Efficient and fast scintillators are in high demand in a variety of fields, such as medical diagnostics, scientific instruments and high-energy physics. However, the trade-off between high scintillation efficiency and fast timing properties is a common challenge facing almost all scintillators. To overcome this limitation, we have developed a strategy for organic scintillators by directing all hot excitons into fast singlet emission states without involving the lowest triplet states. Our scintillator, 1,1,2,2-tetrakis(4-bromophenyl)ethylene, shows an ultrafast radiative lifetime of 1.79 ns and a light yield of ∼34,600 photons per MeV, exhibiting an excellent combination of high light yield and short decay time. Our work provides a method to design efficient and ultrafast scintillators, and paves the way towards exciting applications for ultrafast detection and imaging. Researchers overcome the typical scintillator trade-off between high efficiency and speed. In organic scintillators, researchers drove hot excitons into fast singlet emission states without involving the lowest triplet states, which led to a fast radiative lifetime and strong light yield that may be applicable to ultrafast detection and imaging.

As a promising technology toward high‐efficiency OLED, thermally activated sensitized fluorescence (TASF) has encountered major obstacles toward achieving sufficient operational lifetime when it comes to deep blue emission that is desirable for display applications. We have systematically investigated various factors affecting TASF OLED stability, and successfully improved device lifetime by using a TADF sensitizer with a fast reverse intersystem crossing rate (kRISC).

A serious of phenol and amine bifunctionalized polyacrylonitrile fibers have been prepared and used to catalyze the tandem deprotection-Knoevenagel reaction. Among them, the phenol and tertiary amine bifunctionalized polyacrylonitrile fiber (PANP-TAF) achieved the best catalysis activity. The PANP-TAF was characterized by Fourier-transfer infrared spectroscopy (FTIR), X-ray diffraction spectra (XRD) and elemental analysis (EA). The PANP-TAF can efficiently catalyze Knoevenagel condensation reaction of aromatic aldehydes and methyl cyanoacetateethyl cyanoacetate or malononitrile with high yields of 85

Multiresonance (MR) molecules generally face spectral broadening issues with redshifted emissions. Thus, green emitters with full widths at half maximum (FWHMs) of <20 nm are rarely reported, despite being highly desired. Herein, by properly fusing indolo(3,2,1-jk)carbazole (ICZ) and naphthalene moieties, green MR emitters are reported, which have FWHMs of merely 13 nm (0.064 eV) and 14 nm (0.069 eV) in dichloromethane, accompanied by high photoluminescence quantum yields of >95%, which represent not only the smallest FWHMs among all green MR emitters but also the first green emitters based on ICZ MR derivatives. Theoretical studies reveal that the orbital interactions between the antisymmetric sites of the segments play an important role in extending the conjugation length in the fusion architectures while simultaneously maintaining a small FWHM. The corresponding organic light-emitting diodes exhibit green emission peaks at 508-509 nm and the first green electroluminescence FWHM of <20 nm ever reported. Benefiting from the preferential horizontal dipole orientation, a high maximum external quantum efficiency of up to 30.9% is obtained, which remains at 28.9% and 23.2% under luminances of 1000 and 10 000 cd m-2 , respectively, outperforming most reported green devices based on narrowband emitters.

Polycyclic heteroaromatics with multi-resonance (MR) characteristics are attractive materials for narrowband emitters in wide-color-gamut organic light-emitting diodes. However, MR emitters with pure-red colors are still rare and usually exhibit problematic spectral broadening when redshifting emission. Here, a narrowband pure-red MR emitter is reported by fusing indolocarbazole segments into a boron/oxygen-embedded skeleton, realizing BT.2020 red electroluminescence for the first time together with a high efficiency and an ultralong lifetime. The rigid indolocarbazole segment possesses a strong electron-donating ability due to its para-positioned nitrogen-π-nitrogen backbone and also enlarges the π-extension of the MR skeleton to suppress structural displacement during radiation, achieving concurrently redshifted and narrowed emission spectrum. An emission maximum at 637 nm with a full width at half-maxima of merely 32 nm (0.097 eV) is recorded in toluene. The corresponding device simultaneously exhibits CIE coordinates of (0.708, 0.292) precisely matching the BT.2020 red point, a high external quantum efficiency of 34.4% with low roll-off and an ultralong LT95 (time to 95% of the initial luminance) of >10 000 h at 1000 cd m-2 . These performance characteristics are superior even to those of state-of-the-art perovskite and quantum-dot-based devices for this specific color, paving the way toward practical applications.

Comprehensive Summary Emitters with narrowband spectra are of great importance nowadays because of the growing demand for ultra‐high‐definition displays in the fields of panel displays and solid‐state lighting. Though the reported multiple resonance (MR) emitters have been widely studied with extremely sharp spectra and color‐tunable emissions, the electrophilic borylation synthetic strategies and stable narrowband blue devices still face great challenges. Herein, by virtue of the advantages of both the MR effect of conventional indolocarbazole skeleton and the easy‐to‐access of B—N covalent bonds, the linear tert ‐butyl benzene and carbazole groups modified 6,12‐diphenyl‐5,11‐dihydroindolo[3,2‐ b ]carbazole derivatives (tPh[BN] and Cz[BN]) containing two B—N covalent bonds are easily constructed through amine‐directed double borylation strategy. Both emitters behaved bright blue emission with full‐width‐at‐half‐maximum (FWHM) of 20—27 nm in solution, high fluorescence quantum efficiency over 90%, and excellent stability toward moisture. By employing triplet‐triplet annihilation electroluminescent mechanism, blue OLED devices based on them showed a small FWHM of 48 nm and maximum external quantum efficiency of ~7.1% with negligible efficiency roll‐off, and long operational lifetime (LT80) of 87 h at an initial brightness of 1000 cd·m −2 , demonstrating the enormous application potential of B—N bonds embedded emitters in achieving ideal narrowband blue emitters.

Achieving high exciton utilization is a long-cherished goal in the development of organic light-emitting diode materials. Herein, a three-step mechanism is proposed to achieve 200% exciton utilization: (i) hot triplet exciton (T2) conversion to singlet S1; (ii) singlet fission from S1 into two T1; (iii) and then a Dexter energy transfer to phosphors. The requirement is that S1 should lie slightly lower than or close to T2 and twice as high as T1 in energy. For this, a scenario is put forward to design a series of donor-bridge-acceptor (DBA) type molecules with 2E(T1) ≤ E(S1) < E(T2), in which the Baird-type aromatic pyrazoline ring is used as a bridge owing to its stabilized T1 (1.30-1.74 eV) and different kinds of donors and acceptors are linked to the bridge for regulating S1 (2.35-3.87 eV) and T2 (2.44-3.96 eV). The ultrafast spectroscopy and sensitization measurements for one compound (TPA-DBPrz) fully confirm the theoretical predictions.

Herein, we report a general strategy for achieving ultra-pure green emissions by suppressing the shoulder peaks in the emission spectra of conventional polycyclic aromatic hydrocarbons (PAHs). Through precise synthetic fusion of multi-resonance (MR) fragments with conventional PAH, extended π-conjugation lengths, increased molecular rigidity, and reduced vibrational frequency could be simultaneously realized. The proof-of-concept emitters exhibited ultra-pure green emissions with dominant peaks at ca. 521 nm, photoluminescence quantum yields that are greater than 99 %, a small full-width-at-half-maximum of 23 nm, and CIE coordinates of (0.16, 0.77). The bottom-emitting organic light-emitting diode (OLED) exhibited a record-high CIEy value of 0.74 and a high maximum external quantum efficiency of 30.5 %. The top-emitting OLED not only achieved a BT.2020 green color (CIE: 0.17, 0.78) for the first time but also showed superior performance among all green OLED devices, with a current efficiency of 220 cd A − .

A novel macrocycle of B/N-doped calix[4]arene (C-BN) was synthesized by a one-shot double boronation. Owing to the structural tension and electron-donating properties of the nitrogen atoms in the macrocycle, reaction selectively proceeds between the adjacent benzene rings outside the macrocycle. C-BN shows a highly centrosymmetric structure with two multiple resonance (MR) fragments bridged by tertiary amine groups at the 1,3 positions of the benzene ring. Benefiting from the large intermolecular distance (>4.6 Å) between adjacent MR-emitting cores, C-BN also exhibits excellent narrowband emitting features against aggregation-induced quenching and spectrum broadening. Optimized organic light-emitting diode devices based on C-BN exhibit high maximum external quantum efficiencies of 24.7–26.6 % and small full width at half maximums of 25–28 nm over a wide doping range of 1–12 wt %.

The fabrication of high-efficiency and low-cost adsorbent for the wastewater treatment is a challenging task. In this study, a hollow sphere adsorbent was synthesized from solid waste coal gangue through a facile spray drying method and subsequent calcination. The structure of the synthesized coal gangue microsphere (CM) have been characterized by multimethods including X-ray diffraction, scanning electron microscope, Fourier transform infrared, and others. The factors influencing the adsorption for Cu2+ and Pb2+ by CM were also investigated systemically; pH between 6 and 8 was found to be optimal for Cu2+ and Pb2+ adsorption. The isotherm and kinetic analysis reveal that the adsorption process could be well represented by Langmuir and pseudo-second-order model with a higher R-2 and low chi(2) value. According to Langmuir model, the maximum adsorption capacity was calculated to be 6.570 and 18.904 mg/g for Cu2+ and Pb2+ at 25 degrees C, respectively. The adsorption mechanism was proposed to contain not only the surface reaction process, but also the diffusion process. Consequently, the economic and environmental benefits make CM a promising adsorbent in wastewater treatment.

Engineering mechanically robust ZrO2 foams with three-dimensional (3D) reticular architecture and high porosity is extremely challenging. In current work, we presented an approach for constructing such cellular ceramics via a combined polyurethane foaming and chemical grafting method. Ester functional groups were chemically grafted on the ZrO2 powder surface to enhance its dispersibility. This approach caused the micron-sized windows to assemble onto the cell wall of porous framework, contributing to 3D interconnected reticular architecture. The resulting products with such cellular architecture possessed a high porosity level of 89.2% and maintained an ultrahigh compressive strength of 8.5 MPa. Our results open up new opportunities for fabricating high-performance ZrO2 foams toward practical applications.

White organic light-emitting diodes (WOLEDs) are of great value in daily life. However, the organic white-emissive single molecules in OLEDs are rare. Herein, we report a group of carbazolyl derivatives containing thiophene (PhCz-S), selenophene (PhCz-Se), and tellurophene (PhCz-Te). Through modulating the chalcogen atom, the promoted intersystem crossing brings room-temperature phosphorescence. Moreover, PhCz-Se exhibits Commission Internationale de l'Eclairage (CIE) coordinates of (0.30, 0.29) in OLEDs measured at 4 V, which is the first example of the single-molecule WOLEDs combined with dual emission from singlet and triplet states. Also, PhCz-Te realized WOLEDs in a single emission layer at CIE coordinates of (0.34, 0.33). The theoretical and experimental results clearly show that the adjustment of heavy atoms exerts influence on the luminescent properties, which provides a new strategy for designing single-molecule WOLEDs.

Engineering high performance cellular ceramics with both ultralow density and satisfactory compressive strength for practical applications still represents a grand challenge. Herein, alumina-based cellular ceramics bonded by in-situ formed mullite phase were constructed by Al2O3-Si-boehmite particle-stabilized foams. The gelation of boehmite sol improved the stability and harnessed the deformation of dried Al2O3-Si composite foam. The oxidation of silicon and further generation of in-situ mullite phase enhanced the chemical bond between alumina particles on cell walls, resulting in the superior mechanical properties. As an exemplar, the resulting cellular ceramic possessed the robust compressive strength of 2.26 MPa at a high porosity of 87.8%. The gelation-assisted Al2O3-Si particle-stabilized foams provide a facile and convenient strategy for construction of composite ceramic foams with high porosity and robust strength.

The design and synthesis of new filtration materials for high-temperature particulate matter capture are of both technological and scientific importance but still remain a challenging task. In the current work, we presented an approach for the manufacturing of highly porous SiC cellular ceramics by combining polyether polyol-modified carbon black with polyurethane foaming method. Hydroxyl groups were introduced to the surface of carbon black to prevent agglomeration. As-obtained SiC cellular ceramic possed three-dimensional interconnected reticular architecture with the abundant micron-sized window on its cell wall. The resulting porous SiC ceramic exhibited a high removal efficiency (95.8%) with extremely low pressure drop (38 Pa). The successful fabrication of such fascinating material may provide new insights for high-temperature particulate matter filtration.

Engineering highly porous SiC foams with interconnected cellular architecture and satisfactory compressive strength for the practical applications remains a challenging task. In the current work, SiC foams bonded by insitu formed mullite phase were fabricated via polyurethane foaming using boehmite sol-coated SiC powder as the raw material. The strategy in the current work endowed the resultant products with ultrahigh porosity, interconnected pore structure, and a robust mullite bonding phase among the SiC particles. The resulting products with this cellular architecture possessed a high porosity level of 88.5% and maintained a robust compressive strength of 2.56 MPa. Our results showed that as-prepared products are promising for practical applications in the filtration, adsorption and catalytic areas.

Nanofibrous aerogels constructed solely by ceramic components with temperature-invariant hyper-elasticity could have broad technological implications in extreme environments. However, creating such materials has proven to be extremely challenging. Despite the results from laboratory, those aerogels are, unfortunately, still plagued with issues that would retard their further application: inferior structural integrity, failure at large compressive deformation, high production cost, and inability to withstand rigorous working conditions. To tackle these challenges, we report a facile strategy combining the chemical vapor deposition process and layer-by-layer self-assembly to construct hyperelastic SiC nanofibrous aerogels with three-dimensional porous architecture and improved structural integrity. The resultant aerogels outperform their natural counterparts and most state-of-the-art ceramic nanofibrous aerogels in their capability to quickly recover from large compressive deformation (50% strain), function in a wide range of temperatures, from -196 degrees C to 1100 degrees C in air, maintain high particle matter removal efficiency of >99.96%, and rapidly absorb various organic solvents and oils with high capacity and robust recoverability. Nanofibrous aerogels constructed by such a versatile method could provide fresh insights into the exploration of multifunctional nanofibrous aerogels for a variety of applications in extreme environments.

Developing new filters for the effective removal of high-temperature particulate matter is of great importance but still remains a challenge. Herein, we demonstrate a novel and facile strategy for producing hierarchical ceramic foams with three-dimensional interconnected porous architecture via the combination of chemical grafting of pore-forming agent and polyurethane foaming technique. Carbamate groups are directly grafted onto carbon black surface to enhance its dispersion. Abundant micrometer-sized pores are generated on the cell walls of porous frameworks to form three-dimensional interconnected porous architectures, resulting in the mullite foam with high particulate matter removal efficiency and relatively low pressure drop. The optimized mullite foam exhibits integrated properties of high particulate matter removal efficiency (96.7%), ultralow pressure drop (35 Pa), and outstanding recyclability. Our results open new opportunities for fabricating efficient particulate matter filters used in high-temperature environmental fields.

A degradable ROS responsive selenide-containing block polymer would undergo an oxidation-related elimination and degradation process.

A facile method for preparation of SiC nanofibrous network reinforced hierarchical structured porous Si3N4 based ceramics via annealing Si-Si3N4 binary particle-stabilized foam in coke bed is reported in this work for the first time. The atmosphere created by coke bed enables the fabrication of Si3N4 based porous ceramics at 1450 degrees C without using sintering additives. As prepared specimens possess a relative high compressive strength due to the partial oxidation of Si3N4 particles. This novel structure with three levels of hierarchy characterized by flexible SiC nanofibrous network, cell walls and unit cells can be characterized. The vaporization of silicon powder results in formation of Si(g), SiO(g) and allows subsequent generation of SiC nanofibrous network, leading to a considerable number of micro-pores on cell walls simultaneously. As-prepared porous ceramics contained 76.7% porosity and had compressive strength of 10.81 MPa.

Porous ceramics with high porosity and extensive interconnected pores have great application potential in fields ranging from dye removal to high-temperature particulate matter (PM) capture. However, constructing these materials to achieve efficient filtration is extremely challenging. Herein, a novel strategy to create hierarchical-structured porous alumina ceramics (PACs) with three-dimensional (3D) reticular architecture is reported based on polyurethane (PU) foaming method. To ensure the efficient flow-through filtration, carbamate-grafted carbon black is used as the pore-forming agent and assembled into the porous PU framework. Submicron and micron-sized pores on the cell walls are observed in hierarchical-structured PACs. This unique structure enables a high PM removal efficiency (94.1%) at an ultralow pressure drop (20 Pa). Our work has demonstrated great application potentials of as-prepared PACs as an efficient high-temperature PM filter and provided new insights to develop highly effective filter.