Influence of porosity and pore size on sputtering of nanoporous structures by low-energy Ar ions: Molecular dynamics study

•Presence of nanosized pores can enhance the sputtering.•Ion irradiation of nanoporous structures can cause the collapse of pores in near-surface layers.•As a result of pore collapse, a continuous solid layer is formed on the material surface.•Excess surface energy per unit volume is a key parameter to determine the probability of pore collapsing.