Triamterene‐Grafted Graphitic Carbon Nitride with Electronic Potential Redistribution for Efficient Photocatalytic Hydrogen Evolution

Abstract

In this study, a photocatalyst with a distorted skeleton and synthesized by grafting triamterene onto graphitic carbon nitride (g-C N ) frameworks was prepared. The pteridine ring of the triamterene-based nitrogen-enriched organic structure functions as a trapped electron site owing to its inductive effect. The benzene ring in triamterene plays an important role in the even dispersion of electrons by a conjugative effect. Redistribution of the intramolecular electronic potential is caused by a synergistic effect between the pteridine and benzene rings of triamterene and promotes separation and migration of the photoinduced charge carriers. After coupling with triamterene, the π electrons of g-C N are relocated; that is, the intrinsic electronic and band structures of g-C N are effectively modulated. The modified polymeric photocatalyst shows a high photocatalytic H evolution rate of 157.5 μmol h , a value that is 4.3 times higher than the H evolution rate of pristine g-C N (36.8 μmol h ), with an apparent quantum efficiency of 9.7 % at λ=450 nm. The incorporation of triamterene into the g-C N frameworks significantly expands its π-delocalized system by redistribution of the electronic potential, expands the visible-light absorption range, and effectively promotes the separation and migration of photoinduced charge carriers. This strategy may provide a reference for promoting charge separation of g-C N through redistribution of the electronic potential and for synthesizing novel carbon nitride based semiconductors for efficient solar energy conversion into hydrogen.

Delocalization of π‐Electron in Graphitic Carbon Nitride to Promote its Photocatalytic Activity for Hydrogen Evolution

“…In order to explore the charge transmission between UCN and AB or APy, electrochemical impedance spectroscopy (EIS) of the above samples in the dark was studied and the spectra are depicted in Figure d. It can be observed that UCN‐APy exhibits the smallest radius, representing the smallest charge transfer resistance, followed by UCN‐AB and UCN. This is in line with the above data.…”

Molecular engineering for constructing a D–A system and enhancing delocalization in g-C3N4 with superior photocatalytic activity

“…More importantly, an additional peak for UCN-5TDA appears at $114.4 ppm, corresponding to the existence of aromatic C]C from TDA. 39,40 In addition, the solid-state 1 H NMR spectra of UCN and UCN-5TDA were analyzed. As shown in…”

Noble Metal-Free Photocatalysts Consisting of Graphitic Carbon Nitride, Nickel Complex, and Nickel Oxide Nanoparticles for Efficient Hydrogen Generation

“…Graphitic CN, a metal-free polymeric photocatalyst, is formed by repeating triazine units with π-conjugated systems. − In view of the unique electronic and optical properties ( E g = 2.7 eV, active under ultraviolet and a portion of visible light), high thermal, chemical, and optical stability, graphitic CN has been demonstrated to be an outstanding visible-light-driven photocatalyst to generate hydrogen from water. During the photocatalytic process, cocatalysts based on noble metals such as Pt and Pd, are usually necessary to promote the separation of photogenerated carriers and reduce the hydrogen evolution overpotential. , Consequently, various strategies, such as controlling morphologies, combining with molecular dopants, or constructing heterojunction structures, − have been approved to enhance the photocatalytic activity of CN. Nevertheless, the utilization of noble metals still suppresses the application of CN for hydrogen generation.…”