Novel engineering of single-metals (TM: Cr, Mo, W) chemical tailoring of Pt-encapsulated fullerenes (Pt@C59TM) as dual sensors for H2CO and H2S gases: A theoretical study

This theoretical study explores the novel engineering of group 6 transition metals (Cr, Mo, W) functionalized Pt-encapsulated fullerenes (Pt@C59TM) as dual sensors for H2CO and H2S gases. Using appropriate density functional theory (DFT) calculations at the PBE0/GenECP/Def2svp/LanL2DZ method, the research investigates the adsorption characteristics and sensing capabilities of Pt@C59TM complexes. Various analyses, including adsorption energy, molecular dynamics, electronic structure, and thermodynamics among others, are employed to assess the interactions between the sensor surfaces and target gases. The study reveals unique reactivity patterns, with Pt@C59W identified as the most responsive (reactive) surface with an Nmax value of 7.056 eV. Additionally, insights into the stabilization mechanisms revealed that stabilization further increased after the adsorption of the gases. Due to the nucleophilic nature of the gases, the Pt@C59W surface showcased the highest adsorption energy for both gases (-590.849 kcal/mol for H2S and -525.629 kcal/mol for H2CO). The negative values of the entropy change (ΔS) for all the systems further ascertain the values of the adsorption energy, indicating that the interaction between the adsorbent and the adsorbate is chemisorption. The sensing dynamics of the systems denoted a work function value increasing for all complexes with a moderate recovery time, necessitating an excellent H2S and H2CO gas sensor materials. Two materials, H2S-Pt@C59W and H2CO-Pt@C59W, showed significantly higher levels of FET (Fraction Electron Transfer) compared to others. These values, 0.000377 and 0.003101, respectively, suggest that these materials strongly bind and are very stable during the adsorption process. The non-covalent interactions contribute to a comprehensive understanding of the engineered sensor materials. This theoretical exploration provides a foundation for the design and development of highly efficient dual sensors for H2CO and H2S gases, with potential applications in environmental monitoring and industrial safety.