A Graphitic-C3N4 "Seaweed" Architecture for Enhanced Hydrogen Evolution.

A seaweed-like graphitic-C3N4 (g-C3N4 "seaweed") architecture has been prepared by direct calcination of the freeze-drying-assembled, hydrothermally treated dicyandiamide fiber network. The seaweed network of mesoporous g-C3N4 nanofibers is favorable for light harvesting, charge separation and utilization of active sites, and has highly efficient photocatalytic behavior for water splitting. It exhibits a high hydrogen-evolution rate of 9900 μmol h(-1) g(-1) (thirty times higher than that of its g-C3N4 bulk counterpart), and a remarkable apparent quantum efficiency of 7.8% at 420 nm, better than most of the g-C3N4 nanostructures reported. This work presents a very simple method for designing and developing high-performance catalysts for hydrogen evolution.