Metals (B, Ni) encapsulation of graphene/PEDOT hybrid materials for gas sensing applications: A computational study

Recent attention has been directed towards the role of greenhouse gases, including methane (CH₄), carbon dioxide (CO₂), and ammonia (NH₃), in driving climate change and global warming by trapping heat within the Earth's atmosphere. This has ignited an escalating interest amongst researchers to devise sensor materials capable of efficiently detecting and monitoring these gases. Herein, a novel interface material composed of boron (B) and nickel (Ni) encapsulated within a graphene/PEDOT matrix (B_Ni@GP_PEDOT) was subjected to comprehensive simulations employing density functional theory (DFT) at the B3LYP-GD3(BJ)/Def2-SVP level of theory. The primary objective of these simulations was to assess the potential of B_Ni@GP_PEDOT in detecting and capturing targeted ruminant gases. The outcomes of molecular dynamics simulations unveiled a favourable interaction between B_Ni@GP_PEDOT and all three gases, with CO₂ displaying the strongest attractive interaction. Interestingly, these simulations also revealed a substantial rise in system temperature during the interaction, indicative of significant energy transfer from the gases to the solid structure. Furthermore, an insightful evolution in the band gap of the system was observed, signifying increased stability. Specifically, the sequence B_Ni@GP_PEDOT_NH₃ < B_Ni@GP_PEDOT_CH₄ < B_Ni@GP_PEDOT < B_Ni@GP_PEDOT_CO₂ was established, corresponding to ascending energies of 1.30 < 1.49 < 1.72 < 1.78 eV, respectively. Intriguingly, a comprehensive analysis of the mechanistic adsorption behaviour of the studied gases indicated varying degrees of energy for adsorption: B_Ni@GP_PEDOT_CH₄ < B_Ni@GP_PEDOT_CO₂ < B_Ni@GP_PEDOT_NH₃, corresponding to energies of -0.273, -0.191, and -0.047 eV, respectively. The nature of the interaction between the adsorbent and adsorbates was meticulously explored using Quantum Theory of Atoms in Molecules (QTAIM) and Non-Covalent Interaction (NCI) analysis, yielding outcomes that perfectly aligned.