Metal-organic frameworks (MOFs) and covalent organic frameworks (COFs) offer significant potentials in molecular separation, with implications for energy and climate change, especially in the separation of H2, CO2, and ions. We have pioneered the crystallization of ultra-thin 2D zeolitic imidazolate frameworks (ZIF) films, demonstrating unprecedented H2 flux. Now, we've synthesized 2D films of MOFs such as UiO-66, UiO-66-NH2, and Zn2(bim)4, alongside COFs, achieving superior molecular separation. However, their crystal structure remains undetermined. This proposal seeks beamtime to elucidate the structures of these newly synthesized 2D films using advanced techniques previously successful at the BM01 facility of ESRF. Additionally, we aim to explore the novel heterostructured 2D ZIF/COF film, emphasizing the substrate's role in defining 2D film structures.