Fabrication And Properties Of Inorganic/ Organic Composite Supramolecular Layered Photofuntional Materials

In this work, several types of functional organic/inorganic hybrid thin film or powdered materials have been fabricated by using layered double hydroxides(LDHs) as host material and organic luminescent molecules, CdTe quantum dots as guest. The structure and morphology of the materials have been characterized by UV-Vis spectroscopy, PL spectroscopy XRD, SEM and HRTEM. In addition, we also have studied the properties and functionalities of the corresponding materials.The detailed contents are as follows:Luminescent film materials sensitive to pollutions are important to develop new types of optical sensors toward environmental detection. Herein we report organic-inorganic hybrid thin films (TFs) with reversible luminescence response to the volatile nitrobenzene (NB) using layer-by-layer (LBL) assembly of fluorescent brightener CXT and Mg-Al-layered double hydroxide (LDH) nanoparticles. The structural and surface morphology studies show that the TFs are continuous and uniform with stacking order in the normal direction of the substrate. AFM and SEM measurements indicated that the films feature periodic structure with a period of ca.25 nm as well as niform surface morphology. Moreover, the CXT/LDH TF displays a high luminescent response as a fast colorimetric chemosensor for NB vapor with a low detection limit (4.02 ppb), good regeneration and high selectivity. In addition, by combining suitable luminescent building blocks, the films can also be extended to other two-color luminescence systems, which exhibit changes in both luminescence intensity and ratiometric fluorescence upon interaction with NB vapor,suggesting that these films can serve as new types of selective solid luminescent sensor. Therefore, this work supplies a facile LBL strategy for the fabrication of TFs as selective luminescent sensor for the trace detection of NB.We have synthesized the CdTe quantum dots with DL-Mercaptosuccinic acid as stabilizer in the water phase. Furthermore, we have made a new kind of compounds with different fluorescences by means of mixing the QDs with the MgAl-NO3 LDHs. Moreover, we tested the structural and surface morphology of the new compounds and studied their microcosmic fluorescence. In addition, the CdTe-LDH UTFs were obtained via alternate assembly of CdTe QDs and LDH nannosheets on quartz substrates by using layer-by-layer (LBL) deposition technique. The CdTe-LDH UTFs show different fluorescent light and even emit white light via alternate assembly of the CXT and CdTe QDs. Finally, we also fabricated a new material based on the mixture of CdTe QDs and LDHs colloid, which displays fluorescence quenching response toward pressure effect.