An in situ self-assembled Cu4I4–MOF-based mixed matrix membrane: a highly sensitive and selective naked-eye sensor for gaseous HCl

The Cu4I4-MOF-based mixed matrix membranes (MMMs) can be readily prepared by one-step in situ self-assembly of a tri-armed oxadiazole-bridged ligand and CuI in polymer binder solution under ambient conditions. The visual and luminescent HCl(g) sensing detecting limits of the resulting Cu4I4-MOF-based MMMs are 3.2 and 1.6 ppb, respectively, and the response time is less than 1 min.