insights into the preparation of g-C 3 N 4 nanotubes. Among multitudinous photocatalytic materials, graphite carbonitride (g-C 3 N 4) has been widely explored as a new photocatalyst. The g-C 3 N 4 nanotubes with hollow one-dimensional structure can promote carrier migration along the one-dimensional direction, thereby improving the electron-hole separation efficiency, which has always been a hot spot. However, the collapse of nanotubes in long-term thermal polymerization process leads to the decline of photocatalytic performance, which is expected to be further optimized. Herein, we report g-C 3 N 4 nanotubes (TCN) through short time thermal polymerization to ensure the integrity of g-C 3 N 4 skeleton. And the influence of thermal temperature on the internal formation mechanism of nanotube morphology is investigated. Combined with the unique hollow tube structure and complete framework, the migration of photogenerated carriers is significantly accelerated and the photocatalytic hydrogen evolution performance is improved more than 7 times compared with the original g-C 3 N 4. This work provides novel insights into the preparation of g-C 3 N 4 nanotubes for photocatalytic applications. [ABSTRACT FROM AUTHOR]