Work

Theoretical Study of the Interaction between Graphitic Carbon Nitride and 2,6-Dichloro-1,4-benzoquinone Pollutants: Environmental Applications

Year: 2026

Type: article

Abstract: High Resolution Image Download MS PowerPoint Slide Halobenzoquinones (HBQs) are an emerging class of disinfection byproducts of growing environmental concern due to their high toxicity and persistence in aquatic systems. In this work, we investigate the adsorption behavior of 2,6-dichloro-1,4-benzoquinone (DCBQ) on two phases of graphitic carbon nitride─triazine-based (t-g-C 3 N 4 ) and tri-s-triazine-based (h-g-C 3 N 4 )─combining Grand Canonical Monte Carlo (GCMC) simulations with first-principles density functional theory (DFT) calculations. GCMC was employed to identify the most probable adsorption configurations and competitive water coadsorption under realistic aqueous conditions. The results reveal that h-g-C 3 N 4 exhibits a significantly higher adsorption capacity and stronger affinity toward DCBQ compared to t-g-C 3 N 4, even at high water ratios, highlighting its superior selectivity for pollutant capture. DFT calculations were then applied to refine the structural, energetic, and electronic properties of the selected configurations. Both g-C 3 N 4 phases exhibit physisorption-driven interactions with DCBQ, accompanied by band gap modulation and the emergence of molecular states near the Fermi level. Noncovalent interaction (NCI) and reduced density gradient (RDG) analyses further demonstrate that adsorption is governed primarily by dispersion forces and π–π interactions. Additionally, isolated dimer calculations show that DCBQ molecules can stabilize one another through favorable noncovalent contacts, supporting the cooperative adsorption behavior observed in GCMC simulations. Overall, our results provide a comprehensive multiscale description of DCBQ adsorption on g-C 3 N 4 and reveal that h-g-C 3 N 4 is a promising candidate material for the selective capture of halobenzoquinones in aqueous media. This study advances the understanding of pollutant–surface interactions and contributes to the development of nanostructured adsorbents for water purification applications.

Source: ACS Omega

DOI: 10.1021/acsomega.5c12928

Authors: Sara Ruth Ramos Rocha, Nailton Martins Rodrigues, Michael González-Durruthy, Silvete Guerini

Institutions: Universidade do Porto, Rede de Química e Tecnologia, LAQV Requimte, Universidade Federal do Maranhão

Language: English

Topic: Adsorption and biosorption for pollutant removal

Subfield: Water Science and Technology

Field: Environmental Science

Domain: Physical Sciences

SDG: Clean water and sanitation

Open Access status: gold

Estimated APC paid: $1,935