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

Abstract

AbstractAs 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‐C3N4photocatalyst (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, π‐π 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 H2 generation under visible‐light illumination. The optimized photocatalyst shows 1902 μmol 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.