Sen Li,Wei Wang,Yixing Zhao,Zhenwei Zhang,Yongyi He,Chuan Wang,Yongchun Guo,Tingfang Tian,Li Wang,Hu Liu
Zeolite A (LTA)-coated Mn-doped perovskite quantum dot CsPb1–xMnxCl3@LTA (x = 0, 0.2, 0.4, 0.6, and 0.8) composites were fabricated by vapor deposition crystallization. LTA not only improved the water, light, and thermal stability of perovskite quantum dots but also limited the average size of perovskite quantum dots to less than 20 nm. Mn2+ doping improved the exciton lifetime of a perovskite quantum dot matrix. The photogenerated carriers generated by Mn2+ have a decay life of hundreds of microseconds, which effectively improves the photocatalytic efficiency. When x = 0.6, the total yield of CO and CH4 was 1443.25 μmol g–1 (1191.08 μmol g–1 of CO and 252.17 μmol g–1 of CH4). After 5 catalytic cycles, the yields of CO and CH4 remained at 53.77% and 62.27% of their original levels, respectively, indicating that CsPb1–xMnxCl3@LTA has excellent photocatalytic application prospects.
Herein, novel catalysts of Fe-containing zeolite-A (Fe/zeolite-A) were synthesized by exchanging iron ions into zeolite-A framework, and short-chain organic acids (SCOAs) were employed as chelating agents. Reactive Brilliant Blue KN-R (KN-R) was used as a model pollutant to evaluate the performance of these catalysts based on the heterogeneous Fenton reaction. The results showed that Fe-OA/3A, which applied zeolite-3A as the supporter and oxalic as the chelating agent, presented the most prominent KN-R decolorization efficiency. Under the initial pH of 2.5, 0.4 mM KN-R could be totally decolorized within 20 min. However, the mineralization efficiency of KN-R was only 58.2%. Therefore, anthraquinone dyes were introduced to modify zeolite-3A. As a result, the mineralization efficiency of KN-R was elevated to 92.7% when using Alizarin Violet (AV) as the modifier. Moreover, the modified catalysts exhibited excellent stability, the KN-R decolorization efficiency could be maintained above 95.0% within 20 min after operating for nine cycles. The mechanism revealed that the Fe(II)/Fe(III) cycle was accelerated by AV-modified catalyst thus prompting the KN-R decolorization in Fenton-like system. These findings provide new insights for preparing catalysts with excellent activity and stability for dye wastewater treatment.
A series of novel polymer–lanthanide–zeolite A hybrid films have been synthesized by polymerization of ethyl methacrylate (EMA) and 4-vinylpyridine (4VP) containing surface modified zeolite A, inside the channels of which lanthanide complexes are incorporated. The surface modification was conducted by first functionalizing zeolite A with a multi-functional linker and then covalently grafting lanthanide ions which coordinate to both the molecular linker and the polymer chain. The SEM images suggest that lanthanide-based zeolite A particles are evenly dispersed in the polymer matrices, leading to a certain transparency of the thin films. The luminescence properties of the resulting materials were characterized in detail and the results reveal that all the materials exhibit intense emission lines upon UV-light irradiation. Various emitting colors of the zeolite A–polymer materials can be obtained by simply changing the lanthanide complexes inside and outside the channels of zeolite A. Furthermore, the white light emission from the tricolor luminous materials can be easily obtained by adjusting the different concentrations of the doped ions and the excitation wavelength.
Both Zeolite A (ZA) and two kinds of 2,2′-bipyridine-5,5′-dicarboxylic acid (H 2 bpydc) linking meta-organic frameworks (MOFs) (MOF-253 (Al(OH)(bpydc)) and UiO-67 ([Zr 6 O 4 (OH) 4 (bpydc) 6 ])) have been used to construct novel photofunctional multi-component lanthanide hybrid materials through covalent-coordination cooperative assembly. Microporous ZA is firstly functionalized by covalently grafting of the surface hydroxyl groups using special silane crosslinking reagent 3-methacryloxypropyltrimethoxysilane (MPTMS). Then the multi-component assembly are realized by coordination interaction between lanthanide ions (Eu 3+ /Tb 3+ ), ZA through the carbonyl group of MPTMS unit and MOF-253 (or UiO-67) through the double nitrogen of bpydc linker. Subsequently, the obtained multicomponent hybrid materials (ZA-MPTMS-Eu/Tb-MOF-253(UiO-67)) are characterized by means of XRD, FT-IR, SEM and especially the photoluminescence properties are studied in details. These hybrids with both ZA and MOFs host show the main characteristic crystal framework morphology of ZA together with the composition of MOFs. They display the feature luminescence of Eu 3+ /Tb 3+ ions for the energy transfer from bpydc linker of MOFs. Furthermore, ZA-MPTMS-Eu-UiO-67 hybrid material is selected to check the luminescence response to volatile substances, whose luminescence quenching is found for ammonia vapor.
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