Metal–organic frameworks (MOFs) display a wide range of luminescent behaviors resulting from the multifaceted nature of their structure. In this critical review we discuss the origins of MOF luminosity, which include the linker, the coordinated metal ions, antenna effects, excimer and exciplex formation, and guest molecules. The literature describing these effects is comprehensively surveyed, including a categorization of each report according to the type of luminescence observed. Finally, we discuss potential applications of luminescent MOFs. This review will be of interest to researchers and synthetic chemists attempting to design luminescent MOFs, and those engaged in the extension of MOFs to applications such as chemical, biological, and radiation detection, medical imaging, and electro-optical devices (141 references).

Luminescent Metal–Organic Frameworks

Lanthanide-based luminescent hybrid materials.

Interpretation of europium(III) spectra

Cerium dioxide (CeO2, ceria) is becoming an ubiquitous constituent in catalytic systems for a variety of applications. 2016 sees the 40th anniversary since ceria was first employed by Ford Motor Company as an oxygen storage component in car converters, to become in the years since its inception an irreplaceable component in three-way catalysts (TWCs). Apart from this well-established use, ceria is looming as a catalyst component for a wide range of catalytic applications. For some of these, such as fuel cells, CeO2-based materials have almost reached the market stage, while for some other catalytic reactions, such as reforming processes, photocatalysis, water-gas shift reaction, thermochemical water splitting, and organic reactions, ceria is emerging as a unique material, holding great promise for future market breakthroughs. While much knowledge about the fundamental characteristics of CeO2-based materials has already been acquired, new characterization techniques and powerful theoretical methods are dee...

Fundamentals and Catalytic Applications of CeO2-Based Materials

Advanced oxidation processes (AOPs), defined as those technologies that utilize the hydroxyl radical (·OH) for oxidation, have received increasing attention in the research and development of wastewater treatment technologies in the last decades. These processes have been applied successfully for the removal or degradation of toxic pollutants or used as pretreatment to convert recalcitrant pollutants into biodegradable compounds that can then be treated by conventional biological methods. The efficacy of AOPs depends on the generation of reactive free radicals, the most important of which is the hydroxyl radical (·OH). The authors summarize the formation reactions of ·OH and the mechanisms of pollutants degradation. They cover six types of advanced oxidation processes, including radiation, photolysis and photocatalysis, sonolysis, electrochemical oxidation technologies, Fenton-based reactions, and ozone-based processes. Controversial issues in pollutants degradation mechanism were discussed. They review t...

Advanced Oxidation Processes for Wastewater Treatment: Formation of Hydroxyl Radical and Application

This critical review mainly focuses on recent research progress in photofunctional lanthanide hybrid materials The review covers hybrids with complexes of organically modified silanes as precursors for sol–gel processing, hybrids with lanthanide complex units grafted onto the interior of mesoporous hosts, hybrids with lanthanide complex units on polymer chains, and other non-silica or composite-based lanthanide hybrids The photophysical properties of lanthanide hybrids are also discussed Finally, future challenges and opportunities in this field are discussed

Recent progress in photofunctional lanthanide hybrid materials

A 3D microporous compound Al(OH) (H2btec)·H2O (MIL-121) containing uncoordinated carbonyl groups is selected as a parent metal–organic framework (MOF). Moreover, because the uncoordinated carbonyl groups in the channels could act as a postsynthetic modification sites, a robust luminescent lanthanide-based MOF can be constructed by encapsulating Eu3+ cations into the pores of MIL-121. The intense luminescence of Eu3+ incorporated MIL-121 products demonstrates that the framework with rigid, permanently porous structure and non-coordinated carboxyl group is an efficient scaffold for hosting and sensitizing Eu3+ cations. More significantly, the robust Eu3+@MIL-121 shows excellent selectivity, fast detection time (<5 min), and high sensitivity (detection limit, 0.1 μM) for Ag+ ions in aqueous solution due to a great enhancement of the Eu3+-luminescence. This is a rare example of Ag+ detection in aqueous solutions based on a luminescent lanthanide MOFs.

Highly sensitive and selective fluorescent probe for Ag+ based on a Eu3+ post-functionalized metal–organic framework in aqueous media

BiVO4/Bi2O3 submicrometer sphere composite: Microstructure and photocatalytic activity under visible-light irradiation

CeO 2 –Bi 2 O 3 composite was synthesized via a two-stage process. The precursors were prepared from Ce(NO 3 ) 3 ·6H 2 O, Bi(NO 3 ) 3 ·5H 2 O and CO(NH 2 ) 2 with different molar ratio through the hydrothermal process, and then was completed by carrying out the precursors for 4 h at 600 °C under flowing air atmosphere. Techniques of X-ray diffraction (XRD), transmission electron microscopic (TEM) and diffuse reflectance ultraviolet–vis spectra (UV-DRS) were employed to characterize the as-synthesized materials. The results showed that the microstructure and morphology of CeO 2 –Bi 2 O 3 composite were similar in spite of different inverse proportion. We also investigated improved photocatalytic activity in the case of CeO 2 –Bi 2 O 3 composite catalyst compared to the catalytic activity of pure Bi 2 O 3 or CeO 2 powder. The suppression of charge recombination in the composite CeO 2 –Bi 2 O 3 catalyst led to higher catalytic activity for the degradation of RhB. The CeO 2 10%/Bi 2 O 3 photocatalyst exhibited maximum photocatalytic activity. The photocatalytic activity is in close relation with the inverse proportion between reactants.

CeO2–Bi2O3 nanocomposite: Two step synthesis, microstructure and photocatalytic activity

Eu(III)-functionalized In-MOF (In(OH)bpydc) as fluorescent probe for highly selectively sensing organic small molecules and anions especially for CHCl3 and MnO4−

Bing Yan

Papers

Recent progress in photofunctional lanthanide hybrid materials

Highly sensitive and selective fluorescent probe for Ag+ based on a Eu3+ post-functionalized metal–organic framework in aqueous media

BiVO4/Bi2O3 submicrometer sphere composite: Microstructure and photocatalytic activity under visible-light irradiation

CeO2–Bi2O3 nanocomposite: Two step synthesis, microstructure and photocatalytic activity

Eu(III)-functionalized In-MOF (In(OH)bpydc) as fluorescent probe for highly selectively sensing organic small molecules and anions especially for CHCl3 and MnO4−