Tunable Photodynamic Switching of DArE@PAF‐1 for Carbon Capture

A new type of photodynamic carbon capture material with up to 26 wt% CO₂ desorption capacity is synthesized via incorporation of diarylethene (DArE) as guest molecules in porous aromatic framework‐1 (PAF‐1). In these host–guest complexes, the carboxylic acid groups featured in DArE allow multiple noncovalent interactions to exist. DArE loadings ranging from 1 to 50 wt% are incorporated in PAF‐1 and the complexes characterized by UV–vis spectroscopy, FT‐IR spectroscopy, CO₂, and N₂ adsorption. Successful inclusion of DArE in PAF‐1 is indicated by the reduction of pore size distributions and an optimum loading of 5 wt% is determined by comparing the percentage photo­response and CO₂ uptake capacity at 1 bar. Mechanistic studies suggest that photoswitching modulates the binding affinity between DArE and CO₂ toward the host, triggering carbon capture and release. This is the first known example of photodynamic carbon capture and release in a PAF.     

Porous Cu(I) Triazolate Framework and Derived Hybrid Membrane with Exceptionally High Sensing Efficiency for Gaseous Oxygen

Phosphorescent complexes of precious metal ions are widely studied as optical sensing materials for molecular oxygen. Combining the advantages of luminescent complexes and porous matrixes, porous coordination polymers show great potential for oxygen‐sensing, although their sensitivity, requirement of precious metal, and device fabrication remain challenging issues. In this work, the photoluminescence and oxygen‐sensing properties of the porous Cu(I) triazolate framework [Cu(detz)] (MAF‐2, Hdetz = 3,5‐diethyl‐1,2,4‐trizole) is studied in detail, which shows high chemical stability in moisture and water, very long phosphorescent lifetime (116 μs) and large Stokes shift (14 562 cm^?1), as well as considerable oxygen permeability (1.7 × 10^?11 mol cm^?1 s^?1 bar^?1) at ambient conditions, giving rise to exceptionally high luminescence quenching efficiency of 99.7% at 1 bar O₂ (I ₀/I ₁₀₀ = 356) with a perfectly linear Stern‐Volmer plot (K _SV = 356 bar^?1, R ² = 0.9998), fast response and good reversibility. Further, a counter‐diffusion crystal‐growth method was developed to fabricate MAF‐2 thin films protected by silicone rubbers as the first example of soft membrane oxygen sensor based on coordination polymer or metal‐organic framework, which exhibited extraordinary oxygen‐sensing performance (limit of detection = 0.047 mbar) and outstanding mechanical property, as well as outstanding chemical stability even in an acidic atmosphere.     

Dye Encapsulated Metal‐Organic Framework for Warm‐White LED with High Color‐Rendering Index

A strategy by encapsulating organic dyes into the pores of a luminescent metal‐organic framework (MOF) is developed to achieve white‐light‐emitting phosphor. Both the red‐light emitting dye 4‐(p‐dimethylaminostyryl)‐1‐methylpyridinium ( DSM ) and the green‐light emitting dye acriflavine ( AF ) are encapsulated into a blue‐emitting anionic MOF ZJU‐28 through an ion‐exchange process to yield the MOF?dye composite ZJU‐28?DSM/AF . The emission color of the obtained composite can be easily modulated by simply adjusting the amount and component of dyes. With careful adjustment of the relative concentration of the dyes DSM and AF , the resulting ZJU‐28?DSM/AF (0.02 wt% DSM , 0.06 wt% AF ) exhibits a broadband white emission with ideal CIE coordinates of (0.34, 0.32), high color‐rendering index value of 91, and moderate correlated color temperature value of 5327 K. Such a strategy can be easily expanded to other luminescent MOFs and dyes, thus opening a new perspective for the development of white light emitting materials.     

Printing of Highly Integrated Crossbar Junctions

A new process is presented that combines nanoimprint lithography and soft lithography to assemble metal–bridge–metal crossbar junctions at ambient conditions. High density top and bottom metal electrodes with half‐pitches down to 50 nm are fabricated in a parallel process by means of ultraviolet nanoimprint lithography. The top electrodes are realized on top of a sacrificial layer and are embedded in a polymer matrix. The lifting of the top electrodes by dissolving the sacrificial layer in an aqueous solution results in printable electrode stamps. Crossbar arrays are noninvasively assembled with high yield by printing the top electrode stamps onto bare or modified bottom electrodes. A semiconducting and a quasi metal like conducting type of polymer are incorporated in the cross points to form metal‐polymer‐metal junctions. The electrical characterization of the printed junctions revealed that the functional integrity of the electrically addressed conductive polymers is conserved during the assembling process. These findings suggest that printing of electrodes represents an easy and cost effective route to highly integrated nanoscale metal‐bridge‐metal junctions if imprint lithography is used for electrode fabrication.     

Functional Defective Metal‐Organic Coordinated Network of Mesostructured Nanoframes for Enhanced Electrocatalysis

Although defects are traditionally perceived as undesired feature, the prevalence of tenacious low‐coordinated defects can instead give rise to desirable functionalities. Here, a spontaneous etching of mesostructured crystal, cyanide‐bridged cobalt‐iron (CN‐CoFe) organometallic hybrid into atomically crafted open framework that is populated with erosion‐tolerant high surface energy defects is presented. Unprecedently, the distinct mechanistic etching pathway dictated by the mesostructured assembly, bulk defects, and strong intercoordinated cyanide‐bridged hybrid mediates not only formation of excess low‐coordinated defects but also more importantly stabilizes them against prevailing dissolution and migration issues. Clearly, the heteropolynuclear cyanide bonded inorganic mesostructured clusters sanction the restructuring of a new breed of stable organometallic polymorph with 3D accessible structure enclosed by electrochemical active atomic stepped edges and high index facets. The exceptional electrocatalysis performance supports the assertion that defective mesostructured polymorph offers a new material paradigm to synthetically tailor the elementary building block constituents toward functional materials.     

Lanthanide Ion Codoped Emitters for Tailoring Emission Trajectory and Temperature Sensing

A series of lanthanide metal‐organic frameworks (Ln‐MOFs) are synthesized through solvothermal conditions with 1,3‐bis(4‐carboxyphenyl)imidazolium (H₂L). Owing to the lanthanide contraction effect, two different types of Ln‐MOFs, namely, {[Ln(L)₂(OH)]·3H₂O}_n (Ln:Pr, Nd, Sm) and {[Ln(L)₂(COO)(H₂O)₂]·H₂O}_n (Ln: Eu, Gd, Tb, Dy, Tm, Yb, Y), and their corresponding codoped Ln‐MOFs Eu_xTb_1‐xL are obtained. With careful adjustment of the relative concentration of the lanthanide ions and the excitation wavelength, the color of the luminescence can be systematically modulated and white light emission can be further successfully achieved. Furthermore, by virtue of the temperature‐dependent luminescent behavior, Eu_0.2Tb_0.8L allows for the design of a thermometer with an excellent linear response to temperature over a wide range, from 40 to 300 K. This work highlights the practical applications of Ln‐MOFs for tailoring fluorescent color and even obtaining practical white light emission, and especially for sensing temperature as luminescent thermometers in a single framework by controlling in different ways.     

Copper Conversion into Cu(OH)2 Nanotubes for Positioning Cu3(BTC)2 MOF Crystals: Controlling the Growth on Flat Plates, 3D Architectures,and as Patterns

A new approach for the fabrication of homogeneous HKUST‐1 [Cu₃(BTC)₂] coatings on copper metal plates, 3D objects, and as patterns, is here proposed. The conversion can be performed at room temperature in approximately 30 minutes using an aqueous ethanolic mixture. The two step conversion mechanism occurs via the formation of Cu(OH)₂ nanotubes. Microscopic time‐course monitoring reveals the conversion steps. The adhesion of the metal organic‐framework (MOF) crystals, as well as the functional properties of the resulting supported catalyst, are successfully tested. The versatility of the conversion mechanism on different metal copper substrates is investigated as well; in particular, a photolithography protocol is proposed for the preparation of MOF patterns. This protocol offers several features (short processing time, applicability to any copper metal object, low cost of the equipment, room temperature conditions) that would make it favorable for basic research and industrial exploitation of MOF capabilities.