Poly-(Imidazolium-Methylene) Chloride Mediated Self-Assembly Strategy to Modulate Electronic Structure of Carbon Nitride for Enhanced Visible-Light Photocatalytic Hydrogen Evolution

As an attractive metal-free conjugated polymer, graphitic carbon nitride (g-C3N4) has attracted extensive attention in the field of solar energy conversion and storage as a visible light responsive hydrogen evolution. However, the photocatalytic efficiency of g-C3N4 still has great room for improvement. Herein, a highly efficient visible-light-driven okra-like tubular g-C(3)N(4)photocatalyst (TCNMCA-PImM) was synthesized via pyrolysis of a poly-(imidazolium-methylene) chloride (PImM)-mediated molecular assembly prepared by a hydrothermal process of a solution containing PImM, melamine, and KOH, in which PImM acts as an electronic structure regulator owing to its strong hydrogen bond, pi-pi interaction, and van der Waals force. On the basis of maintaining tri-s-triazine structure, the increase of graphitic N promotes the separation and transfer efficiency of photogenerated electrons and holes through the electron structure adjustment. The photocatalyst displays the notably promoted photocatalytic performance for H-2 generation under visible-light illumination. The optimized photocatalyst shows 1902 mu mol h(-1) g(-1) of hydrogen evolution rate, which is 25.7 times higher than that of bulk g-C3N4. The developed polymeric carbon nitride with unique geometric structure and electronic properties can be extended to other applications like CO2 capture for carbon neutralization strategy.