Functional group chemistry as a determinant of graphitic carbon nitride nanosheet dispersibility: A molecular dynamics study

• SO 3 H and COOH groups enhance g-C 3 N 4 exfoliation in DMF via reduced free energy. • Functionalization modulates solvent mobility/dipole interactions, affecting exfoliation. • CHO groups hinder exfoliation by increasing free energy and solvent disruption. • COOH-functionalized g-C 3 N 4 shows superior dispersibility in DMF (experimentally validated) • Solvent selection guidelines optimize functionalized g-C 3 N 4 nanosheet production. This study contributes to addressing the challenges in producing high-quality graphitic carbon nitride (g-C 3 N 4 ) nanosheets through liquid-phase exfoliation (LPE), by investigating the impact of chemical functionalization. Utilizing molecular dynamics simulations, functionalization with sulfonic (SO 3 H), carboxyl (COOH), amine (NH 2 ), hydroxyl (OH), and aldehyde (CHO) is explored to assess their impact on LPE efficiency in DMF. Our findings reveal that SO 3 H and COOH functional groups significantly enhance exfoliation efficiency by improving solvent-nanosheet interactions, decreasing solvent mobility, and reducing the free energy required for exfoliation. NH 2 and OH groups also contribute positively, though to a lesser extent, while CHO hinders the process by increasing the free energy of exfoliation and disrupting solvent–solvent interactions. Experimental validation confirms the superior dispersibility of COOH-functionalized g-C 3 N 4 in DMF compared to pristine g-C 3 N 4 , aligning with computational predictions. Based on these insights, practical guidelines are proposed for solvent selection to optimize the production of functionalized g-C 3 N 4 . Molecular-level mechanisms understood from this work can facilitate the development of strategies for advancing the synthesis and utilization of g-C 3 N 4 -based materials.