GIWAXS of the four UiO-66-NH2 films revealed broad peaks (Figures ) attributing to the ultrathin nature of the film. Peak intensity increased monotonically with the thickness of the film from improved scattering in the thicker films. An out-of-plane 200 texture was observed, indicating that the films were preferentially oriented along the a-out-of-plane direction. This was further corroborated by the scattering intensity along the azimuthal angle, which identified 111 facets oriented ~54.7° relative to the 200 facets, consistent with the angle between these two lattice planes in the cubic system (Figure , Supplementary note 6). Combined with XPS and AFM analysis, this confirms anisotropic in-plane growth of non-vdW 2D UiO-66-NH2 films with a thickness of just a few unit cells.