Noble metal (Pd, Pt)-functionalized WSe₂ monolayer for adsorbing and sensing thermal runaway gases in LIBs: a first-principles investigation

This research using the first-principles theory introduces Pd- and Pt-functionalized WSe₂ monolayers as promising materials for detecting three critical gases (H₂, CO, and C₂H₄), to evaluate the health of Li-ion battery (LIBs). Various sites on the pristine WSe₂ monolayer are considered for the functionalization with Pd and Pt atoms. The adsorption performances of the determined Pd- and Pt-WSe₂ monolayers upon the three gases are analyzed by the comparative highlight of the adsorption energy, bonding behavior and electron transfer. Subsequently, an examination of the electronic properties of these monolayers uncovers their semiconducting nature and sensing mechanisms, while the sensing responses are quantified based on variations in their bandgaps. Furthermore, the practical applications of these monolayers are confirmed by assessing their recovery properties. The findings in this study concretely serve the Pd-WSe₂ monolayer as a promising CO and C₂H₄ gas sensor, and the Pt-WSe₂ monolayer as an optimal for H₂ gas sensor. These findings not only underscore the promising sensing potential of WSe₂-based materials for indicating thermal runaway in LIBs, but also emphasize the critical importance of metal selection for surface-functionalization on the nano-surface in the gas sensing technologies.