Tailoring the Morphology of g-C3N4 by Self-Assembly towards High Photocatalytic Performance

We report a novel method for the preparation of graphitic carbon nitride (g-C3N4) with various morphologies through self-assembly and calcination, which starts from the raw materials melamine, urea, and cyanuric acid. The hollow to wormlike morphologies of g-C3N4 could be readily tailored by adjusting the molar ratio of melamine to urea; with increase in the molar ratio from 3:1 to 1:3, a morphology transformation was observed. The morphologies were tailored by self-assembly of the aggregates by hydrogen bonding and ionic interactions. Correspondingly, an increased BET surface area from 49.6 to 97.4 m(2)g(-1) was observed. If used as a photocatalyst in degrading rhodamine B (RhB) under visible-light irradiation, these g-C3N4 samples demonstrated 7 to 13 times higher performance than conventional bulk g-C3N4. The high performance was attributed to the unique morphology that provided not only high specific surface area but low recombination losses of photogenerated charges.