Highly luminescent and stable CsPbBr3 perovskite quantum dots modified by phosphine ligands

All-inorganic cesium lead halide perovskite quantum dots (QDs) have been a promising candidate for optoelectronic devices in recent years, such as light-emitting diodes, photodetectors and solar cells, owing to their superb optoelectronic properties. Still, the stability issue of nanocrystals is a bottleneck for their practical application. Herein, we report a facile method for the synthesis of a series of phosphine ligand modified CsPbBr₃ QDs with high PL intensity. By introducing organic phosphine ligands, the tolerance of CsPbBr₃ QDs to ethanol, water and UV light was dramatically improved. Moreover, the phosphine ligand modified QD films deposited on the glass subtracts exhibit superior PL intensity and optical stability to those of pristine QD based films.

     

Highly effective H2/D2 separation in a stable Cu-based metal-organic framework

A three-dimensional copper metal—organic framework with the rare chabazite (CHA) topology namely FJI-Y11 has been constructed with flexibly carboxylic ligand 5,5′-[(1,4-phenylenebis(methylene))bis(oxy)]diisophthalic acid (H₄L). FJI-Y11 exhibits high water stability with the pH range from 2 to 12 at temperature as high as 373 K. Importantly, FJI-Y11 also shows high efficiency of hydrogen isotope separation using dynamic column breakthrough experiments under atmospheric pressure at 77 K. Attributed to its excellent structural stability, FJI-Y11 possesses good regenerated performance and maintains high separation efficiency after three cycles of breakthrough experiments.

     

Photodeposition fabrication of hierarchical layered Co-doped Ni oxyhydroxide (NixCo1−xOOH) catalysts with enhanced electrocatalytic performance for oxygen evolution reaction

Highly active, durable and inexpensive oxygen evolution reaction (OER) catalysts are crucial for achieving practical and high-efficiency water splitting. Herein, hierarchical interconnected Ni_xCo_1−xOOH nanosheet arrays supported on TiO₂/Ti substrate have been fabricated through a facile photodeposition method. Compared with pristine NiOOH, the obtained Ni_xCo_1−xOOH nanosheet arrays possess larger exposed electrochemical active surface area, faster transfer and collection of electrons and stronger electronic interaction, showing a low overpotential of 350 mV at a current density of 10 mA·cm⁻² and a small Tafel slope of 41 mV·dec⁻¹ in basic solutions, with the OER performance superior to pristine NiOOH and most Ni-based catalysts. Furthermore, the Ni_xCo_1−xOOH electrode demonstrates excellent stability at the current density of 10 mA·cm⁻² for 24 hours, which is attributed to the structural maintenance caused by the good adhesion of the catalyst and the substrate. Our study provides an alternative approach for the rational design of highly active and promising OER electrocatalysts.

     

An electrodeposition approach to metal/metal oxide heterostructures for active hydrogen evolution catalysts in near-neutral electrolytes

Neutral water splitting is attractive for its use of non-corrosive and environmentally friendly electrolytes. However, catalyst development for hydrogen and oxygen evolution remains a challenge under neutral conditions. Here we report a simple electrodeposition and reductive annealing procedure to produce a highly active Ni-Co-Cr metal/metal oxide heterostructured catalyst directly on Ni foam. The resulting electrocatalyst for hydrogen evolution reaction (HER) requires only 198 mV of overpotential to reach 100 mA/cm² in 1 M potassium phosphate (pH = 7.4) and can operate for at least two days without significant performance decay. Scanning transmission electron microscopy coupled with electron energy loss spectroscopy (STEM-EELS) imaging reveals a Ni-Co alloy core decorated with blended oxides layers of NiO, CoO and Cr₂O₃. The metal/metal oxide interfaces are suggested to be responsible for the high HER activity.

     

Recent advances in the synthesis and applications of anisotropic carbon and silica-based nanoparticles

Colloidal nanoparticles with anisotropic architectures have attracted a variety of interest and attention due to different physical and chemical properties compared with the isotropic counterparts, making them promising candidates in many fundamental studies and practical applications. Particularly, carbon and silica-based anisotropic nanoparticles can be one stand out by combing both intrinsic merits of carbons and silica, such as structural stability, biocompatibility, large surface area, and ease of functionalization with the anisotropic structural complexity. In this review, we aim to provide an updated summary of the research related to the anisotropic carbon and silica-based nanostructures, covering both their synthesis and applications.

     

Graphene: A promising candidate for charge regulation in high-performance lithium-ion batteries

The development of rechargeable lithium-ion batteries (LIBs) is being driven by the ever-increasing demand for high energy density and excellent rate performance. Charge transfer kinetics and polarization theory, considered as basic principles for charge regulation in the LIBs, indicate that the rapid transfer of both electrons and ions is vital to the electrochemical reaction process. Graphene, a promising candidate for charge regulation in high-performance LIBs, has received extensive investigations due to its excellent carrier mobility, large specific surface area and structure tunability, etc. Recent progresses on the structural design and interfacial modification of graphene to regulate the charge transport in LIBs have been summarized. Besides, the structure-performance relationships between the structure of the graphene and its dedicated applications for LIBs have also been clarified in detail. Taking graphene as a typical example to explore the mechanism of charge regulation will outline ways to further understand and improve carbon-based nanomaterials towards the next generation of electrochemical energy storage devices.

     

A mini review on two-dimensional nanomaterial assembly

Two-dimensional (2D) nanomaterials have attracted a great deal of attention since the discovery of graphene in 2004, due to their intriguing physicochemical properties and wide-ranging applications in catalysis, energy-related devices, electronics and optoelectronics. To maximize the potential of 2D nanomaterials for their technological applications, controlled assembly of 2D nanobulding blocks into integrated systems is critically needed. This mini review summarizes the reported strategies of 2D materials-based assembly into integrated functional nanostructures, from in-situ assembly method to post-synthesis assembly. The applications of 2D assembled integrated structures are also covered, especially in the areas of energy, electronics and sensing, and we conclude with discussion on the remaining challenges and potential directions in this emerging field.

     

Ultrasonication-assisted and gram-scale synthesis of Co-LDH nanosheet aggregates for oxygen evolution reaction

Electrochemical water splitting (EWS) is a highly clean and efficient method for high-purity hydrogen production. Unfortunately, EWS suffers from the sluggish and complex oxygen evolution reaction (OER) kinetics at anode. At present, the efficient, stable, and low-cost non-precious metal based OER electrocatalyst is still a great and long-term challenge for the future industrial application of EWS technology. Herein, we develop a simple and fast approach for gram-scale synthesis of flower-like cobalt-based layered double hydroxides nanosheet aggregates by ultrasonic synthesis, which show outstanding electrocatalytic performance for the oxygen evolution reaction in alkaline media, such as preeminent stability, small overpotential of 300 mV at 10 mA·cm⁻² and small Tafel slope of 110 mV·dec⁻¹.

     

Origin of inhomogeneity in spark plasma sintered bismuth antimony telluride thermoelectric nanocomposites

Anisotropy and inhomogeneity are ubiquitous in spark plasma sintered thermoelectric devices. However, the origin of inhomogeneity in thermoelectric nanocomposites has rarely been investigated so far. Herein, we systematically study the impact of inhomogeneity in spark plasma sintered bismuth antimony telluride (BiSbTe) thermoelectric nanocomposites fabricated from solution-synthesized nanoplates. The figure of merit can reach 1.18, which, however, can be overestimated to 1.88 without considering the inhomogeneity. Our study reveals that the inhomogeneity in thermoelectric properties is attributed to the non-uniformity of porosity, textures and elemental distribution from electron backscatter diffraction and energy-dispersive spectroscopy characterizations. This finding suggests that the optimization of bulk material homogeneity should also be actively pursued in any future thermoelectric material research.

     

Nanovilli electrode boosts hydrogen evolution:A surface with superaerophobicity and superhydrophilicity

Although tremendous efforts have been paid on electrocatalysts toward efficient electrochemical hydrogen generation,breakthrough is still highly needed in the design and synthesis of wonderful non-precious-metal electrocatalyst.Herein,a nanovilli Ni2P electrode,which with superaerophobic and superhydropholic can significantly facilitate the mass and electron transfer was constructed via a facial morphology control strategy.Meanwhile,the substitution of sluggish oxygen evolution with urea oxidation,lowering the two-electrode cell voltage to only 1.48 volts to achieve a current density of 10 mA·cm^-2.Thus,the as-constructed electrode achieves the operation of hydrogen generation by an AA battery.This work sheds new light on the exploration of other high-efficient electrocatalysts for hydrogen generation by using intermittent clean energy.     

The fabrication and application of Ni-DNA nanowire-based nanoelectronic devices

DNA is a self-assembled, double stranded natural molecule that can chelate and align nickel ions between its base pairs. The fabrication of a DNA-guided nickel ion chain (Ni-DNA) device was successful, as indicated by the conducting currents exhibiting a Ni ion redox reaction-driven negative differential resistance effect, a property unique to mem-elements (1). The redox state of nickel ions in the Ni-DNA device is programmable by applying an external bias with different polarities and writing times (2). The multiple states of Ni-DNA-based memristive and memcapacitive systems were characterized (3). As such, the development of Ni-DNA nanowire device-based circuits in the near future is proposed.

     

Self-supporting Co0.85Se nanosheets anchored on Co plate as highly efficient electrocatalyst for hydrogen evolution reaction in both acidic and alkaline media

Electrocatalytic water splitting via hydrogen evolution reaction (HER) represents one of promising strategies to gain hydrogen energy. In current work, self-supporting Co_0.85Se nanosheets network anchored on Co plate (Co_0.85Se NSs@Co) is fabricated by employing easily tailorable Co metal plate as the source conductive substrate. The scalable dealloying and hydrothermal selenization strategy was employed to build one layer of three dimensional interlinking Co_0.85Se nanosheets network on the surface of Co plate. Benefiting from bulky integrated architecture and rich active sites, the as-made Co_0.85Se NSs@Co exhibits superior electrocatalytic activity and long-term catalytic durability toward HER. It only requires lower overpotentials of 121 and 162 mV to drive the current density of 10 mA·cm⁻² for hydrogen evolution in 0.5 M H₂SO₄ and 1 M KOH solution. Especially, no evident activity decay occurs upon 1,500 cycles or continuous test for 20 h at 10 mA·cm⁻² in both acidic and alkaline electrolytes. With the merits of exceptional performances, scalable production, and low cost, the self-supporting Co_0.85Se NSs@Co holds prospective application potential as stable and binder-free electrocatalysts for hydrogen generation in a wide range of electrolyte.

     

FeOOH quantum dots decorated graphene sheet: An efficient electrocatalyst for ambient N2 reduction

Electrochemical N₂ reduction offers a promising alternative to the Haber-Bosch process for sustainable NH₃ synthesis at ambient conditions, but it needs efficient catalysts for the N₂ reduction reaction (NRR). Here, we report that FeOOH quantum dots decorated graphene sheet acts as a superior catalyst toward enhanced electrocatalytic N₂ reduction to NH₃ under ambient conditions. In 0.1 M LiClO₄, this hybrid attains a large NH₃ yield rate and a high Faradaic efficiency of 27.3 µg·h⁻¹·mg⁻¹_cat. and 14.6% at −0.4 V vs. reversible hydrogen electrode, respectively, rivalling the current efficiency of all Fe-based NRR electrocatalysts in aqueous media. It also shows strong durability during the electrolytic process.

     

Interlayer-expanded MoS2 assemblies for enhanced electrochemical storage of potassium ions

Potassium-ion batteries are regarded as the low-cost alternative to lithium-ion batteries. However, their development is hampered by the lack of suitable electrode materials. In this work, we demonstrate that MoS₂ with expanded interlayers represents a promising candidate for the electrochemical storage of potassium ions. Hierarchical interlayer-expanded MoS₂ assemblies supported on carbon nanotubes are prepared via a straightforward solution method. The increased interlayer spacing not only enables the better accommodation of foreign ions, but also lowers the diffusion energy barrier and improves diffusion kinetics of ions. When investigated as the anode material of potassium ion batteries, our interlayer-expanded MoS₂ assemblies exhibit an excellent electrochemical performance with large capacity (up to ∼ 520 mAhg⁻¹), good rate capability (∼ 310 mAhg⁻¹ at 1,000 mAg⁻¹) and impressive cycling stability, superior to most competitors.

     

Quantum-confined ion superfluid in nerve signal transmission

We propose a process of quantum-confined ion superfluid (QISF), which is enthalpy-driven confined ordered fluid, to explain the transmission of nerve signals. The ultrafast Na⁺ and K⁺ ions transportation through all sodium-potassium pump nanochannels simultaneously in the membrane is without energy loss, and leads to QISF wave along the neuronal axon, which acts as an information medium in the ultrafast nerve signal transmission. The QISF process will not only provide a new view point for a reasonable explanation of ultrafast signal transmission in the nerves and brain, but also challenge the theory of matter wave for ions, molecules and particles.

     

Revealing the effect of anion-tuning in bimetallic chalcogenides on electrocatalytic overall water splitting

Enhancing electrocatalytic water splitting performance by modulating the intrinsic electronic structure is of great importance. Here, porous bimetallic oxide and chalcogenide nanosheets grown on carbon paper denoted as NiCo₂X₄/CP (X = O, S, and Se) are prepared to demonstrate how the anion components affect the electronic structures and thereby disclose the correlation between their intermediates interaction and catalytic activities. The experimental characterization and theoretical calculation demonstrate that Se and S substitution can promote the ratio of Co³⁺/Co²⁺ and thereby modulate the electronic structure accompanied with the upshift of d band centers, which not only enhance the inner conductivity but also regulate the interaction between the catalyst surface and intermediates, especially for the adsorption of absorbed H and hydroperoxy intermediates towards respective hydrogen evolution reaction (HER) and oxygen evolution reaction (OER). As a result, a full alkaline electrolyzer using NiCo₂Se₄/CP and NiCo₂S₄/CP as cathode and anode delivers a low voltage of 1.51 V at 10 mA·cm⁻², which is comparable even superior to most transition metal-based electrolyzers.

     

Synthesis of surface controlled nickel/palladium hydride nanodendrites with high performance in benzyl alcohol oxidation

Benzaldehyde byproduct is an imperative intermediate in the production of fine chemicals and additives. Tuning selectivity to benzaldehyde is therefore critical in alcohol oxidation reactions at the industrial level. Herein, we report a simple but innovative method for the synthesis of palladium hydride and nickel palladium hydride nanodendrites with controllable morphology, high stability, and excellent catalytic activity. The synthesized dendrites can maintain the palladium hydride phase even after their use in the chosen catalytic reaction. Remarkably, the high surface area morphology and unique interaction between nickel-rich surface and palladium hydride (β-phase) of these nanodendrites are translated in an enhanced catalytic activity for benzyl alcohol oxidation reaction. Our Ni/PdH_0.43 nanodendrites demonstrated a high selectivity towards benzaldehyde of about 92.0% with a conversion rate of 95.4%, showing higher catalytic selectivity than their PdH_0.43 counterparts and commercial Pd/C. The present study opens the door for further exploration of metal/metal-hydride nanostructures as next-generation catalytic materials.

     

Reproducible large-scale synthesis of surface silanized nanoparticles as an enabling nanoproteomics platform: Enrichment of the human heart phosphoproteome

A reproducible synthetic strategy was developed for facile large-scale (200 mg) synthesis of surface silanized magnetite (Fe₃O₄) nanoparticles (NPs) for biological applications. After further coupling a phosphate-specific affinity ligand, these functionalized magnetic NPs were used for the highly specific enrichment of phosphoproteins from a complex biological mixture. Moreover, correlating the surface silane density of the silanized magnetite NPs to their resultant enrichment performance established a simple and reliable quality assurance control to ensure reproducible synthesis of these NPs routinely in large scale and optimal phosphoprotein enrichment performance from batch-to-batch. Furthermore, by successful exploitation of a top-down phosphoproteomics strategy that integrates this high throughput nanoproteomics platform with online liquid chromatography (LC) and tandem mass spectrometry (MS/MS), we were able to specifically enrich, identify, and characterize endogenous phosphoproteins from highly complex human cardiac tissue homogenate. This nanoproteomics platform possesses a unique combination of scalability, specificity, reproducibility, and efficiency for the capture and enrichment of low abundance proteins in general, thereby enabling downstream proteomics applications.

     

Red/orange dual-emissive carbon dots for pH sensing and cell imaging

The dual-emissive N, S co-doped carbon dots (N, S-CDs) with a long emission wavelength were synthesized via solvothermal method. The N, S-CDs possess relatively high photoluminescence (PL) quantum yield (QY) (35.7%) towards near-infrared fluorescent peak up to 648 nm. With the advanced characterization techniques including X-ray photoelectron spectroscopy (XPS), Fourier transform infrared spectroscopy (FTIR), etc. It is found that the doped N, S elements play an important role in the formation of high QY CDs. The N, S-CDs exist distinct pH-sensitive feature with reversible fluorescence in a good linear relationship with pH values in the range of 1.0–13.0. What is more, N, S-CDs can be used as an ultrasensitive Ag⁺ probe sensor with the resolution up to 0.4 μM. This finding will expand the application of as prepared N, S-CDs in sensing and environmental fields.

     

Living electronics

Living electronics that converges the unique functioning modality of biological and electrical circuits has the potential to transform both fundamental biophysical/biochemical inquiries and translational biomedical/engineering applications. This article will review recent progress in overcoming the intrinsic physiochemical and signaling mismatches at biological/electronic interfaces, with specific focus on strategic approaches in forging the functional synergy through: (1) biohybrid electronics, where genetically encoded bio-machineries are hybridized with electronic transducers to facilitate the translation/interpretation of biologically derived signals; and (2) biosynthetic electronics, where biogenic electron pathways are designed and programmed to bridge the gap between internal biological and external electrical circuits. These efforts are reconstructing the way that artificial electronics communicate with living systems, and opening up new possibilities for many cross-disciplinary applications in biosynthesis, sensing, energy transduction, and hybrid information processing.