From Molecular Building Blocks to Corrugated Graphitic Carbon Nitride: Chemical Origins of Structural Preference and Electronic Diversity
Year: 2026
Type: preprint
Abstract: Despite nearly two decades of intensive research, the fundamental chemical bonding responsible for the structural stability and electronic structure of graphitic carbon nitride (g-C N ) remains unresolved.In ₃N₄) rem ₄) remai particular, the interplay between π-electron delocalization and lone-pair-bearing nitrogen atoms, which simultaneously stabilizes the framework through conjugation and destabilizes it through steric repulsion, has not been established.Here, we address this long-standing question using a comprehensive moleculesto-materials approach.This strategy reveals several energetically accessible structural isomers, including hitherto unknown ones, and establishes the bonding principles governing the evolution of g-C N .We ₃N₄) rem ₄) remai demonstrate that steric repulsion between adjacent nitrogen lone pairs is the primary driving force behind framework corrugation, thereby alleviating unfavorable non-bonding N•••N interactions and dictating structural stability.Furthermore, the frontier electronic structure differs fundamentally between the two polymorphs: heptazine-based graphitic carbon nitride (h-g-C N ) is dominated by delocalized π-type ₃N₄) rem ₄) remai frontier orbitals, whereas triazine-based graphitic carbon nitride (t-g-C N ) exhibits predominantly σ-type ₃N₄) rem ₄) remai frontier states.The frontier electronic states are primarily governed by the peripheral nitrogen atoms of the heptazine and triazine units, thereby establishing their central role in chemical reactivity and electronic properties.These findings provide a unified bonding framework that resolves the long-standing ambiguity surrounding the stability and electronic structure of graphitic carbon nitride and offer a fundamental basis for the rational design of next-generation carbon nitride materials.
Source: ChemRxiv
Authors: Gaurav Jhaa, Tawfik A. Saleh
Institution: King Fahd University of Petroleum and Minerals
Language: English
Field: Energy
Domain: Physical Sciences
Open Access status: green
OpenAlex ID: W7221720973