CH3NH3PbI3‐xClx is a commonly used chemical formula to represent the methylammonium lead halide perovskite fabricated from mixed chlorine‐ and iodine‐containing salt precursors. Despite the rapid ...progress in improving its photovoltaic efficiency, fundamental questions remain regarding the atomic ratio of Cl in the perovskite as well as the reaction mechanism that leads to its formation and crystallization. In this work we investigated these questions through a combination of chemical, morphological, structural and thermal characterizations. The elemental analyses reveal unambiguously the negligible amount of Cl atoms in the CH3NH3PbI3‐xClx perovskite. By studying the thermal characteristics of methylammonium halides as well as the annealing process in a polymer/perovskite/FTO glass structure, we show that the formation of the CH3NH3PbI3‐xClx perovskite is likely driven by release of gaseous CH3NH3Cl (or other organic chlorides) through an intermediate organometal mixed halide phase. Furthermore, the comparative study on CH3NH3I/PbCl2 and CH3NH3I/PbI2 precursor combinations with different molar ratios suggest that the initial introduction of a CH3NH3+ rich environment is critical to slow down the perovskite formation process and thus improve the growth of the crystal domains during annealing; accordingly, the function of Cl− is to facilitate the release of excess CH3NH3+ at a relatively low annealing temperatures.
To understand theformation mechanism of CH3NH3PbI3–xClx perovskite, two testing structures, perovskite (precursor mixture)/FTO and PMMA (polymethyl methacrylate)/perovskite (precursor mixture)/FTO, are designed. The different annealing results of these two structures suggest that the formation of CH3NH3PbI3–xClx perovskite is likely driven by the release of gaseous CH3NH3Cl through an intermediate organolead mixed halide phase.
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BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SBCE, SBMB, UL, UM, UPUK
With the rapid development of portable electronic devices and electric vehicles, lithium-ion batteries (LIBs) are being used extensively as clean and efficient power sources. Among the various anode ...materials being explored for use in LIBs, Ge has attracted significant attention owing to its high theoretical specific capacity. However, low electronic conductivity, relative poor Li-ion mobility, large volume expansion impede its commercial application. Herein, we synthesize a single-phase AlGeP solid solution through a facile high-energy ball milling of the raw materials of Al, P and Ge. The ternary AlGeP exhibits superior Li-storage properties than the single-component phase of Ge in terms of longer cycling stability, and faster rate performance profiting from its faster electronic conductivity confirmed by electrochemical impedance spectra, and higher Li-ion mobility confirmed by galvanostatic intermittent titration technique measurements. Moreover, we further promote the electrochemical Li-storage properties of the ternary AlGeP through carbon modification which accommodate the volume expansion and improve the electronic conductivity. Broadly this work will stimulate more research interest on ternary all-lithium-reactive compounds in the energy storage field.
•Synthesis of AlGeP solid solution by high energy ball milling.•AlGeP solid solution exhibits better electrochemical performance than Ge and Al+Ge+P mixture.•Abundant lithium storage products can be generated during lithium storage.•The AlGeP/C electrode exhibits a high capacity of 312 mAh g−1 at a current density of 20 A g−1.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
Selective attention is an efficient processing strategy to allocate computational resources for pivotal optical information. However, the hardware implementation of selective visual attention in ...conventional intelligent system is usually bulky and complex along with high computational cost. Here, programmable ferroelectric bionic vision hardware to emulate the selective attention is proposed. The tunneling effect of photogenerated carriers are controlled by dynamic variation of energy barrier, enabling the modulation of memory strength from 9.1% to 47.1% without peripheral storage unit. The molecular polarization of ferroelectric P(VDF-TrFE) layer enables a single device not only multiple nonvolatile states but also the implementation of selective attention. With these ferroelectric devices are arrayed together, UV light information can be selectively recorded and suppressed the with high current decibel level. Furthermore, the device with positive polarization exhibits high wavelength dependence in the image attention processing, and the fabricated ferroelectric sensory network exhibits high accuracy of 95.7% in the pattern classification for multi-wavelength images. This study can enrich the neuromorphic functions of bioinspired sensing devices and pave the way for profound implications of future bioinspired optoelectronics.
The identification of surgical non-small cell lung cancer (NSCLC) patients with poor prognosis is a priority in clinical oncology because of their high 5-year mortality. This meta-analysis explored ...the prognostic value of maximal standardized uptake value (SUVmax), metabolic tumor volume (MTV) and total lesion glycolysis (TLG) on disease-free survival (DFS) and overall survival (OS) in surgical NSCLC patients.
MEDLINE, EMBASE and Cochrane Libraries were systematically searched until August 1, 2015. Prospective or retrospective studies that evaluated the prognostic roles of preoperative 18F-FDG PET/CT with complete DFS and OS data in surgical NSCLC patients were included. The impact of SUVmax, MTV or TLG on survival was measured using hazard ratios (HR). Sub-group analyses were performed based on disease stage, pathological classification, surgery only and cut-off values.
Thirty-six studies comprised of 5807 patients were included. The combined HRs for DFS were 2.74 (95%CI 2.33-3.24, unadjusted) and 2.43 (95%CI: 1.76-3.36, adjusted) for SUVmax, 2.27 (95%CI 1.77-2.90, unadjusted) and 2.49 (95%CI 1.23-5.04, adjusted) for MTV, and 2.46 (95%CI 1.91-3.17, unadjusted) and 2.97 (95%CI 1.68-5.28, adjusted) for TLG. The pooled HRs for OS were 2.54 (95%CI 1.86-3.49, unadjusted) and 1.52 (95%CI 1.16-2.00, adjusted) for SUVmax, 2.07 (95%CI 1.16-3.69, unadjusted) and 1.91 (95%CI 1.13-3.22, adjusted) for MTV, and 2.47 (95%CI 1.38-4.43, unadjusted) and 1.94 (95%CI 1.12-3.33, adjusted) for TLG. Begg's test detected publication bias, the trim and fill procedure was performed, and similar HRs were obtained. The prognostic role of SUVmax, MTV and TLG remained similar in the sub-group analyses.
High values of SUVmax, MTV and TLG predicted a higher risk of recurrence or death in patients with surgical NSCLC. We suggest the use of FDG PET/CT to select patients who are at high risk of disease recurrence or death and may benefit from aggressive treatments.
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DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
•A novel ternary GaAl2P3 compound with cation-mixing zinc sulfide was synthesized for the first time.•Cation-mixing GaAl2P3 compound exhibits better Li-storage properties compared with pre-determined ...precursors.•Various characterizations including in-situ XRD were used to analyze the lithium storage mechanism.
Aluminum (Al) is an ideal anode material due to its large theoretical Li-storage capacity of 993 mA h g−1 corresponded to the binary alloy of LiAl due to its light atomic weight, rich reserve, and mature industrial application. However, the large volume expansion and relatively sluggish Li-ion diffusion result in inferior performance, hindering its commercial application. Herein, through simple mechanochemical reactions, we prepare a new ternary compound of GaAl2P3, whose crystal structure is the cation-mixed cubic ZnS structure according to XRD refinement. Disordered lattice and all-lithium-reactive constituent elements enable the GaAl2P3 compound to store Li-ions in a fast and stable manner. GaAl2P3 compound offers a reversible capacity of 1,485 mA h g−1 with an initial Coulombic efficiency of 90 % based on a reversible Li-storage mechanism integrating an intercalation reaction and followed conversion reaction as confirmed by in-situ XRD and Raman characterization. Its carbon composite delivers 880 mA h g−1 capacity after 300 cycles at 1,000 mA g−1 and 575 mA h g−1 capacity at 10,000 mA g−1, surpassing most reported Al-based anodes studied before, holding the promise to be applied in real word. Broadly, this work will arouse immediate interest in energy storage of aluminum-based compounds.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
A novel and efficient method for the synthesis of difluoroalkylated benzofuran, benzothiophene, and indole derivatives via palladium-catalyzed aryldifluoroalkylation of 1,6-enynes with ethyl ...difluoroiodoacetate and arylboronic acids has been established. High reaction efficiency, mild conditions, broad substrate scope, and good functional group tolerance are the features of this protocol. Notablely, the resultant products can be smoothly converted into CF2-containing benzofurans, benzothiophenes and indoles through an isomerization process catalyzed by Fe(OTf)3.
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IJS, KILJ, NUK, PNG, UL, UM
An unprecedented copper-catalyzed multicomponent radical-based reaction involving alkenes, P(O)H compounds, sulfur powder, and Togni reagent II at room temperature has been developed. A variety of ...highly functionalized CF3-containing S-alkyl phosphorothioates can be directly prepared from a wide range of activated and unactivated alkenes. Moreover, this protocol highlights its potential in the late-stage functionalization of complex molecules and opens up a new avenue for the construction of C(sp3)–S–P bonds.
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IJS, KILJ, NUK, PNG, UL, UM
The development of low-cost, high-performance anode materials for Li-ion batteries (LIBs) is imperative to meet the ever-increasing demands for advanced power sources. Here we report our findings on ...the design, synthesis, and characterization of a new cation-disordered ZnSiP
2
anode. When tested in LIBs, the disordered phase of ZnSiP
2
demonstrates faster reaction kinetics and higher energy efficiency than the cation-ordered phase of ZnSiP
2
. The superior performance is attributed to the greater electronic and ionic conductivity and better tolerance against volume variation during cycling, as confirmed by theoretical calculations and experimental measurements. Moreover, the cation-disordered ZnSiP
2
/C composite exhibits excellent cycle stability and superior rate capability. The performance surpasses all reported multi-phase anodes studied. Further, a number of the cation-disordered phases in the Zn(Cu)-Si-P family with a wide range of cation ratios show similar performance, achieving large specific capacities and high first-cycle coulombic efficiency while maintaining desirable working potentials for enhanced safety.
Cation-disordered Zn(Cu)-Si-P family materials demonstrate better Li-storage performance than the cation-ordered ZnSiP
2
phase due largely to faster electronic and ionic conductivity and better tolerance to volume change during cycling, as confirmed by DFT calculations and experimental measurements.
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•Ternary GaSiP solid solution with a disordered lattice and liquid metallic phase is synthesized.•Ternary GaSiP presents ultrafast Li-ion and electronic conductivity.•Ternary GaSiP ...anode demonstrates excellent Li-storage performances.
Silicon (Si) has become the most promising next-generation anode to replace commercial graphite for Li-ion batteries (LIBs) profiting from its large reversible capacity of 4,200 mA h g−1. However, its sluggish reaction kinetics and large volume effect need to be resolved. Herein, we prepare a ternary GaSiP solid solution with a disordered lattice by a facile mechanochemistry method. As anodes of LIBs, the GaSiP provides a reversible capacity of 1,527 mA h g−1 at 100 mA g−1 with an initial Coulombic efficiency (ICE) of 90.8% based on the reversible Li-storage mechanism integrated intercalation and subsequent conversion processes as confirmed by crystallography characterization and electrochemical measurements. Importantly, the GaSiP carbon composite presents a long cycling stability of maintaining 1,362 mA h g−1 after 50 cycles at 0.1 A g−1, and 75% capacity retention rate after 1,200 cycles at 2 A g−1, and a high-rate performance of remaining 440 mA h g−1 at 20 A g−1. Broadly, this work opens the door to develop ternary phosphides with disordered lattice and liquid metallic phase using for electrochemical energy conversion and storage.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
•A novel ternary layered BiSbSi compound with a disordered lattice was synthesized for the first time.•The layered and disordered lattice endows the BiSbSi with ultrafast electronic conductivity and ...Li-ionic diffusion capability.•The BiSbSi compound presents significantly faster reaction kinetics than Si counterparts.
Silicon has become the most promising anode material for industrial application to replace the currently utilized graphite because of its large capacity and abundant reserves. However, its poor electronic conductivity and slow Li-ionic diffusion capability along with severe volume expansion impede its high-rate performace. To resolve these issues, we develop a ternary BiSbSi compound with a layered lattice, which presents significantly improved reaction kinetics of 300 mA h g−1 at 20 A g−1 enabled by faster electronic conduction and lithium ion diffusion and simultaneously reduce the volume variation, thus leading to longer cycling stability of remaining 561 mA h g−1 after 1000 cycles at 2 A g−1, compared with Si counterparts. Broadly the ternary layered Si-based anodes hold great promises to be applied in the near future.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
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