查找使用阿拉丁产品的科研文献

Morphology-dependent electrochemical performance of nitrogen-doped carbon dots@polyaniline hybrids for supercapacitors

Fei Xie,Mingchen Zhou,Guoyu Wang,Qiyang Wang,Manqing Yan,Hong Bi

Summary In this work, the binary N-CDs@PANI hybrids were fabricated by introducing zero-dimensional nitrogen-doped carbon dots (N-CDs) into reticulated PANI. Firstly, N-CDs were prepared by one-pot microwave method, and then, the N-CDs were introduced into in situ oxidative polymerization of aniline (ANI) monomer. The N-CDs with abundant functional groups and high electronic cloud density played a significant role in guiding the polyaniline-ordered growth into intriguing morphologies. Moreover, morphology-dependent electrochemical performances of N-CDs@PANI hybrids were investigated and N-CDs improve static interaction and enhance the special capacitances in the N-CDs@PANI hybrids. Especially, the specific capacitance of PC4 hybrid can reach 785 F g −1 , which exceed that of pure PANI (274 F g −1 ) at current density of 0.5 A g −1 according to three-electrode measurement. And the capacitance retention of the PC4 hybrid still keeps 70% after 2000 cycles of charge and discharge. The N-CDs@PANI hybrids can have potential applications in electrode materials, supercapacitors, nonlinear optics, and microwave absorption.

Highly efficient steam reforming of ethanol (SRE) over CeOx grown on the nano NixMgyO matrix: H2 production under a high GHSV condition

Xiang Luo,Yu Hong,Honglei Zhang,Kaiqi Shi,Gang Yang,Tao Wu

Summary Steam reforming of ethanol (SRE) over non-noble metal catalysts is normally conducted at high temperature (>600°C) to thermodynamically favour the catalytic process and carbon deposition mitigation. However, high temperature inhibits water-gas shift reaction (WGSR) and therefore restrains the yield of H 2 and leads to the formation of an excessive amount of CO. The modification of non-noble metal catalyst to enhance WGSR is an attractive alternative. In this study, CeO x was firstly loaded onto a nano-scaled Ni x Mg y O matrix and subsequently used as the catalyst for hydrogen production via SRE. Morphology of the catalyst materials was characterized by using a series of technologies, while H 2 -temperature programmed reduction (H 2 -TPR), CO-temperature programmed deposition (CO-TPD), and X-ray photoelectron spectroscopy (XPS), were employed to study the surface nickel, ceria clusters, and their interactions. The catalytic activity and durability of the catalyst were studied in the temperature region of 500°C to 800°C. The CeO x -coated nano Ni x Mg y O matrix exhibited an outstanding hydrogen yield of 4.82 mol/mol ethanol under a high gas hourly space velocity (GHSV) of 200 000 hour −1 . It is found that the unique Ni 0 -CeO x structure facilitates the adsorption of CO on the surface and therefore promotes the effective hydrogen production via WGSR. Moreover, this modified Ni x Mg y O matrix was found to be a more robust and anticoking nanocatalyst because of reversible switch between Ce 4+ and Ce 3+ .

Electrocatalytic performance of TiO2 with different phase state towards V2+/V3+ reaction for vanadium redox flow battery

Dixuan Cheng,Gang Cheng,Zhangxing He,Lei Dai,Ling Wang

Summary In this paper, titanium dioxide (TiO 2 ) nanoparticles were employed as catalysts towards V 2+ /V 3+ redox couple of vanadium redox flow battery (VRFB). The effect of TiO 2 phase on the electrocatalytic performance for negative couple was systematically investigated. The electrochemical properties of TiO 2 with different phase were assessed via cyclic voltammetry and electrochemical impedance spectroscopy by using AB as conductive agent. Obtained from the results, anatase TiO 2 (α-TiO 2 ) exhibits superior electrocatalytic activity to rutile TiO 2 (γ-TiO 2 ). The VRFB cell performs well at discharge capacity, voltage efficiency, and energy efficiency by employing α-TiO 2 -modified negative electrode with current density varying between 50 and 100 mA cm −2 . The discharge capacity of α-TiO 2 -modified cell with vanadium ion concentration of 1.6 M comes up to 113.5 mA h at 100 mA cm −2 current density, which is increased by 39.1 mA h after modification for negative electrode. Moreover, the corresponding energy efficiency increases by 7.5% after modification of α-TiO 2 . Experimental results show that TiO 2 is an ideal catalyst for VRFB. Moreover, α-TiO 2 demonstrates superior electrocatalytic performance to γ-TiO 2 towards V 2+ /V 3+ reaction.

A steel slag–derived Boudouard reaction catalyst for improved performance of direct carbon solid oxide fuel cells

Yong Jiao,Chongyang Wang,Liqin Zhang,Wenting An,Na Zhou,Guangming Yang,Wei Wang,Wei Zhou,Si-Dian Li

Summary Solid oxide fuel cells (SOFCs) can directly utilize solid carbon as fuel by integrating with the reverse Boudouard reaction in the anode chamber. Efficiency of the Boudouard gasification of solid carbon fuel is one of the crucial factors influencing the performance of direct carbon SOFCs (DC-SOFCs). In this paper, a novel Boudouard reaction catalyst derived from steel slag was first introduced into DC-SOFCs for improving the electrochemical performance. The catalytic activity of the steel slag was activated using the molten alkali method to decompose the inert mineral phases of the raw material. The steel slag–derived catalyst was loaded on the activated charcoal by a wet ball milling method. This kind of catalyst can match up to the readily available solid carbon fuels in cost. Promoted by this highly active Boudouard reaction catalyst, the initial Boudouard gasification temperature of the carbon fuel decreased by 99°C, and the producing rate of carbon monoxide doubled. Furthermore, the power outputs of the fuel cells increased from 91 to 159 mW cm −2 , and the fuel utilization increased from 17.10% to 46.43% at 825°C. This study demonstrates that the steel slag–derived catalyst is a promising material for the performance improvement of DC-SOFCs and may make a valuable contribution to their commercial application.

A high-performance CeO2@Pt-Beta yolk-shell catalyst used in low-temperature ethanol steam reforming for high-purity hydrogen production

Rong Dai,Ziliang Zheng,Chenshuai Lian,Xing Li,Xu Wu,Xia An,Xianmei Xie

Summary A novel Pt-based Beta encapsulated CeO 2 yolk-shell catalyst was successfully synthesized via a RF layer in the synthetic process. The CeO 2 @Pt-Beta catalyst showed high catalytic activity and stability toward the LT-ESR with respect to the reference Pt-Beta, CeO 2 -Pt-Beta, which benefited from the special yolk-shell structure and the synergistic effect between the CeO 2 movable core and Pt metal. The confinement effect of the yolk-shell architecture contributed to the high dispersion of Pt nanoparticles as well as to the accumulation of reactant molecules in the enclosed void space, which ensured the reactants reacted with CeO 2 and Pt to achieve a complete reaction.

Syntheses, Structures, Physical Properties, and Electronic Structures of Ba2MLnTe5 (M = Ga and Ln = Sm, Gd, Dy, Er, Y; M = In and Ln = Ce, Nd, Sm, Gd, Dy, Er, Y)

Wenlong Yin,Wendong Wang,Lei Bai,Kai Feng,Youguo Shi,Wenyu Hao,Jiyong Yao,Yicheng Wu

The 12 new rare-earth tellurides Ba2MLnTe5 (M = Ga and Ln = Sm, Gd, Dy, Er, Y; M = In and Ln = Ce, Nd, Sm, Gd, Dy, Er, Y) have been synthesized by solid-state reactions. The two compounds Ba2GaLnTe5 (Ln = Sm, Gd) are isostructural and crystallize in the centrosymmetric space group P1̅, while the other 10 compounds belong to another structure type in the noncentrosymmetric space group Cmc21. In both structure types, there are one-dimensional anionic 1∞[MLnTe5]4– chains built from LnTe6 octahedra and MTe4 (M = Ga, In) tetrahedra, but the connectivity between the LnTe6 octahedra and MTe4 tetrahedra is different for the two structure types. On the basis of the diffuse-reflectance spectra, the band gaps are around 1.1–1.3 eV for these compounds. The Ba2MLnTe5 (M = Ga and Ln = Gd, Dy; M = In and Ln = Gd, Dy, Er) compounds are paramagnetic and obey the Curie–Weiss law, while the magnetic susceptibility of Ba2InSmTe5 deviates from the Curie–Weiss law. In addition, electronic structure calculation on Ba2MYTe5 (M = Ga, In) indicates that they are both direct-gap semiconductors with large nonlinear-optical coefficients.

In vitro and in vivo assay of the ER lipid scramblase TMEM41B

Lingzhi Wu,Lu Liu,Bolin Xu,Dong Huang,Xiao-Wei Chen

Summary Amphipathic phospholipids translocated by scramblases play a central role in facilitating lipid movement across the membrane bilayer, especially at the endoplasmic reticulum (ER) membranes. Here, we present a protocol for assessing the activity of the ER-localized lipid scramblase TMEM41B. We detail an in vitro fluorescent liposome-based phospholipid scrambling assay and in vivo metabolic labeling in living cells using alkyne-choline. The scramblase activity of other VTT (VMP1, TMEM41, and Tvp38) domain-containing proteins, such as TMEM41A and VMP1, can be assayed. For complete details on the use and execution of this protocol, please refer to Huang et al. (2021) .

Nanoplate-Assembled Yb/Er-BiOBr Microspheres for Durable Self-Cleaning Photocatalytic Coatings

Yan Xiangyang,Li Ningning,Li Maoyi,Fan Kaixuan,Xia Huiyun

This study addresses the efficient and safe purification of low-concentration atmospheric NO. A Yb/Er-codoped nanostructured BiOBr was synthesized via a solvothermal method, and a composite superhydrophobic coating (FSBE) was fabricated by a layer-by-layer spraying strategy using epoxy resin, nano-SiO 2 , and perfluoroalkyltrimethoxysilane, achieving integrated high photocatalytic activity and excellent micronano-structured superhydrophobicity. The Yb/Er codoping successfully modulates the original layered BiOBr into spherical hollow microspheres assembled from interconnected nanoplates with an optimal Yb/Er ratio of 10:1. This modification enlarges the specific surface area by approximately 7 times, broadens the light response range, and effectively restrains the recombination of photogenerated carriers. The constructed FSBE coating possesses a micronano rough surface with water and ethylene glycol contact angles above 150 ° , demonstrating superior self-cleaning performance. Under visible light and full-spectrum irradiation, the FSBE coating delivers NO degradation efficiencies of 62.0 and 78.4%, which are 2.85-fold and 1.5-fold higher than those of pure BiOBr, respectively, while efficiently suppressing NO 2 accumulation. The coating maintains a photocatalytic efficiency of 65.8% after five cycling tests and exhibits excellent mechanical abrasion resistance and chemical stability. The synergistic effect between the superhydrophobic self-cleaning structure and nanoscale rare-earth-doping-enhanced photocatalysis accounts for its durable NO purification capability. This work provides an insight into the design of high-performance and long-lived photocatalytic nanocoatings for atmospheric environmental remediation.

ER-tethering directs TREX1 penetration of a BAF-dependent barrier at micronuclei

Yanyang Chen,Roshan Xavier Norman,Eléonore Toufektchan,Xiaohan Luan,Abraham Shim,Hannah Rosenberg,Marton Tibor Kovacs,Ashley Nichols,James Hickling,Paolo Cifani,Alex Kentsis,Wen Zhou,John Maciejowski

Micronuclei are membrane-encapsulated nuclear aberrations that form following chromosome segregation errors. Micronuclear membrane collapse permits access of the pattern recognition receptor cGAS and its antagonist, the TREX1 exonuclease. TREX1 endoplasmic reticulum tethering is essential for invasion into ruptured micronuclei, but the mechanisms underlying this dependency are unknown. Here, we identify BAF as a key regulator of TREX1 activity at micronuclei. BAF accumulates at micronuclei following membrane collapse and augments TREX1 recruitment via interactions with LEM-domain proteins. Despite delayed entry, TREX1 exhibits enhanced micronuclear DNA degradation and independence from ER-tethering in BAF-deficient cells. Recombinant BAF inhibits TREX1-mediated DNA degradation in vitro via DNA-binding. BAF similarly outcompetes cGAS for micronuclear DNA and limits cGAS-dependent immune signaling. These findings reveal a BAF-dependent protective barrier to the diffusive entry of DNA-binding proteins into ruptured micronuclei that explains TREX1 ER-tethering requirements for suppressing innate immune responses in chromosomally unstable cells.

Internal OH− defect-induced upconversion quenching in β-NaLuF4:Yb,Er microcrystals

Yue Wang,Yaomin Lei,Wuqin Chen,Ruian Yang,Xinyang Gu,Gaofeng Pan,Xuesong Zhai,Jinshan Wang

Luminescence quenching effect of lanthanide-doped upconversion materials occurs with high probability even in larger-sized particles, but their main quenching pathway remains controversial. In this work, we investigate the influence of the surfactant and pH value on the luminescence properties of β-NaLuF 4 :Yb,Er microcrystals. A convincing evidence can be provided by the combination of X-ray diffraction (XRD), inductively coupled plasma (ICP) spectrometer, and Eu 3+ structural probe measurements that the major quenching pathway comes from the fast energy migration from the excited lanthanides to nearby OH − defects in the crystal lattice rather than surface quenching effect. Even at OH − -rich reactant condition, the upconversion luminescence intensity becomes more efficient by reduced internal quenching effects. Our findings provide a new and fundamental understanding of severe luminescence quenching effect at microscale, thus guiding the design and preparation of highly efficient upconversion materials.

NiPS3 nanosheets for passive pulse generation in an Er-doped fiber laser

Jin Wang,Tao Wang,Xinyao Shi,Jian Wu,Yijun Xu,Xianguang Ding,Qiang Yu,Kai Zhang,Pu Zhou,Zongfu Jiang

With the rapidly increasing demands of industrial material processing, biomedical sensing, light detection, and high-speed communication, various novel two-dimensional (2D) materials have been synthesized and employed in ultrafast fiber laser generation due to their advantages of easy processing characteristics, desirable structures and excellent nonlinear optical properties. However, finding an efficient 2D material-based saturable absorber (SA) with the capacity of both high stability and excellent working property performance remains a challenge. Herein, high-quality NiPS3 crystals, from the metal phosphorus trichalcogenide (MPT3) family, were synthesized by a modified chemical vapor transport (CVT) method and a few-layer NiPS3 nanosheet SA was easily obtained using a direct liquid-phase exfoliation method. Different from other 2D materials, ultrathin NiPS3 nanosheets display a good stability. Moreover, a passively Q-switched operation and dual-wavelength mode-locked pulse output were proposed based on a NiPS3-SA erbium-doped fiber (EDF) laser. In the passively Q-switched operation, the maximum peak power was 6.40 mW with a maximum pulse energy of 29.66 nJ. It is also worth noting that dual-wavelength pulse output was achieved in passively mode-locked pulse generation. These results not only supply other choices of SAs for pulse generation, but also provide guidance to extend other possible applications of the MPT3 family for nonlinear optics.

Er-doped silicate fiber amplifiers in the L-band with flat gain

Yan Sun,Xin Wang,Qiubai Yang,Yafei Wang,Fan Wang,Lili Hu,Lili Hu,Lili Hu,Chunlei Yu,Chunlei Yu,Meisong Liao,Shubin Chen