Hollow one-dimensional (1-D) nanostructures have drawn great

attention in heterogeneous photocatalysis. Herein, we report that tapered

polyacrylonitrile-derived carbon (C-PAN)/g-C3N4 composite nanotubes can be

synthesized through a facile sulfur-mediated self-templating method via thermal

condensation of polyacrylonitrile (PAN), melamine, and sulfur. The hollow tapered

C-PAN/g-C3N4 composite nanotubes exhibit superior photocatalytic H2 evolution

performance under visible light irradiation. The 5 wt % C-PAN/g-C3N4composite

nanotubes show a 16.7 times higher photocatalytic H2

evolution rate than that of

pure g-C3N4, which is even 4.7 times higher than that of a 5 wt % C-PAN/g-C

3N4

nanosheet composite obtained without sulfur. The hollow nanotubular composite

structure provides g-C

3N4

with higher specific surface area, enhanced light absorption, and better charge carrier separation

and transfer, which synergistically contribute to the superior photocatalytic activity. Our work provides a new strategy to

develop carbon-based architected photocatalysts.