Quantum Simulations for Materials Exploration and Experimental Support: Investigating H2S Sensing Capabilities of 2D MnSiO3

Quantum Simulations for Materials Exploration and Experimental Support: Investigating H2S Sensing Capabilities of 2D MnSiO3

• Autor
• Caique Campos de Oliveira
• Co-autores
• Pedro Alves da Silva Autreto
• Resumo

• Hydrogen Sulfide (H2S) is recognized as a hazardous gas due to its corrosive properties, posing a risk to human health by causing eye irritation and respiratory system damage, with lethality observed at concentrations surpassing 100 ppm. H2S is prevalent in oil refineries and wastewater, necessitating careful handling due to its capacity to corrode metal drainage systems. Consequently, precise hydrogen sulfide sensing is imperative in industrial settings. Oxide materials, characterized by environmental stability, high surface area, and tunable selectivity through defect engineering, are gaining prominence in sensing applications. Natural silicates, an emerging material class for sensing, exhibit chemical heterogeneities, including natural dopants such as transition and alkali metals. Despite the limited surface area and active sites of bulk silicates, the presence of octahedral cations with anisotropic bonds facilitates their exfoliation into thin 2D films [1].  

  Advancements in computational power have revolutionized materials discovery, investigation, and design. The collaborative synergy between experimental and theoretical approaches has burgeoned in recent years, allowing scientists from diverse fields to integrate classical and quantum calculations in materials science. This integration aids in corroborating experimental findings by modeling material surfaces, defects, doping, heterojunctions, and heterostructures, offering enhanced insights into chemical reactions and physical processes. Quantum ab-initio calculations, based on Density Functional Theory, stand as an accurate means of describing the electronic and structural properties of materials and molecules, providing a robust tool for investigating their interactions. In this study, ab-initio calculations based on Density Functional Theory were employed to explore the H2S sensing capabilities of 2D R-silicate Rhodonite, offering theoretical insights into selectivity and interaction mechanisms. 

  The ab-initio calculations were conducted using the Quantum Espresso computational package, employing the pseudopotentials approach at the PBE level [2]. Thin films of R-silicate were exfoliated on the (011) surface based on XRD experimental data. The 2D surface computational model was constructed by cleaving bulk MnSiO3 into the (011) direction, resulting in a monolayer slab. Selectivity towards H2S and CO2 was investigated by computing adsorption energies, equilibrium distances, and molecule-surface interactions, employing differential charge analysis. 

  Results indicate preferential adsorption of both H2S and CO2 on Mn sites of the (011) surface, evidenced by larger adsorption energies. A comparison of H2S and CO2 adsorption revealed a stronger binding with the surface for H2S at both Si and Mn sites, highlighting the surface's selectivity towards H2S. Differential charge analysis further supported these findings, showing greater charge accumulation for H2S absorbed into Mn sites. Our calculations also shed light on the interaction mechanism, confirming physisorption based on equilibrium distances between molecules and the surface. This study demonstrates the successful integration of DFT calculations with experiments, providing a comprehensive investigation into material properties and applications. 

  References 

  [1] Mahapatra, P. L., Singh, A. K., Tromer, R., R., K., M., A., Costin, G., Lahiri, B., Kundu, T. K., Ajayan, P. M., Altman, E. I., Galvao, D. S., & Tiwary, C. S. (2023). Energy harvesting using two-dimensional (2D) d-silicates from abundant natural minerals. J. Mater. Chem. C, 11(6), 2098–2106. https://doi.org/10.1039/D2TC04605A.  

  [2] Perdew, J. P., Burke, K., & Ernzerhof, M. (1996). Generalized Gradient Approximation Made Simple. Phys. Rev. Lett., 77(18), 3865–3868. https://doi.org/10.1103/PhysRevLett.77.3865.  

• Palavras-chave
• Gas sensing, Silicates, DFT
• Modalidade
• Comunicação oral
• Área Temática
• Materiais Funcionais Avançados