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Showing papers by "Nanjing Tech University published in 2018"


Journal ArticleDOI
27 Aug 2018-Nature
TL;DR: All-inorganic perovskite nanocrystals containing caesium and lead provide low-cost, flexible and solution-processable scintillators that are highly sensitive to X-ray irradiation and emit radioluminescence that is colour-tunable across the visible spectrum.
Abstract: The rising demand for radiation detection materials in many applications has led to extensive research on scintillators1–3. The ability of a scintillator to absorb high-energy (kiloelectronvolt-scale) X-ray photons and convert the absorbed energy into low-energy visible photons is critical for applications in radiation exposure monitoring, security inspection, X-ray astronomy and medical radiography4,5. However, conventional scintillators are generally synthesized by crystallization at a high temperature and their radioluminescence is difficult to tune across the visible spectrum. Here we describe experimental investigations of a series of all-inorganic perovskite nanocrystals comprising caesium and lead atoms and their response to X-ray irradiation. These nanocrystal scintillators exhibit strong X-ray absorption and intense radioluminescence at visible wavelengths. Unlike bulk inorganic scintillators, these perovskite nanomaterials are solution-processable at a relatively low temperature and can generate X-ray-induced emissions that are easily tunable across the visible spectrum by tailoring the anionic component of colloidal precursors during their synthesis. These features allow the fabrication of flexible and highly sensitive X-ray detectors with a detection limit of 13 nanograys per second, which is about 400 times lower than typical medical imaging doses. We show that these colour-tunable perovskite nanocrystal scintillators can provide a convenient visualization tool for X-ray radiography, as the associated image can be directly recorded by standard digital cameras. We also demonstrate their direct integration with commercial flat-panel imagers and their utility in examining electronic circuit boards under low-dose X-ray illumination. All-inorganic perovskite nanocrystals containing caesium and lead provide low-cost, flexible and solution-processable scintillators that are highly sensitive to X-ray irradiation and emit radioluminescence that is colour-tunable across the visible spectrum.

1,064 citations


Journal ArticleDOI
TL;DR: It is shown that micrometre-sized metallic 1T′-MoS2- and 1T-MoSe2-layered crystals can be prepared in high phase purity on a large scale, and that they display promising electrocatalytic activity towards the hydrogen evolution reaction.
Abstract: Phase control plays an important role in the precise synthesis of inorganic materials, as the phase structure has a profound influence on properties such as conductivity and chemical stability. Phase-controlled preparation has been challenging for the metallic-phase group-VI transition metal dichalcogenides (the transition metals are Mo and W, and the chalcogens are S, Se and Te), which show better performance in electrocatalysis than their semiconducting counterparts. Here, we report the large-scale preparation of micrometre-sized metallic-phase 1T′-MoX2 (X = S, Se)-layered bulk crystals in high purity. We reveal that 1T′-MoS2 crystals feature a distorted octahedral coordination structure and are convertible to 2H-MoS2 following thermal annealing or laser irradiation. Electrochemical measurements show that the basal plane of 1T′-MoS2 is much more active than that of 2H-MoS2 for the electrocatalytic hydrogen evolution reaction in an acidic medium.

657 citations


Journal ArticleDOI
TL;DR: In this article, the authors present state-of-the-art research on nonradical pathways in persulfate-based AOPs, with emphases on the controversial methodologies for identifying the oxygen reactive species (ROS), ambiguous reaction mechanisms, intrinsic impacts of metal/carbon catalysts and organic substrates in the nonradical-based catalytic oxidation reactions.
Abstract: Recent discoveries of nonradical oxidation in aqueous-phase advanced oxidation processes (AOPs) have induced tremendous interest in environmental remediation of wastewater, whereas different findings from a variety of investigations have also raised severe controversies in the occurrence and mechanism of the nonradical reaction. Hence, critical understandings of the nonradical reaction will significantly advance the knowledge and its application for catalytic oxidation and wastewater treatment. In this review, we would like to present state-of-the-art research on nonradical pathways in persulfate-based AOPs, with emphases on the controversial methodologies for identifying the oxygen reactive species (ROS), ambiguous reaction mechanisms, intrinsic impacts of metal/carbon catalysts and organic substrates in the nonradical-based catalytic oxidation reactions. Moreover, further research directions on mechanistic investigation of the nonradical pathway with rational experimental design and advanced strategies, as well as the potential applications of the nonradical system are proposed.

619 citations


Journal ArticleDOI
23 Jan 2018-ACS Nano
TL;DR: The versatile and scalable Ti3C2Tx MXene/CNT strain sensors provide a promising route to future wearable artificial intelligence with comprehensive tracking ability of real-time and in situ physiological signals for health and sporting applications.
Abstract: It remains challenging to fabricate strain-sensing materials and exquisite geometric constructions for integrating extraordinary sensitivity, low strain detectability, high stretchability, tunable sensing range, and thin device dimensions into a single type of strain sensor. A percolation network based on Ti3C2Tx MXene/carbon nanotube (CNT) composites was rationally designed and fabricated into versatile strain sensors. This weaving architecture with excellent electric properties combined the sensitive two-dimensional (2D) Ti3C2Tx MXene nanostacks with conductive and stretchable one-dimensional (1D) CNT crossing. The resulting strain sensor can be used to detect both tiny and large deformations with an ultralow detection limit of 0.1% strain, high stretchability (up to 130%), high sensitivity (gauge factor up to 772.6), tunable sensing range (30% to 130% strain), thin device dimensions ( 5000 cycles). The versatile and scalable Ti3C2Tx MXene/CNT strain sens...

605 citations


Journal ArticleDOI
TL;DR: In this paper, the relationship among structures, materials, properties and applications of auxetic metamaterials and structures is discussed. And the challenges and future work on the topic of auxetics are also presented to inspire prospective research work.
Abstract: Materials and structures with negative Poisson's ratio exhibit a counter-intuitive behaviour. Under uniaxial compression (tension), these materials and structures contract (expand) transversely. The materials and structures that possess this feature are also termed as 'auxetics'. Many desirable properties resulting from this uncommon behaviour are reported. These superior properties offer auxetics broad potential applications in the fields of smart filters, sensors, medical devices and protective equipment. However, there are still challenging problems which impede a wider application of auxetic materials. This review paper mainly focuses on the relationships among structures, materials, properties and applications of auxetic metamaterials and structures. The previous works of auxetics are extensively reviewed, including different auxetic cellular models, naturally observed auxetic behaviour, different desirable properties of auxetics, and potential applications. In particular, metallic auxetic materials and a methodology for generating 3D metallic auxetic materials are reviewed in details. Although most of the literature mentions that auxetic materials possess superior properties, very few types of auxetic materials have been fabricated and implemented for practical applications. Here, the challenges and future work on the topic of auxetics are also presented to inspire prospective research work. This review article covers the most recent progress of auxetic metamaterials and auxetic structures. More importantly, several drawbacks of auxetics are also presented to caution researchers in the future study.

603 citations


Journal ArticleDOI
TL;DR: In this article, the most recent developments on high-performance anode materials for SIBs are summarized, and different reaction mechanisms, challenges associated with these materials, and effective approaches to enhance performance are discussed.
Abstract: Due to massively growing demand arising from energy storage systems, sodium ion batteries (SIBs) have been recognized as the most attractive alternative to the current commercialized lithium ion batteries (LIBs) owing to the wide availability and accessibility of sodium. Unfortunately, the low energy density, inferior power density and poor cycle life are still the main issues for SIBs in the current drive to push the entire technology forward to meet the benchmark requirements for commercialization. Over the past few years, tremendous efforts have been devoted to improving the performance of SIBs, in terms of higher energy density and longer cycling lifespans, by optimizing the electrode structure or the electrolyte composition. In particular, among the established anode systems, those materials, such as metals/alloys, phosphorus/phosphides, and metal oxides/sulfides/selenides, that typically deliver high theoretical sodium-storage capacities have received growing interest and achieved significant progress. Although some review articles on electrodes for SIBs have been published already, many new reports on these anode materials are constantly emerging, with more promising electrochemical performance achieved via novel structural design, surface modification, electrochemical performance testing techniques, etc. So, we herein summarize the most recent developments on these high-performance anode materials for SIBs in this review. Furthermore, the different reaction mechanisms, the challenges associated with these materials, and effective approaches to enhance performance are discussed. The prospects for future high-energy anodes in SIBs are also discussed.

536 citations


Journal ArticleDOI
TL;DR: In this article, the authors demonstrate perovskite-polymer bulk heterostructure light-emitting diodes exhibiting external quantum efficiencies of up to 20.1% (at current densities of 0.1-1.1 µm−2).
Abstract: Perovskite-based optoelectronic devices are gaining much attention owing to their remarkable performance and low processing cost, particularly for solar cells. However, for perovskite light-emitting diodes, non-radiative charge recombination has limited the electroluminescence efficiency. Here we demonstrate perovskite–polymer bulk heterostructure light-emitting diodes exhibiting external quantum efficiencies of up to 20.1% (at current densities of 0.1–1 mA cm−2). The light-emitting diode emissive layer comprises quasi-two-dimensional and three-dimensional (2D/3D) perovskites and an insulating polymer. Photogenerated excitations migrate from quasi-2D to lower-energy sites within 1 ps, followed by radiative bimolecular recombination in the 3D regions. From near-unity external photoluminescence quantum efficiencies and transient kinetics of the emissive layer with and without charge-transport contacts, we find non-radiative recombination pathways to be effectively eliminated, consistent with optical models giving near 100% internal quantum efficiencies. Although the device brightness and stability (T50 = 46 h in air at peak external quantum efficiency) require further improvement, our results indicate the significant potential of perovskite-based photon sources.

449 citations


Journal ArticleDOI
TL;DR: Experimental observations of robust intralayer ferroelectricity in two-dimensional van der Waals layered α-In2Se3 ultrathin flakes at room temperature are reported.
Abstract: Enriching the functionality of ferroelectric materials with visible-light sensitivity and multiaxial switching capability would open up new opportunities for their applications in advanced information storage with diverse signal manipulation functions. We report experimental observations of robust intralayer ferroelectricity in two-dimensional (2D) van der Waals layered α-In2Se3 ultrathin flakes at room temperature. Distinct from other 2D and conventional ferroelectrics, In2Se3 exhibits intrinsically intercorrelated out-of-plane and in-plane polarization, where the reversal of the out-of-plane polarization by a vertical electric field also induces the rotation of the in-plane polarization. On the basis of the in-plane switchable diode effect and the narrow bandgap (∼1.3 eV) of ferroelectric In2Se3, a prototypical nonvolatile memory device, which can be manipulated both by electric field and visible light illumination, is demonstrated for advancing data storage technologies.

439 citations


Journal ArticleDOI
TL;DR: In this article, a comparative study of BSCF and Co3O4 nanocrystals was performed, including electrochemical impedance spectroscopy (EIS) and cyclic voltammograms (CV) in PMS solution as well as hydrogen temperatureprogrammed reduction (H2-TPR) and oxygen temperature-programmed desorption (O 2-TPD) tests.
Abstract: Metal-based catalysis has significantly contributed to the chemical community especially in environmental science. However, the knowledge of cobalt-based perovskite for aqueous phase oxidation still remains equivocal and insufficient. In this study, we discovered that Ba0.5Sr0.5Co0.8Fe0.2O3-δ (BSCF) perovskite was exclusively effective for peroxymonosulfate (PMS) activation to produce free radicals, whereas the BSCF was inert to activate peroxydisulfate (PDS) and hydrogen peroxide. The BSCF/PMS exhibited superior performance to the benchmark Co3O4 nanocrystals and other classical PMS activators such as α-MnO2 and spinel CoFe2O4, meanwhile achieving an impressive stability with manipulated cobalt leaching in neutral and basic environment. In situ electron paramagnetic resonance (EPR) revealed the evolution of massive sulfate radicals (SO4 −) and hydroxyl radicals ( OH) during the oxidation. A comprehensively comparative study of BSCF and Co3O4 nanocrystals was performed, including electrochemical impedance spectroscopy (EIS) and cyclic voltammograms (CV) in PMS solution as well as hydrogen temperature-programmed reduction (H2-TPR) and oxygen temperature-programmed desorption (O2-TPD) tests. The results unveil that the cobalt-based perovskite, BSCF, exhibited a better electrical conductivity and redox potential than the spinel cobalt oxide to interact with PMS. More importantly, the oxygen vacancies and less-electronegativity A-site metals may secure cobalt sites with a lower valence state for donating electrons to PMS simultaneously for radical generation. This study advances the mechanism of cobalt-based heterogeneous catalysis in environmental remediation.

409 citations


Journal ArticleDOI
TL;DR: Efficient incorporation of engineered submicrometre-sized metal–organic framework (MOF) crystals into polymers to form hybrid materials that successfully translate the excellent molecular sieving properties of face-centred cubic (fcu)-MOFs into the resultant membranes are reported on.
Abstract: Membrane-based separations can improve energy efficiency and reduce the environmental impacts associated with traditional approaches. Nevertheless, many challenges must be overcome to design membranes that can replace conventional gas separation processes. Here, we report on the incorporation of engineered submicrometre-sized metal–organic framework (MOF) crystals into polymers to form hybrid materials that successfully translate the excellent molecular sieving properties of face-centred cubic (fcu)-MOFs into the resultant membranes. We demonstrate, simultaneously, exceptionally enhanced separation performance in hybrid membranes for two challenging and economically important applications: the removal of CO2 and H2S from natural gas and the separation of butane isomers. Notably, the membrane molecular sieving properties demonstrate that the deliberately regulated and contracted MOF pore-aperture size can discriminate between molecular pairs. The improved performance results from precise control of the linkers delimiting the triangular window, which is the sole entrance to the fcu-MOF pore. This rational-design hybrid approach provides a general toolbox for enhancing the transport properties of advanced membranes bearing molecular sieve fillers with sub-nanometre-sized pore-apertures. Sub-micrometre MOF particles are incorporated into polymers to form mixed matrix membranes. Molecular sieving enables performance far beyond current limits for two applications, butane isomer separation and combined CO2/H2S removal from natural gas.

395 citations


Journal ArticleDOI
TL;DR: In this paper, a binary networked conductive hydrogel is prepared using acrylamide and polyvinyl alcohol, and an ultrastretchable pressure sensor with biocompatibility and transparency is fabricated cost effectively.
Abstract: In this study, a binary networked conductive hydrogel is prepared using acrylamide and polyvinyl alcohol. Based on the obtained hydrogel, an ultrastretchable pressure sensor with biocompatibility and transparency is fabricated cost effectively. The hydrogel exhibits impressive stretchability (>500%) and superior transparency (>90%). Furthermore, the self-patterned microarchitecture on the hydrogel surface is beneficial to achieve high sensitivity (0.05 kPa−1 for 0–3.27 kPa). The hydrogel-based pressure sensor can precisely monitor dynamic pressures (3.33, 5.02, and 6.67 kPa) with frequencydependent behavior. It also shows fast response (150 ms), durable stability (500 dynamic cycles), and negligible current variation (6%). Moreover, the sensor can instantly detect both tiny (phonation, airflowing, and saliva swallowing) and robust (finger and limb motions) physiological activities. This work presents insights into preparing multifunctional hydrogels for mechanosensory electronics.

Journal ArticleDOI
TL;DR: This work outlines for the first time all necessary considerations for the appropriate use of PAINS filters.
Abstract: Pan-Assay Interference Compounds (PAINS) are very familiar to medicinal chemists who have spent time fruitlessly trying to optimize these nonprogressible compounds. Electronic filters formulated to recognize PAINS can process hundreds and thousands of compounds in seconds and are in widespread current use to identify PAINS in order to exclude them from further analysis. However, this practice is fraught with danger because such black box treatment is simplistic. Here, we outline for the first time all necessary considerations for the appropriate use of PAINS filters.

Journal ArticleDOI
TL;DR: In this article, a non-noble-metal NRR electrocatalyst for N2 conversion to NH3 with high activity and selectivity was proposed, and the catalytic mechanism of NRR on Nb2O5 surface was further discussed by density functional theory calculations.


Journal ArticleDOI
TL;DR: In this review, published experimental and theoretical results for IL/DES-H2O systems at varied water concentrations are collected and analyzed and a new conceptual framework is suggested for thermodynamic modelling of IL/ DES- H2O binary systems to enable new technologies for their practical applications.
Abstract: Ionic liquids (ILs) and deep eutectic solvents (DESs) have been suggested as eco-friendly alternatives to organic solvents. A trace amount of water is often unavoidable as impurity, and water is also added on purpose to reduce their problematically high viscosity and lower their high price. Understanding the distinct effects of water on the properties of ILs/DESs is highly important. In this review, we collect published experimental and theoretical results for IL/DES–H2O systems at varied water concentrations and analyze them. Results from mechanistic studies, thermodynamic modelling and advanced experiments are collected and critically discussed. Six commonly studied IL/DES–H2O systems were selected to map experimental observations onto microscopic results obtained in mechanistic studies. A great variety of distinct contours of the excess properties can be observed over the entire compositional range, indicating that the properties of IL/DES–H2O systems are highly unpredictable. Mechanistic studies clearly demonstrate that the added H2O rapidly changes the heterogeneous 3D structures of pure ILs/DESs, leading to very different properties and behaviour. There are similarities between aqueous electrolytes and IL/DES solutions but the bulky and asymmetric organic cations in ILs/DESs do not conform to the standard salt dissolution and hydration concepts. Thermodynamic modelling previously assumes ILs/DESs to be either a neutral ion-pair or completely dissociated ions, neglecting specific ion hydration effects. A new conceptual framework is suggested for thermodynamic modelling of IL/DES–H2O binary systems to enable new technologies for their practical applications.

Journal ArticleDOI
TL;DR: In this paper, the ultrathin 2D MXene membrane with thickness down to several tens of nanometers was developed for pervaporation desalination by stacking synthesized atomic-thin MXene nanosheets.

Journal ArticleDOI
TL;DR: A simple solvothermal method to synthesize a series of MoS2 nanosheets@nitrogen-doped graphene composites is developed, demonstrating the significance in surface-controlled pseudocapacitance contribution at the high rate and offering some meaningful preparation and investigation experiences for designing electrode materials for commercial sodium-ion batteries with favorable performance.
Abstract: Transition-metal disulfide with its layered structure is regarded as a kind of promising host material for sodium insertion, and intensely investigated for sodium-ion batteries. In this work, a simple solvothermal method to synthesize a series of MoS2 nanosheets@nitrogen-doped graphene composites is developed. This newly designed recipe of raw materials and solvents leads the success of tuning size, number of layers, and interplanar spacing of the as-prepared MoS2 nanosheets. Under cut-off voltage and based on an intercalation mechanism, the ultrasmall MoS2 nanosheets@nitrogen-doped graphene composite exhibits more preferable cycling and rate performance compared to few-/dozens-layered MoS2 nanosheets@nitrogen-doped graphene, as well as many other reported insertion-type anode materials. Last, detailed kinetics analysis and density functional theory calculation are also employed to explain the Na+ - storage behavior, thus proving the significance in surface-controlled pseudocapacitance contribution at the high rate. Furthermore, this work offers some meaningful preparation and investigation experiences for designing electrode materials for commercial sodium-ion batteries with favorable performance.


Journal ArticleDOI
TL;DR: This research successfully demonstrated the possibility of PAW being an effective environmentally benign disinfectant, the activity of which is closely linked to the generation of peroxynitrite, providing much needed insights into the fundamental aspects ofPAW chemistry required for optimisation of the biochemical activity of PAw and translation of this decontamination strategy into real life applications.

Journal ArticleDOI
TL;DR: This review summarizes the overall state of ALE technology, including available selection pressures, methods, and their applications in microalgae for the improved production of lipids and carotenoids.
Abstract: Microalgae have drawn great attention as promising sustainable source of lipids and carotenoids. Their lipid and carotenoids accumulation machinery can be trigged by the stress conditions such as nutrient limitation or exposure to the damaging physical factors. However, stressful conditions often adversely affect microalgal growth and cause oxidative damage to the cells, which can eventually reduce the yield of the desired products. To overcome these limitations, two-stage cultivation strategies and supplementation of growth-promoting agents have traditionally been utilized, but developing new highly adapted strains is theoretically the simplest strategy. In addition to genetic engineering, adaptive laboratory evolution (ALE) is frequently used to develop beneficial phenotypes in industrial microorganisms during long-term selection under specific stress conditions. In recent years, many studies have gradually introduced ALE as a powerful tool to improve the biological properties of microalgae, especially for improving the production of lipid and carotenoids. In this review, strategies for the manipulation of stress in microalgal lipids and carotenoids production are summarized and discussed. Furthermore, this review summarizes the overall state of ALE technology, including available selection pressures, methods, and their applications in microalgae for the improved production of lipids and carotenoids.

Journal ArticleDOI
TL;DR: Multi-resonance induced by boron and nitrogen atoms in opposite resonance positions endows a thermally activated delayed fluorescence (MR-TADF) emitter with a strikingly small full width at half maximum and excellent photoluminescence quantum yield of up to 97.48 %.
Abstract: Multi-resonance induced by boron and nitrogen atoms in opposite resonance positions endows a thermally activated delayed fluorescence (MR-TADF) emitter with a strikingly small full width at half maximum of only 26 nm and excellent photoluminescence quantum yield of up to 97.48 %. The introduction of a carbazole unit in the para position of the B-substituted phenyl-ring can significantly boost up the resonance effect without compromising the color fidelity, subsequently enhancing the performances of the corresponding pure blue TADF-OLED, with an outstanding external quantum efficiency (EQE) up to 32.1 % and low efficiency roll-off, making it one of the best TADF-OLEDs in the blue region to date. Furthermore, utilizing this material as host for a yellow phosphorescent emitter, the device also shows a significantly reduced turn-on voltage of 3.2 V and an EQEmax of 22.2 %.

Journal ArticleDOI
TL;DR: In this article, the nitrogen vacancies located at the uncondensed terminal NHx lattice sites were conducive to the enhancement of optical absorption, the improvement of the separation efficiency of the photogenerated charge carrier and the increase of surface area, which was beneficial to the photocatalytic oxidation process.
Abstract: Vacancy defect in the semiconductors plays an important role in the improvement of the electronic structure and the increase of specific reaction sites for reactant molecules, and consequently enhancing the photocatalytic activity of semiconductor photocatalysts. Through high-temperature thermal condensation of a nitric acid-pretreated melamine precursor, nitrogen vacancies were successfully introduced in the framework of g-C3N4. The nitrogen vacancies located at the uncondensed terminal NHx lattice sites were conducive to the enhancement of optical absorption, the improvement of the separation efficiency of the photogenerated charge carrier and the increase of surface area, which was beneficial to the photocatalytic oxidation process. More significantly, the novel CNNA(X) were used as efficient photocatalysts in the green process of aromatic aldehydes from the photocatalytic selective oxidation of aromatic alcohols and the photocatalytic degradation of organic pollutants. CNNA(X) samples exhibited enhanced photocatalytic activity and excellent recyclability and stability. The 68.3% benzyl alcohol conversion and almost 100% selectivity was observed for the CNNA (0.9) photocatalyst, higher than that of pure g-C3N4. Meanwhile, CNNA (0.9) showed superior photocatalytic degradation performance of organic dyes (RhB and MO). Furthermore, the underlying photocatalytic oxidation mechanism was proposed by the controlled experiments using radical scavengers.

Journal ArticleDOI
TL;DR: In this article, the authors provide a summary of recent progress in nitrogen-doped simple/complex oxides for photocatalysis, and some useful guidelines for the future development are discussed.

Journal ArticleDOI
TL;DR: The results demonstrate that the flexible pressure sensor based on the functional-sponge is a promising candidate for healthcare monitoring and wearable circuitry in artificial intelligence.
Abstract: High-performance stretchable and wearable electronic skins (E-skins) with high sensitivity and a large sensing range are urgently required with the rapid development of the Internet of things and artificial intelligence. Herein, a reduced graphene oxide (rGO)/polyaniline wrapped sponge is prepared via rGO coating and the in situ synthesis of polyaniline nanowires (PANI NWs) on the backbones of sponge for the fabrication of pressure sensors. From the as-prepared flexible sensor, tunable sensitivity (0.042 to 0.152 kPa-1), wide working range (0-27 kPa), fast response (∼96 ms), high current output (∼300 μA at 1 V), frequency-dependent performance reliable repeatability (∼9000 cycle) and stable signal waveform output can be readily obtained. In addition to tiny physiological activities (voice recognition, swallowing, mouth opening, blowing and breath), robust human motions (finger bending, elbow movement and knee squatting-arising) can also be detected in real-time by the flexible sensors based on rGO/polyaniline wrapped sponge. All the results demonstrate that the flexible pressure sensor based on the functional-sponge is a promising candidate for healthcare monitoring and wearable circuitry in artificial intelligence.

Journal ArticleDOI
TL;DR: In this paper, a highly concentrated ink containing two-dimensional δ-MnO2 nanosheets with an average lateral size of 89"nm and around 1"n thickness was used.

Journal ArticleDOI
TL;DR: In this article, the authors systematically analyse the recent developments in the PTFE membrane formation and modification techniques and provide their perspectives on the future research directions for the preparation, modification, and application of porous poly(tetrafluoroethylene) (PTFE) membrane.

Journal ArticleDOI
01 Jun 2018-Small
TL;DR: The recent progress of organic dye-based NPs for cancer phototheranostic applications is summarized, which extends the anticancer arsenal and holds promise for clinical uses in the near future.
Abstract: Phototheranostics, which simultaneously combines photodynamic and/or photothermal therapy with deep-tissue diagnostic imaging, is a promising strategy for the diagnosis and treatment of cancers. Organic dyes with the merits of strong near-infrared absorbance, high photo-to-radical and/or photothermal conversion efficiency, great biocompatibility, ready chemical structure fine-tuning capability, and easy metabolism, have been demonstrated as attractive candidates for clinical phototheranostics. These organic dyes can be further designed and fabricated into nanoparticles (NPs) using various strategies. Compared to free molecules, these NPs can be equipped with multiple synergistic functions and show longer lifetime in blood circulation and passive tumor-targeting property via the enhanced permeability and retention effect. In this article, the recent progress of organic dye-based NPs for cancer phototheranostic applications is summarized, which extends the anticancer arsenal and holds promise for clinical uses in the near future.

Journal ArticleDOI
TL;DR: In this article, detonation nanodiamonds were constructed as a characteristic core/shell structure in the sp 2 /sp 3 configuration to demonstrate the intrinsic correlation between the structure and catalysis.
Abstract: Nanocarbons in molecular configurations of sp 2 /sp 3 present versatile structural and electronic properties, exhibiting a complexity in the structure-activity chemistry. In this work, we employed detonation nanodiamonds constructed as a characteristic core/shell structure in the sp 2 /sp 3 configuration to demonstrate the intrinsic correlation between the structure and catalysis. Annealed detonation nanodiamonds were found to show a superb activity for catalytic peroxymonosulfate activation and organic oxidation. A synergistic effect of charge transport was discovered at the interface to construct an electron-enriched carbon surface that further promoted the catalytic activity evidenced by the density functional theory (DFT) calculations. More importantly, both experimental results and theoretical predictions revealed that the catalytic oxidation via peroxymonosulfate (PMS) activation was intimately dependent on the proportion of graphitic carbon layer in the sp 2 /sp 3 configurations. The increase of graphitic layers on nanodiamonds would alter the PMS activation from a radical-based reaction to a nonradical pathway for catalytic oxidation. The novel catalytic properties of tunable oxidative potentials from carbocatalysis may simulate fascinating prospects for environmental catalysis and organic synthesis.

Journal ArticleDOI
TL;DR: In this article, the authors demonstrate perovskite-polymer bulk heterostructure LEDs exhibiting record-high external quantum efficiencies exceeding 20%, and an EL half-life of 46 hours under continuous operation.
Abstract: Perovskite-based optoelectronic devices have gained significant attention due to their remarkable performance and low processing cost, particularly for solar cells. However, for perovskite light-emitting diodes (LEDs), non-radiative charge carrier recombination has limited electroluminescence (EL) efficiency. Here we demonstrate perovskite-polymer bulk heterostructure LEDs exhibiting record-high external quantum efficiencies (EQEs) exceeding 20%, and an EL half-life of 46 hours under continuous operation. This performance is achieved with an emissive layer comprising quasi-2D and 3D perovskites and an insulating polymer. Transient optical spectroscopy reveals that photogenerated excitations at the quasi-2D perovskite component migrate to lower-energy sites within 1 ps. The dominant component of the photoluminescence (PL) is primarily bimolecular and is characteristic of the 3D regions. From PL quantum efficiency and transient kinetics of the emissive layer with/without charge-transport contacts, we find non-radiative recombination pathways to be effectively eliminated. Light outcoupling from planar LEDs, as used in OLED displays, generally limits EQE to 20-30%, and we model our reported EL efficiency of over 20% in the forward direction to indicate the internal quantum efficiency (IQE) to be close to 100%. Together with the low drive voltages needed to achieve useful photon fluxes (2-3 V for 0.1-1 mA/cm2), these results establish that perovskite-based LEDs have significant potential for light-emission applications.

Journal ArticleDOI
TL;DR: A series of molecules with unique dynamic ultralong organic phosphorescence features, enabled by manipulating intermolecular interactions through UV light irradiation, are reported on to provide unique insight into dynamic molecular motion for optical processing and expand the scope of smart-response materials for broader applications.
Abstract: Smart materials with ultralong phosphorescence are rarely investigated and reported. Herein we report on a series of molecules with unique dynamic ultralong organic phosphorescence (UOP) features, enabled by manipulating intermolecular interactions through UV light irradiation. Our experimental data reveal that prolonged irradiation of single-component organic phosphors of PCzT, BCzT, and FCzT under ambient conditions can activate UOP with emission lifetimes spanning from 1.8 to 1330 ms. These phosphors can also be deactivated back to their original states with short-lived phosphorescence by UV irradiation for 3 h at room temperature or through thermal treatment. Additionally, the dynamic UOP was applied successfully for a visual anti-counterfeiting application. These findings may provide unique insight into dynamic molecular motion for optical processing and expand the scope of smart-response materials for broader applications.