A supramolecule-based shape-controllable preparation of carbon nitride nanotubes for the visible light driven photodegradation

The particle size and morphology of g-C3N4 significantly affect its photocatalytic performance. However, achieving a fine control over them remains a challenge. Herein, we report a supramolecule-based approach for the synthesis of a g-C3N4 nanotube photocatalyst with high activity under visible light. The ratio of free melamine to melamine-cyanuric acid supramolecule in the precursor mixtures was controlled by adding different amounts of HCl during hydrothermal reaction, which have been shown to be critical for the morphological engineering of the final pyrolyzed g-C3N4 products. Remarkably, as the amount of HCl was increased, the number of g-C(3)N(4)nanotubes increased and the diameter of the nanotubes decreased until the nanotubes broke down to form nanosheets. The photocatalytic performance of the obtained material was evaluated by employing it in the degradation of Rhodamine B. The reaction rate of the optimized sample was 14.7 times that of g-C3N4 prepared by the conventional method, which could be ascribed to the large specific surface area (77.13 m(2) g(-1)) and suppressed recombination of the photogenerated carriers owing to the special morphology of the g-C(3)N(4)nanotubes. Furthermore, its stability was confirmed by cyclic experiments, and its photocatalytic mechanism was discussed based on active species trapping experiments.& nbsp;& nbsp;