A DFT study of superior adsorbate–surface bonding at Pt-WSe2 vertically aligned heterostructures upon NO2, SO2, CO2, and H2 interactions
Aditya Kushwaha, Neeraj Goel
Abstract
Abstract This study investigates the potential of platinum (Pt) decorated single-layer WSe 2 (Pt-WSe 2 ) monolayers as high-performance gas sensors for NO 2 , CO 2 , SO 2 , and H 2 using first-principles calculations. We quantify the impact of Pt placement (basal plane vs. vertical edge) on WSe 2 ’s electronic properties, focusing on changes in bandgap (ΔE g ). Pt decoration significantly alters the bandgap, with vertical edge sites (T V-WSe2 ) exhibiting a drastic reduction (0.062 eV) compared to pristine WSe 2 and basal plane decorated structures (T BH : 0.720 eV, T BM : 1.237 eV). This substantial ΔE g reduction in T V-WSe2 suggests a potential enhancement in sensor response. Furthermore, T V-WSe2 displays the strongest binding capacity for all target gases due to a Pt-induced “spillover effect” that elongates adsorbed molecules. Specifically, T V-WSe2 exhibits adsorption energies of − 0.5243 eV (NO 2 ), − 0.5777 eV (CO 2 ), − 0.8391 eV (SO 2 ), and − 0.1261 eV (H 2 ), indicating its enhanced sensitivity. Notably, H 2 adsorption on T V-WSe2 shows the highest conductivity modulation, suggesting exceptional H 2 sensing capabilities. These findings demonstrate that Pt decoration, particularly along WSe 2 vertical edges, significantly enhances gas sensing performance. This paves the way for Pt-WSe 2 monolayers as highly selective and sensitive gas sensors for various applications, including environmental monitoring, leak detection, and breath analysis.