Clean air is an indispensable prerequisite for human health. The capture of small toxic molecules requires the development of advanced materials for air filtration. Two-dimensional nanomaterials offer highly accessible surface areas but for real-world applications their assembly into well-defined hierarchical mesostructures is essential. DUT-134(Cu) ([Cu₂(dttc)₂]_n, dttc=dithieno[3,2-b : 2′,3′-d]thiophene-2,6-dicarboxylate]) is a metal–organic framework forming platelet-shaped particles, that can be organized into complex structures, such as millimeter large free-standing layers (carpets) and tubes. The structured material demonstrates enhanced accessibility of open metal sites and significantly enhanced H₂S adsorption capacity in gas filtering tests compared with traditional bulk analogues.