Development of composite optical waveguide based on azobenzene-modified titanium metal-organic framework film for study of gas adsorption kinetics.

This study investigates the fabrication and gas adsorption kinetics of an azobenzene (AZB)-modified titanium metal-organic framework (AZB@Ti-MOF) film composite optical waveguide (COWG) that recognizes ethylenediamine (EDA) gas. After modification with AZB, the surface of the Ti-MOF film became rough and evolved from a hemispherical structure to a petal-like structure; a large pore size and small specific surface area accompanied the evolution of the surface morphology. The AZB@Ti-MOF film COWG exhibited a positive response to EDA gas co-existing with the same concentration (1000 ppm) of benzenes, amines, and acidic gases.