Fabrication of carbon bridged g-C3N4 through supramolecular self-assembly for enhanced photocatalytic hydrogen evolution

Carbon bridged graphitic carbon nitride (g-C3N4) was prepared by a facile supramolecular self-assembly method. Experimental results and theoretical calculations indicate C atoms were introduced into the g-C3N4 lattice by substituting the bridged N atoms. As a result, the delocalized big π bonds can be formed among the adjacent heptazine rings, which could both enhance the light absorption and promote the charge separation. Beneficial from the efficient charge separation and enhanced light absorption, the carbon bridged g-C3N4 exhibits high efficient photocatalytic activity, where the H2 evolution rate is about 7 times as high as that of pristine g-C3N4. This work demonstrates carbon bridged C3N4 can be fabricated by a simple supramolecular self-assembly process, which could be useful for the further development of high efficient g-C3N4 photocatalysts.