Preparation Of UiO-66 Metal-Organic Framework Films For Vapor Sensing And Ion Transport

In recent years,MOF materials have received great attention in a variety of fields due to their large internal surface areas,uniform but tunable nanometer aperture,tailorable chemistry,and high thermal stability.In most cases,MOF materials are synthesized and used in powder form.However,some especial applications require growing MOF films on specific substrates,such as MOF-integrated molecule-size-selective separations devices,catalysis devices,sensing devices and so on.To optimize the performance of MOF-based devices,we can modulate their structural features from the microscopic and mesoscopic view and then integrate these materials into certain devices through some method,which also provides a platform for studying the relationship between material structures and properties.Herein,we introduce two integration methods of MOF film-based devices.Through the pre-synthesis and post-assembly strategy,MOF single crystal-based sensor devices with controllable microscopic and mesoscopic structural characteristics were constructed,which facilitated the performance optimization of MOF single crystal-based sensor.By in-situ growth method,dense and uniform MOF films were synthesized on the pretreated glass substrate.And the ion conduction,possible conduction mechanism through MOF films were subsequently studied.The specific work is divided into the following three aspects:(1)UiO-66 octahedral microcrystals with the tunable sizes and missing-linker defects can be obtained in large scale through the base/acid co-modulated synthesis.Subsequently,these monodispersed crystals assembled into monolayers with controllable microscopic and mesoscopic structural features.Based on the crystal size,crystal defect and mesoscopic structure of films,sensing performances of single crystal-based devices were quantitatively evaluated.(2)Through in-situ growth method,we prepared mixed-ligand UiO-66 films on PDA-modified glass substrates,studied the proton conduction and the possible conduction mechanism of films.The influence of-SO3H on the proton transport was further explored.(3)We explored the metal ions transport through UiO-66 films,analyzed the possible influence factors,and verified the possible conduction mechanism.