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1.
Angew Chem Int Ed Engl ; 59(50): 22392-22396, 2020 Dec 07.
Artigo em Inglês | MEDLINE | ID: mdl-32885555

RESUMO

Hydrogen-bonded organic frameworks (HOFs) possess various merits, such as high porosity, tunable structure, facile modification, and ready regeneration. These properties have yet to be explored in the context of new functional HOF materials. The facile and inexpensive electrophoretic deposition (EPD) method applied in this study generated a transparent HOF film at room temperature in just 2 min and is applicable to other HOFs. The resulting film exhibited reversible electrochromism with the advantage of long cycle life (>500 cycles). More strikingly, this all-organic film could be readily regenerated (through rinsing with DMF and redeposition) and showed tunable electrochromic behavior (through low-cost postsynthetic modification) with the ability to undergo successive color changes, which is difficult to achieve with conventional electrochromic materials. An electrochromic device was manufactured to further demonstrate the application potential of the film.

2.
ACS Appl Mater Interfaces ; 12(26): 29854-29860, 2020 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-32483962

RESUMO

Developing a noncontact ratiometric luminescent temperature sensor with high sensitivity, widely available emission range, and reliable performance is a challenge in materials science. Herein, we demonstrated that this goal can be achieved by fabricating a lanthanide-functionalized hydrogen-bonded organic framework film (named the Eu@HOF-TCBP film). The unbonded carboxylic groups that existed in the structure not only enable lanthanide ions to bind with the framework for bringing dual emission but also allow for preparing a hydrogen-bonded organic framework (HOF) film through the facile electrophoretic deposition. The obtained film exhibits ratiometric temperature sensing performance in the range of 297-377 K with a maximum relative sensitivity of 5.787% K-1 and shows repeated use without sensitivity loss. Moreover, the material can be easily recycled and refabricated with consistent performance, demonstrating its unique merits of easy recyclability and regeneration as an HOF material. We believe that the reported strategies for preparing a dual-emitting HOF and fabricating a thin film will open a window for HOF applications.

3.
ACS Appl Mater Interfaces ; 10(24): 20854-20861, 2018 Jun 20.
Artigo em Inglês | MEDLINE | ID: mdl-29846055

RESUMO

A novel dual-emitting metal-organic framework based on Zr and Eu, named as UiO-66(Zr&Eu), was built using a clever strategy based on secondary building units. With the use of polymers, the obtained UiO-66(Zr&Eu) was subsequently deposited as thin films that can be utilized as smart thermometers. The UiO-66(Zr&Eu) polymer films can be used for the detection of temperature changes in the range of 237-337 K due to the energy transfer between the lanthanide ions (Eu in clusters) and the luminescent ligands, and the relative sensitivity reaches 4.26% K-1 at 337 K. Moreover, the sensitivity can be improved to 19.67% K-1 by changing the film thickness. In addition, the temperature-sensing performance of the films is superior to that of the powders, and the sensor can be reused 3 times without loss of performance.

4.
Inorg Chem ; 57(5): 2447-2454, 2018 Mar 05.
Artigo em Inglês | MEDLINE | ID: mdl-29437388

RESUMO

Temperature plays a crucial role in both scientific research and industry. However, traditional temperature sensors, such as liquid-filled thermometers, thermocouples, and transistors, require contact to obtain heat equilibrium between the probe and the samples during the measurement. In addition, traditional temperature sensors have limitations when being used to detect the temperature change of fast-moving samples at smaller scales. Herein, the carbon quantum dots (C-QDs) functionalized metal-organic framework (MOF) composite film, a novel contactless solid optical thermometer, has been prepared via electrophoretic deposition (EPD). Instead of terephthalic acid (H2BDC), 1',2',4',5'-benzenetetracarboxylic (H4BTEC) acid was employed to construct a UiO-66 framework to present two uncoordinated carboxylic groups decorated on the pore surface. The uncoordinated carboxylic groups can generate negative charges, which facilitates the deposition of film on the positive electrode during the EPD process. Moreover, UiO-66-(COOH)2 MOFs can absorb C-QDs from the solution and prevent C-QDs from aggregating, and the well-dispersed C-QDs impart fluorescence characteristics to composites. As-synthesized composite film was successfully used to detect temperature change in the range of 97-297 K with a relative sensitivity up to 1.3% K-1 at 297 K.

5.
ACS Appl Mater Interfaces ; 10(6): 6014-6023, 2018 Feb 14.
Artigo em Inglês | MEDLINE | ID: mdl-29359915

RESUMO

Engineering novel dual-emitting metal-organic frameworks (MOFs) with wide emission ranges for application as ratiometric temperature sensors is still a challenge. In this paper, two novel dual-emitting MOFs with intergrated lanthanide metals and luminescent ligand in a UiO-66-type structure, named Ln@UiO-66-Hybrid, were prepared via the combination of postsynthetic modification and postsynthetic exchange methods. Subsequently, the as-synthesized MOFs were deposited onto fluorine tin oxide substrates through electrophoretic deposition by taking advantage of the charges from the unmodified carboxylic groups of the MOFs. The as-prepared Tb@UiO-66-Hybrid and Eu@UiO-66-Hybrid films were applied to detect temperature changes. The resulting Tb@UiO-66-Hybrid film exhibited good temperature-sensing properties with a relative sensitivity of up to 2.76% K-1 in the temperature range of 303-353 K. In addition, the Eu@UiO-66-Hybrid film showed excellent temperature-sensing performance based on the energy transfer between the luminescent ligand (H2NDC) and europium ions with a relative sensitivity of up to 4.26% K-1 in the temperature range of 303-403 K.

6.
Langmuir ; 33(50): 14238-14243, 2017 12 19.
Artigo em Inglês | MEDLINE | ID: mdl-29172529

RESUMO

Until now, it has been a challenge to prepare lanthanide metal-organic framework films on traditional substrates, like zinc plate, indium oxide (ITO), and fluorine-doped tin oxide (FTO) glasses in a rapid and facile method. In this paper, continuous and dense Ln-BTC MOFs films on unmodified low-cost substrates have been rapidly and easily fabricated though the newly developed electrophoretic deposition (EPD) method in 5 min. Moreover, the as-prepared luminescent films were successfully used for the detection of nitrobenzene (NB), trinitrotoluene (TNT) in gas phases, as well as NB, Cr3+ ions for detection in solution.

7.
Chem Commun (Camb) ; 52(20): 3951-4, 2016 Mar 11.
Artigo em Inglês | MEDLINE | ID: mdl-26879461

RESUMO

Electrochemically-assisted microwave deposition technology, a facile method for the fabrication of luminescent metal-organic framework (LMOF) films, is presented herein. This method was further developed into a versatile method for preparing patterned LMOF films. The strategy based on this method can spatially locate microcrystals of MOFs on a surface, which provides great promise in anti-counterfeiting barcode applications.


Assuntos
Técnicas Eletroquímicas , Elementos da Série dos Lantanídeos/química , Luminescência , Micro-Ondas , Compostos Organometálicos/química , Tamanho da Partícula , Propriedades de Superfície
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