Abstract
Designing organic fluorescent and phosphorescent materials based on various core fluorophore has gained great attention, but it is unclear whether similar luminescent units exist for ...inorganic materials. Inspired by the BX
6
octahedral structure of luminescent metal halide perovskites (MHP), here we propose that the BX
6
octahedron may be a core structure for luminescent inorganic materials. In this regard, excitation-dependent color-tunable phosphorescence is discovered from α-AlF
3
featuring AlF
6
octahedron. Through further exploration of the BX
6
unit by altering the dimension and changing the center metal (B) and ligand (X), luminescence from KAlF
4
, (NH
4
)
3
AlF
6
, AlCl
3
, Al(OH)
3
, Ga
2
O
3
, InCl
3
, and CdCl
2
are also discovered. The phosphorescence of α-AlF
3
can be ascribed to clusterization-triggered emission, i.e., weak through space interaction of the
n
electrons of F atoms bring close proximity in the AlF
6
octahedra (inter/intra). These discoveries will deepen the understanding and contribute to further development of BX
6
octahedron-based luminescent materials.
The unusual room‐temperature phosphorescence (RTP) from the n electron‐rich systems (without regular conjugated structure) has aroused great attention for structural designing and application ...development of RTP materials. Such emission has been ascribed to clusterization‐triggered emission (CTE) via weak through‐space conjugation of n electrons in the heteroatoms. However, there was suspicion on such RTP as impurity‐induced result. Therefore, in‐depth photophysical investigation and effective proof methods are needed to trace the origin of such RTP. Here, using the recently reported CTE phosphor boric acid as the example, a Jablonski diagram‐based verification protocol was proposed to confirm the intrinsic luminescence of the n electrons‐rich systems. Meanwhile, some other types of luminophores, that is, traditional phosphors, already reported impurity‐induced and host‐guest doping luminophores, were included for comparison. Overall, this work provides a basic paradigm for differentiating between the impurity‐involved and the n electron‐rich phosphors and will further deepen the understanding of nonconventional luminescence.
Unusual phosphorescence was identified from boric acid, but was questioned as impurity‐induced result. Here, we proposed a protocol to verify the origin of such phosphorescence, namely from weak through‐space conjugation rather than impurity.
Solid-state nanopore in analytical chemistry has developed rapidly in the 1990s and it is proved to be a versatile new tool for bioanalytical chemistry. This review focuses on the analysis of ions ...and small molecules with nanopores including nanopipettes, polymer film nanopores, Si3N4 nanopores, graphene nanopores, MoS2 nanopores and MOFs.
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Solid-state nanopore in analytical chemistry has developed rapidly in the 1990s and it is proved to be a versatile new tool for bioanalytical chemistry. The research field of solid-state nanopore starts from mimicking the biological nanopore in living cells. Understanding the transport mechanism of biological nanopore in vivo is a big challenge because of the experimental difficulty, so it is essential to establish the basic research of artificial nanopores in vitro especially for the analysis of ions and small molecules. The performance of solid-state nanopores could be evaluated by monitoring currents when ions and molecules passed through. The comparison of the two types of nanopores based on current-derived information can reveal the principle of biological nanopores, while the solid-state nanopores are applied into practical bioanalysis. In this review, we focus on the researches of the solid-state nanopores in the fabrication process and in the analysis of ions and small molecules. Fabrication methods of nanopores, ion transport mechanism, small molecule analysis and theoretical studies are discussed in detail.
For a long time, phosphors with long‐lived emission are dominated by rare earth/transition metal ion‐doped sulfides and oxides. Recently, organic materials capable of emitting long‐lived ...room‐temperature phosphorescence (RTP) are reported, carbon skeletons are almost the exclusive structural feature of the conjugated luminophores. Herein, we reported that boric acid, a non‐metal and C‐free material, could emit RTP with lifetime up to 0.3 s. Detailed investigations indicated the weak conjugation between the n electrons of the O atoms in the B‐O confined space was the possible origin of RTP. Similar RTP was also found in electron‐rich N/F systems, namely, BN and BF3 (BF4−). Importantly, the vacant pz0
orbital of B was found to contribute to the relevant unoccupied molecular orbitals involved in excitation, which is different from previous reports on phosphorescence from arylboronic acids. The results confirm the unique role of B as a versatile structure motif for construction of new RTP materials.
The vacant pz0
orbital of boron contributes to the unexpected long‐lived room‐temperature phosphorescence of boric acid, boron nitride, and fluoborite.
Supported noble metal nanoparticles (NMNPs) are appealing for energy and environment catalysis. To facilitate the loading of NMNPs, in situ reduction of Mn+ on the support with extra ...reductants/surfactants is adopted, but typically results in aggregated NMNPs with uneven size distributions or blocked active sites of the NMNPs. Herein, the use of cobalt layered double hydroxide (Co‐LDH) is proposed as both support and reductant for the preparation of supported NMNPs with ultrasmall sizes and even distributions. The resultant Co‐LDH‐supported NMNPs exhibit excellent catalytic performance and stability. For example, Ir/Co‐LDH displays a low overpotential of 188 mV (10 mA cm−2) for electrocatalytic oxygen evolution reaction and a long‐term stability over 100 h (100 mA cm−2) in overall water splitting. Ru/Co‐LDH can achieve a 4‐nitrophenol reduction with high rate of 0.36 min−1 and S2− detection with low limit of detection (LOD) of 0.34 µm. Overall, this work provides a green and effective strategy to fabricate supported NMNPs with greatly improved catalytic performances.
A simple and environment‐friendly spontaneous reduction strategy is proposed for the preparation of supported noble metal nanoparticles (NMNPs) with ultrasmall sizes (M = Ru, Pd, Pt, Au, Ag, Ir) and even size distributions. The developed Co‐LDH‐supported ultrasmall NMNPs are explored for advanced energy and environment catalysis.
Comprehensive Summary
Room‐temperature phosphorescence (RTP) has gained much attention in organic light‐emitting diodes (OLEDs), anti‐counterfeiting, encryption and bioimaging. However, efficient RTP ...is typically difficult due to the spin‐forbidden transition nature and susceptibility to environment quenching. In aqueous phase, such quenching is much more pronounced, leading to the collection of aqueous RTP even more challenging. Assembly systems (either organic or inorganic), provide an excellent microenvironment for accommodating of phosphors in aqueous phase, due to the excluding of typical phosphorescence quenchers (H2O and O2) and rigidification of phosphorescent molecules for inhibition of non‐radiative transitions (molecular motions). Herein, we summarized the recent progress in harvesting RTP from aqueous systems via various assembling strategies, including small molecules, supramolecular inclusion, and inorganic assembly. More specifically, the analytical explorations of these systems were discussed, from the perspective of the relationship between analytes and phosphorescence. Last, the further developments of aqueous RTP analysis were also prospected.
In this review, the recent progress in harvesting RTP from aqueous systems via various assembling strategies is summarized and the analytical explorations of these systems were discussed. In addition, the further developments of aqueous RTP analysis were also prospected.
The impressive and unexpected long‐lived room‐temperature phosphorescence of boric acid (H3BO3) is unveiled by Peng Wu and co‐workers in their Research Article on page 9500. Unlike traditional ...metallic inorganic or aromatic organic phosphors, the phosphorescence originates from the weak conjugation of lone pair electrons from O atoms. The vacant pz orbital of B and the regular arrangement in the crystalline state with layer‐like packing through abundant hydrogen bonding are found to contribute to the long‐lived emission.
Die erstaunliche und unerwartete langlebige Raumtemperatur‐Phosphoreszenz von Borsäure (H3BO3) wurde von Peng Wu et al. im Forschungsartikel auf S. 9586 aufgedeckt. Im Gegensatz zu herkömmlichen ...metallischen anorganischen oder aromatischen organischen Phosphoren stammt die Phosphoreszenz aus der schwachen Konjugation einsamer Elektronenpaare der O‐Atome. Das vakante pz‐Orbital von B und die regelmäßige Anordnung im kristallinen Zustand mit schichtartiger Packung durch Wasserstoffbrückenbindungen tragen zu der langlebigen Emission bei.
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