Reversible Regulation of Polar Gas Molecules by Azobenzene-Based Photoswitchable Metal–Organic Framework Thin Films

The development of tunable molecule separation membranes requires materials with remote controllability and ultra-high separation capability. In this paper, a novel photoswitchable metal organic framework (MOF) thin film (Cu2(AzoBPDC)2) was prepared by liquid phase epitaxial layer-by-layer assembly to realize the reversible remote-controlled switching. The azobenzene side groups in the Cu2(AzoBPDC)2thin film showed excellent reversible photoswitching performance under UV (365 nm) and Vis (450 nm) irradiation, achieving the remote-controlled mode of the diffusion flux of polar gas molecules in the MOF thin film.Keywords:metal–organic frameworks;azobenzene;photoswitchable;gas separation