Latest ArticlesWe demonstrate hole-transport-layer-free light-emitting diodes (LEDs) based on solution-processed multiple-quantum-well (MQW) perovskite. The MQW perovskite can self-assemble to a unique structure of vertically graded distribution with two-dimensional layered perovskite covered by three-dimensional-like perovskite at top, which can naturally form a barrier of electron transporting to the anode interface, thereby enhancing the charge capture efficiency. This leads to hole-transport-layer-free MQW perovskite LEDs reaching an external quantum efficiency (EQE) of 9.0% with emission peak at 528 nm, which is over 6 times of LEDs based on three-dimensional perovskite with the same device structure, representing the record EQE of hole-transport-layer-free perovskite LED.
Pomalidomide is an immunomodulatory agent (IMiD) that has been approved by the US Food and Drug Administration (FDA) for clinical treatment of patients with multiple myeloma. In this work, we developed a sensitive and validated LC-MS/MS method for high-throughput determination of pomalidomide over the range of 1.006–100.6 ng/mL (R2 = 0.9991) in human plasma and pharmacokinetic studies. A liquid-liquid extraction method using ethyl acetate was applied to extract pomalidomide and afatinib (as an internal standard, IS) from human plasma. Chromatographic separation was performed on a Hedera ODS column (150 mm × 2.1 mm, 5 µm) with security guard C18 column (4 mm × 2.0 mm) at 40 ℃. Methanol and 10 mmol/L aqueous solution of ammonium acetate containing 0.1% formic acid were used as a gradient elution mobile phase, and the flow rate was 0.4 mL/min. A triple quadruple tandem mass spectrometer using multiplex reaction monitoring mode (MRM) with electrospray ionization (ESI) positive ionization was employed. The precursor to product ion transitions for the quantitative analysis of pomalidomide and the IS were m/z 274.2→163.1 and m/z 486.1 → 371.1, respectively. This established method has been validated according to regulatory guideline, and the results were all within the acceptance criteria. The validated LC-MS/MS method was successfully applied to analyze samples obtained from clinical pharmacokinetics study after oral administration of pomalidomide (4 mg) capsules in human.
To address the challenge of treating complex pollutants containing heavy metals and organic compounds, a phenanthroline/TiO2 nanocomposite with rich oxygen vacancy defects was synthesized to integrate the functions of pollutant detection, adsorption, and photocatalytic degradation. The results showed that the nanocomposite could adsorb Cr3+ and the process could be transduced into a colorimetric signal for qualitative and quantitative detection. The adsorbed heavy metal also exhibited a synergistically enhanced photocatalytic degradation of a model organic pollutant under visible light. The simultaneous adsorption, detection, and photocatalysis could reduce the multifarious operations and high cost of traditional environmental remediation methods, indicating a strong application potential for the nanocomposite.
Electrocatalysis plays an increasingly important role in converting atmospheric molecules (e.g., N2, CO2 and H2O) to value-added products (e.g., NH3, C2H4 and H2). However, developing a simple strategy for preparing catalysts with high performance for the effective conversion of clean energy is still full of challenges. Herein, we describe a straightforward, one-step reduction method to achieve the formation of Pt nanoparticles (NPs) and the vacancy engineering of TiO2–x nanofibers (NFs) simultaneously, which can be accomplished in 5 min. Furthermore, a Pt/TiO2–x nanofibrous aerogel (NA) with an ordered cellular architecture is prepared through a directional freezing technology. The Pt/TiO2–x NA with excellent mechanical properties can be made into a self-supporting electrode for electrocatalytic N2 reduction reaction (NRR), showing high NH3 yield rate (4.81 × 10–10 mol/s cm–2) and Faraday efficiency (14.9%) at –0.35 V vs. RHE.
Lithium metal is deemed as an ideal anode material in lithium-ion batteries because of its ultrahigh theoretical specific capacity and the lowest redox potential. However, the rapid capacity attenuation and inferior security resulting from the dendritic lithium growth severely limit its commercialization. Herein a novel hybrid gel polymer electrolyte (GPE) based on electrospun lithium sulfonated polyoxadiazole (Li-SPOD) nanofibrous membrane swelled by lithium bis(trifluoromethanesulfonyl)imide (LiTFSI) ether liquid electrolyte is proposed to address the issue of lithium dendrites. The Li-SPOD membrane synthesized by a simple one-pot method exhibits excellent mechanical strength and thermal resistance due to its high molecular weight and rigid backbone. The electron-withdrawing oxadiazole ring and oxadiazole ring-Li+ complex, and N, O heteroatoms with lone pairs of electrons in Li-SPOD macromolecular chains facilitate the dissociation of -SO3Li group and Li+ transference. The hybrid Li-SPOD GPE exhibits both a high lithium-ion transference number (0.64) and high ionic conductivity (2.03 mS/cm) as well as superior interfacial compacity with lithium anodes. The LiFePO4-Li cell using this novel GPE can operate steadily at 2 C for 300 cycles, remaining a high discharge capacity of 125 mAh/g and dendrite-free anode. Remarkable performance improvements for the Li-Li and Cu-Li cells are also presented.
Developing non-noble-metal oxygen evolution reaction (OER) electrocatalysts with high performance is critical to electrocatalytic water splitting. In this work, we fabricated CoFe-layered double hydroxide (LDH) nanowire arrays on graphite felt (CoFe-LDH/GF) via a hydrothermal method. The CoFe-LDH/GF, as a robust integrated 3D OER anode, exhibits excellent catalytic activity with the need of low overpotential of 252 and 285 mV to drive current densities of 10 and 100 mA/cm2 in 1.0 mol/L KOH, respectively. In addition, it also maintains electrochemical durability for at least 24 h. This work would open up avenues for the development of GF like attractive catalyst supports for oxygen evolution applications.
The recombination of charge carriers arriving from the random charge movement in semiconductor photocatalysts greatly limits the practical application of solar-driven H2 evolution. The design of photocatalytic systems with spatially oriented charge-transfer is a promising route to achieve high charge-separation efficiency for photocatalysts. Herein, novel sea-urchin-like ReS2 nanosheet/TiO2 nanoparticle heterojunctions (SURTHs) are constructed. The unique sea-urchin-like structure endows the ReS2 cocatalyst with an unusual charge edge-collection effect, which leads to a significant acceleration of charge separation and transfer, as evidenced by the well-designed selective photodeposition of Pt quantum dots in SURTHs. The markedly improved charge transfer capacity contributes to a high photocatalytic H2 evolution rate of 3.71 mmol h-1 g-1 for SURTHs (an apparent quantum efficiency (AQE) of 16.09%), up to 231.9 times by contrast with that of P25 TiO2. This work would provide a new platform for designing the high-efficiency cocatalyst/photocatalyst system with excellent charge transfer capacity.
Three bench-stable difluoromethylene phosphonate hydrazones were prepared from simple diethyl(difluoromethyl)phosphonate within two steps in good yields. The [3 + 2] cycloaddition reaction of these diazo precursors with aryl diazonium salts has been accomplished under metal-free conditions with exclusive regioselectivity. This transformation provides practical access to a broad panel of 2-aryl-2H-tetrazol-5-yl difluoromethylene phosphonates, including the corresponding derivatives of amino acid (phenylalanine) and drug cores (Pomalidomide and Lapatinib fragment).
Developing selectively targeted photothermal agents to reduce side effects in photothermal therapy remains a great challenge. Inspired by the key role of endoplasmic reticulum in the protein synthesis and intracellular signal transduction, particularly for the immunogenic cell death induced by endoplasmic reticulum stress, we developed an endoplasmic reticulum-targeted organic photothermal agent (Ts-PT-RGD) for enhancing photothermal therapy of tumor. The photothermal agent was covalently attached with 4-methylbenzenesulfonamide and cyclic Arg-Gly-Asp (cRGD) peptide for realizing the targeting of endoplasmic reticulum and tumor cell. Owing to its amphiphilic properties, it readily self-assembles in water to form nanoparticles. The photothermal agent possesses excellent photophysical properties and biological compatibility. In vitro and in vivo experiments demonstrate that it can actively target endoplasmic reticulum and effectively ablate tumor with near-infrared laser.
Various enzymatic reactions or enzymatic cascade reactions occur efficiently in biological microsystems due to space constraints or orderly transfer of intermediate products. Inspired by this, the horseradish peroxidase (HRP)-like nanozyme (Fe-aminoclay) was in situ synthesized on the surface of alkali-activated halloysite nanotubes and the natural enzyme (glucose oxidase, GOx) was immobilized on it to construct a high-efficiency GOx-FeAC@AHNTs cascade nanoreactor. In which, FeAC@AHNTs can not only be used as a carrier for immobilized enzymes, but also help its catalytic activity to cooperate with glucose oxidase in a cascade reaction. The microcompartments and substrate channel effect of this enzyme-nanozyme microsystem exhibit a superior catalytic performance than that of natural enzyme system, and exhibits excellent long-term stability and recyclability. Subsequently, the GOx-FeAC@AHNTs cascade nanoreactor was employed as a glucose colorimetric platform, which displayed a low detection limit (0.47 µmol/L) in glucose detection. This enzyme-nanoenzyme nanoreactor provides a simple and effective example for constructing a multi-enzyme system with limited space, and lays the foundation for subsequent research in the fields of biological analysis and catalysis.