Latest ArticlesPotassium ion batteries (PIBs) have been regarded as promising alternatives to lithium ion batteries (LIBs) on account of their abundant resource and low cost in large scale energy storage applications. However, it still remains great challenges to explore suitable electrode materials that can reversibly accommodate large size of potassium ions. Here, we construct oxygen-deficient V2O3 nanoparticles encapsulated in amorphous carbon shell (Od-V2O3@C) as anode materials for PIBs by subtly combining the strategies of morphology and deficiency engineering. The MOF derived nanostructure along with uniform carbon coating layer can not only enables fast K+ migration and charge transfer kinetics, but also accommodate volume change and maintain structural stability. Besides, the introduction of oxygen deficiency intrinsically tunes the electronic structure of materials according to DFT calculation, and thus lead to improved electrochemical performance. When utilized as anode for PIBs, Od-V2O3@C electrode exhibits superior rate capability (reversible capacities of 262.8, 227.8, 201.5, 179.8, 156.9 mAh/g at 100, 200, 500, 1000 and 2000 mA/g, respectively), and ultralong cycle life (127.4 mAh/g after 1000 cycles at 2 A/g). This study demonstrates a feasible way to realize high performance PIBs through morphology and deficiency engineering.
In this study, we proposed a novel method to investigate the advanced oxidation process of neonicotinoids (NNIs) from the perspective of concomitant chemiluminescence (CL) reaction. It was found that in the presence of cobalt ions with cyanoimino NNIs, acetamiprid (ACE) and thiacloprid (THI), could promote peroxymonosulfate and Ru(bpy)32+ to produce strong CL, but no CL occurred with nitro-involved NNIs as alternatives. Experimental dada from UV absorption spectra and chemiluminescence spectra suggested that new cyclic compounds might be formed during the reaction. Based on the results of free radical scavenging experiment and mass spectra, a new degradation and reaction mechanism of cyanoimino-containing NNIs was proposed. ACE or THI were first attacked by SO4•− to form benzyl radicals, which in turn reacted with the carbon atoms of cyano group through electrophilic addition reaction in the formation of intramolecular ring. Then a redox reaction between Ru(bpy)33+ and imino group immediately took place with CL emission (610 nm). The new mechanistic knowledge would be meaningful for other contaminants for their interactions with PMS.
The exploration of novel photo/thermal-responsive nonvolatile memorizers will be beneficial for energy-saving memories. Herein, new <110> -oriented perovskites using single template melamine, i.e., [(MLAI-H2)(PbX4)] (X = Br (α-1), Cl (α-2), MLAI = melamine) have been prepared and their structures upon irradiation of visible light have been investigated. They have been fabricated as nonvolatile memory devices with structures of ITO/[(MLAI-H2)(PbX4)]/PMMA/Ag (device-1: X = Br, device-2: X = Cl), which can exhibit unique visible light-triggered binary nonvolatile memory performances. Interestingly, the silent or working status can be monitored by visible chromisms. Furthermore, the light-triggered binary resistive switching mechanisms of these ITO/[(MLAI-H2)(PbX4)]/PMMA/Ag memory devices have been clarified in terms of EPR, fluorescence, and single-crystal structural analysis. The presence of light-activated traps in <110> -oriented [(MLAI-H2)(PbX4)] perovskites are dominated in the appearance of light-triggered resistive switching behaviors, based on which the inverted internal electrical fields can be established. According to the structural analysis, the more distorted PbX6 octahedra, higher corrugated <110> -oriented perovskite sheets, and more condensed organic-inorganic packing in Br-containing perovskite are beneficial for the stabilization of light-activated traps, which lead to the better resistive switching behavior of device-1. This work can pave a new avenue for the establishment of novel energy-saving nonvolatile memorizers used in aerospace or military industries.
The on-purpose direct propane dehydrogenation (PDH) has received extensive attention to meet the ever-increasing demand of propylene. In this work, by means of density functional theory (DFT) calculations, we systematically studied the intrinsic coordinating effect of Fe single-atom catalysts in PDH. Interestingly, the N and P dual-coordinated single Fe (Fe-N3P-C) significantly outperform the Fe-N4C site in catalysis and exhibit desired activity and selectivity at industrial PDH temperatures. The mechanistic origin of different performance on Fe-N3P-C and Fe-N4C has been ascribed to the geometric effect. To be specific, the in-plane configuration of Fe-N4 site exhibits low H affinity, which results in poor activity in CH bond activations. By contrast, the out-of-plane structure of Fe-N3P-C site exhibits moderate H affinity, which not only promote the CH bond scission but also offer a platform for obtaining appropriate H diffusion rate which ensures the high selectivity of propylene and the regeneration of catalysts. This work demonstrates promising applications of dual-coordinated single-atom catalysts for highly selective propane dehydrogenation.
A cadmium tetracyanoplatinate host clathrate, (MV)[Cd2{Pt(CN)4}3]⋅2(H2O) (1), including a methylviologen dication (MV2+) was synthesized, and the crystal structures, photochromic and photoluminescence properties were investigated. In 1, the alternatively parallel stacking between the MV2+ dications as electron acceptors in the channels and the electron donors [Pt1(CN)4]2– units in the host frameworks give a unique donor-acceptor (DA) system. Under UV irradiation, the electron transfer between MV2+ and [Pt(CN)4]2– ions generates MV·+ radicals with a photochromic behavior from pale-yellow to blue. This process occurs through single-crystal-to-single-crystal (SCSC) transformation and obvious structure variation of viologen cations is successfully observed. Moreover, the spectral overlap between the emission bands of 1 and the absorption around 623 nm for the MV·+ radicals leads to a modulation of the photoluminescence.
There is no clear consensus regarding how cells respond to hydrostatic pressure. This is largely attributable to the high heterogeneity among cell types and the diverse custom-made devices used in previous studies. The aim of this work was to develop a facile device that could mimic various pressure environments and then delineate the cellular response to pressure stimulus. The device described here achieved both stable and periodic pressurization without oxygen deprivation. The biological utility of the device was assessed using human umbilical vein endothelial cells. We found more stereoscopic nuclear morphology and re-distribution of lamin A/C under high hydrostatic pressure compared to control cells. Mass spectrometry-based proteomics analysis showed significant changes in mitochondria-related pathways. Western blot analysis confirmed that high hydrostatic pressure induced a tendency toward mitochondrial fusion. Increased mitochondrial activity was observed as well. In conclusion, this device can be readily applied in biological research and extend our understanding of cellular mechano-sensation and the associated changes in mitochondrial behaviors.
Perovskite quantum dots (PQDs) possess remarkable optical properties, such as tunable photoluminescence (PL) emission spectra, narrow full width at half maximum (FWHM) and high PL quantum yield (QY), endowing the PQDs great application prospects. However, the inherent structural instability of PQDs has seriously hindered the application of PQDs in various photoelectric devices. In this work, a microfluidic electrospinning method was used to fabricate color-tunable fluorescent formamidinium lead halogen (FAPbX3, X = Cl, Br, I) PQDs/polymer core-shell nanofiber films. The core-shell spinning nanofiber not only supplies the interspace for the in-situ formation of PQDs, but also significantly reduces the permeability of moisture and oxygen in the air, which greatly improves the stability of PQDs. After adjusting the composition of precursors, the blue-emissive polystyrene (core) and polymethyl methacrylate (shell) coated FAPbCl3 QDs (abbreviated as PS/FAPbCl3/PMMA, hereinafter), green-emissive PS/FAPbBr3/PMMA and red-emissive PS/FAPbI3/PMMA nanofiber films were fabricated with the highest PL QY of 82.3%. Moreover, the PS/FAPbBr3/PMMA nanofiber film exhibits great PL stability under blue light irradiation, long-term storage in the air and water resistance test. Finally, the green- and red-emissive nanofiber films were directly applied as light conversion films to fabricate wide-color-gamut display with the color gamut of 125%, indicating their tremendous potentials in optoelectronic applications.
The electricity-driven water splitting acts as a promising pathway for renewable energy conversion and storage, yet anodic oxygen evolution reaction (OER) largely hinders its efficiency. Seeking the alternatives to OER exhibits the competitive advance to address this predicament. In this work, we show a more thermodynamically and kinetically favorable reaction, electrochemical oxidative dehydrogenation (EODH) of benzylamine to replace the conventional OER, catalyzed by a cobalt cyclotetraphosphate (Co2P4O12) nanorods catalyst grown on nickel foam. This anodic reaction lowers the electricity input of 317 mV toward the desired current density of 100 mA/cm2, together with a highly selective benzonitrile product of more than 97%. More specifically, when coupling it with cathodic hydrogen evolution reaction (HER), the proposed HER||benzylamine-EODH configuration only requires a cell voltage of 1.47 V@100 mA/cm2, exhibiting an energy-saving up to 17% relative to conventional water splitting, as well as the near unit selectivity toward cathodic H2 and anodic benzonitrile products.
Na-CO2 batteries have attracted extensive attention due to their high theoretical energy density (1125 Wh/kg), efficient utilization of CO2, and abundant sodium resources. However, they are trapped by the sluggish decomposition kinetic of discharge products (mainly Na2CO3) on cathode side during the charging process. Here we prepared a series of nano-composites composed of RuO2 nanoparticles in situ loaded on activated multi-walled carbon nanotubes (RuO2@a-MWCNTs) through hydrolyzing reaction followed by calcination method and used them as cathode catalysts to accelerate the decomposition of Na2CO3. Among all catalysts, the RuO2@a-MWCNTs with appropriate ratio of RuO2 (49.7 wt%) demonstrated best stability and rate performance in Na-CO2 batteries, benefiting from both high specific surface area (160.3 m2/g) and highly dispersed RuO2 with ultrafine nanostructures (~2 nm). At a limited capacity of 500 mAh/g, Na-CO2 batteries could afford the operation of over 120 cycles at 100 mA/g, and even at the current density to 500 mA/g, the charge voltage was still lower than 4.0 V after 40 cycles. Further theoretical calculations proved that RuO2 was the catalytically active center and contributed to the decomposition of Na2CO3 by weakening the C=O bond. The synergetic functions of high specific surface (CNTs) and high catalytic activity (RuO2) will inspire more progress on metal-CO2 batteries.
Although many plasmonic nanosenosrs have been established for the detection of mercury(Ⅱ) (Hg2+), few of them is feasible for analyzing natural samples with very complex matrices because of insufficient method selectivity. To address this challenge, we propose an epitaxial and lattice-mismatch approach to the synthesis of a unique Au/Ag2S dimeric nanostructure, which consists of an Au segment with excellent plasmonic characteristics, and a highly stable Ag2S portion with minimum solubility product (Ksp(Ag2S) = 6.3 × 10−50). The detection relies on the chemical conversion of Ag2S to HgS when reacting with Hg2+, resulting in a red shift in the absorption band of the connecting Au NPs. The concurrent color changes of the solution from gray purple to dark green and finally to navy correlate well with Hg2+ concentration, thus enables UV–vis quantitation and a naked-eye readout of the Hg2+ concentration. This method exhibits superior selectivity towards Hg2+ over other interfering ions tested because Hg2+ is the only ion that can react with Ag2S to form HgS with even smaller solubility product (Ksp(HgS) = 4 × 10−53). The detection limit of this method is 1.21 µmol/L, calculated by the signal-to-noise of 3. The practicability of the method was verified by analyzing the Hg2+ in sewage water samples without sample pretreatment with satisfactory recoveries (93.1%-102.8%) and relative standard deviations (1.38%-2.89%). We believe this method holds great potential for on-the-spot detection of Hg2+ in environmental water samples with complex matrices.
No. 86 Xueyuan South Road, Haidian District, Beijing
010-62199257
qkjq@cast.org.cn
Copyright © 2025 China Association for Science and Technology. All rights reserved. For all open access content, the relevant licensing terms apply.
Sponsored by the Office of the Leading Group for Cybersecurity and Informatization of CAST, and supported by Science and Technology Review Publishing House
