Therefore, an electron dose rate of more than 2.0 e -Å -2 s -1 was not considered, as this would reduce the measurement accuracy of the critical dose of high index planes and increase the error bar. To examine how the choice of support material for ZIF-8 on the TEM grid (i.e., substrate) affects the results, we replaced the standard holey carbon with single-layer graphene, which offers improved electron conductivity . Fig. (a) also presents the effect of graphene as a substrate on the critical dose of {110} and {431} Bragg plane of ZIF-8, at 200 kV and 300 kV with a constant dose rate of 1 e -Å -2 s -1 . There is no significant effect on the critical dose of different planes when graphene is used as TEM substrate material.