In silico engineering of graphitic carbon nitride nanostructures through germanium mono-doping and codoping with transition metals (Ni, Pd, Pt) as sensors for diazinon organophosphorus pesticide pollutants

The extensive use of pesticides has raised concerns about environmental contamination, which poses potential health risks to humans and aquatic life. Hence, the need for a healthy and friendly ecosystem initiated this study, which was modeled through profound density functional theory (DFT) at the B3LYP-D3(BJ)/def2svp level of theory to gain insights into the electronic characteristics of germanium-doped graphitic carbon nitride (Ge@C₃N₄) engineered with nickel group transition metals (Ni, Pt, and Pd) as sensors for diazinon (DZN), an organophosphorus pesticide pollutant. To effectively sense diazinon, this research employed a variety of methodologies, beginning with the analysis of electronic properties, intermolecular investigations, adsorption studies, and sensor mechanisms. These detailed assessments revealed insightful results, as clearly indicated by their narrow energy gap and other electronic properties. Noncovalent interactions characterized by van der Waals forces were revealed predominantly by quantum atoms in molecules (QTAIM) and noncovalent interaction (NCI) analyses. Furthermore, the results of the adsorption studies, which measured the strength of the interaction between the pesticide molecules and the nanostructures, revealed favorable results characterized by negative adsorption energies of - 1.613, - 1.613, and - 1.599 eV for DZN_Ge@C₃N₄, DZN_Ni_Ge@C₃N₄, and DZN_Pd_Ge@C₃N₄, respectively. The simulated mechanism through which diazinon is sensed revealed favorable results, as observed by the negative Fermi energy and fraction of electron transfer (∆N), as well as a high dipole moment. This study also revealed that the codoping influenced the behavior of the systems, revealing that DZN_Ni_Ge@C₃N₄ was the best sensing system because of its strongest adsorption (- 1.613 eV), highest dipole moment (8.348 D), most negative Fermi energy (- 1.300 eV), lowest work function (1.300 eV), and good ∆N (- 1.558) values. This study, therefore, proposes these nanostructures for further in vitro studies seeking to sense diazinon and other pesticides to maintain healthy ecosystems.