Small Molecule Adsorption on Defective Phosphorene

We perform Density Functional Theory calculations to determine adsorption energies of small gas molecules ($\mathrm{H}_2$, $\mathrm{N}_2$, NO, and CO) on defective, vacancy-laden, black phosphorene. Different configurations of single and double vacancies in the monolayer structure are considered, together with several possible adsorption sites onto them. The van der Waals interaction is considered for the exchange-correlation functional. This research aims to provide fundamental insights into how atomic vacancies can be engineered to tune phosphorene's surface reactivity, offering a broader understanding of its multifaceted applications.