Effect of five typical vacancy defects on the tribological behaviors of MoS2 sheet: A molecular dynamics study

[Display omitted] •Effect of vacancy defect on friction behaviors of MoS2 was studied by MD simulation.•Vacancy defects reduce the anti-friction and anti-wear properties of the MoS2 sheet.•Defects cause high atomic pinning and energy barriers at the friction interfaces.•The transformation of VS vacancy occurs under a critical normal load of 130nN. The tribological behavior of the defective MoS2 sheet has been investigated under different normal loads by molecular dynamics simulations. Five typical vacancy defects have been introduced to estimate the anti-friction and anti-wear properties of defective MoS2 sheets. The existence of vacancy defects increases the local friction of the MoS2 sheet and accelerates wear failure. The degree of vacancy defect influence on the anti-friction and anti-wear properties of MoS2 is as follows: VMo