A novel Pt/CN catalyst was synthesized by sodium borohydride treatment. The physical and chemical properties of Pt/CN catalyst were characterized by X-ray diffraction (XRD), brunner-emmet-teller ...(BET), transmission electron microscope (TEM) and High-resolution transmission electron microscopy (HRTEM). The characterized results showed that the catalyst has a high specific surface area, mesoporous structure and the mean size of Pt nanoparticles is 2.59 nm. Subsequently, the catalytic performance of Pt/CN catalyst for decline dehydrogenation was studied. Pt/CN catalyst exhibited excellent performance in decalin dehydrogenation with the conversion of decalin was 30.70%, and the selectivity of naphthalene was 90.86% at 200 ℃ for 150 minutes. When the reaction temperature increased to 210 ℃, the conversion of catalyst increased to 52.02%, and the selectivity of naphthalene reduced to 90.21%. The possible reason may be attributed to the difficulty in converting decalin to tetralin. This paper would provide a novel method for the synthesis of efficient dehydrogenation catalyst of decalin..
Pt nanoparticles supported on nitrogen doped carbon (Pt/CN) catalysts with different surface areas were obtained and characterized by transmission electron microscope （TEM） and brunner-emmet-teller ...（BET）. The characterized results showed that Pt nanoparticles dispersed uniformly on the support surface, and the surface area of the Pt/CN catalyst increased with the increase of annealing temperature. Subsequently, the catalytic performance of Pt/CN catalysts for methylcyclohexane dehydrogenation was studied. The activity of Pt/CN catalysts in methylcyclohexane dehydrogenation increased with the increase of the surface area, Pt/CN-1000 catalyst has the largest surface area and the highest catalytic activity, with the methylcyclohexane conversion of 99% and the TOF value of 424.78 h
-1
at 180 ℃ for 150 minutes.
Reclaiming kinetic energy from vibrating machines holds great promise for sustainable energy harvesting technologies. Nevertheless, the impulsive current induced by vibrations is incompatible with ...conventional energy storage devices. The energy‐management system necessitates novel designs of soft materials for lightweight, miniaturized, and integrated high‐frequency electrochemical devices. Here, this work develops a conductive hydrogel with an electro‐responsive polymeric network. The electro‐responsive breathing transition of the crosslinking points facilitates the expeditious formation of a localized electrolyte layer. This layer features an exceedingly high local charge density, surpassing that of a saturated electrolyte solution by an order of magnitude, and thus enabling rapid charge transport under the influence of an applied voltage. The micro‐capacitor based on the gel exhibits record‐high capacitance of ≈2 mF cm−2 when the frequency of energy input reaches up to 104 Hz. This work also demonstrates a prototype battery charger that harvests energy from a running car engine. This study presents a feasible strategy for waste energy recycling using integrated electrochemical devices, opening a new avenue for ambient energy management.
Conductive hydrogel, engineered with a PEDOT:PSS network featuring dynamic crosslinking points, exhibits electro‐responsive behavior for efficient energy storage. The high‐density charge surfaces enable breathing transitions under voltage, offering superior frequency compatibility. The flexible energy harvester based on such hydrogel reclaims kinetic energy, suggesting topological‐structure engineering of hydrogels as a promising route for ambient energy management.
Efficient dehydrogenation of cyclohexane at low temperatures is of great importance in the field of liquid organic hydrogen carriers (LOHCs). In this paper, a series of Pt nanoparticles with a size ...distribution of 1.6–3.1 nm were loaded on nitrogen-doped carbon (Pt/CN) as the catalysts for cyclohexane dehydrogenation under low temperatures (180–210 °C). The effect of the Pt particle size on its catalytic performance was systematically explored. It is found that a volcanic trend exists between Pt particle size and its catalytic activity for cyclohexane dehydrogenation. The conversion of cyclohexane to benzene reaches up to 96.03% at 210 °C within 90 min using the Pt/CN catalyst with a Pt particle size of 1.9 nm. The corresponding activation energy of cyclohexane dehydrogenation is calculated to be as low as 36.2 kJ·mol–1 when compared with that using the other synthetic catalysts. By detailed characterizations of all Pt/CN catalysts, it is deduced that the Pt particle size effect on cyclohexane dehydrogenation can be attributed to the competition between the increased active sites and the covered active sites by products when decreasing the Pt particle size. This work provides not only a systematic study on the size effect of Pt particles but also a new way to design efficient and stable catalysts for cyclohexane dehydrogenation.
Transition metals can deliver high lithium storage capacity, but the reason behind this remains elusive. Herein, the origin of this anomalous phenomenon is uncovered by
magnetometry taking metallic ...Co as a model system. It is revealed that the lithium storage in metallic Co undergoes a two-stage mechanism involving a spin-polarized electron injection to the 3d orbital of Co and subsequent electron transfer to the surrounding solid electrolyte interphase (SEI) at lower potentials. These effects create space charge zones for fast lithium storage on the electrode interface and boundaries with capacitive behavior. Therefore, the transition metal anode can enhance common intercalation or pseudocapacitive electrodes at high capacity while showing superior stability to existing conversion-type or alloying anodes. These findings pave the way for not only understanding the unusual lithium storage behavior of transition metals but also for engineering high-performance anodes with overall enhancement in capacity and long-term durability.
A novel synthetic approach based on the reaction between tetrabutyl titanate and normal fatty acids is proposed to fabricate hierarchical nanoporous TiO2(B) assemblies with tailored crystallites and ...architectures, which not only sheds new light on TiO2(B) crystallization, but also provides an effective solution for rational design of complex TiO2(B) micro-/nanoarchitectures for desired applications.
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In comparison to the common anatase, rutile and brookite phases, the bronze phase TiO2 (TiO2(B)) is rarely prepared, and obtaining unique TiO2(B) structures, especially those with complex configurations remains a great challenge. This work presents a completely new synthetic approach for fabricating hierarchical nanoporous TiO2(B) assemblies with tailored crystallites and architectures via the reaction between tetrabutyl titanate and normal fatty acids. Three different kinds of normal fatty acids, i.e., pentanoic acid, hexanoic acid, and nonanoic acid were utilized as the sole solvent. After a simple solvothermal treatment, nanoporous TiO2(B) microspheres constructed by 001-elongated ultrathin nanorods, randomly aggregated ultrafine nanocrystals, and crystallographically oriented nanocrystals were successfully produced separately. Further investigation revealed that the morphology of the hierarchical assemblies could be modified by using foreign substrates to adjust the growth dynamics of TiO2(B) crystals. As a good illustration, by introducing graphene nanosheets into the tetrabutyl titanate-pentanoic acid system, nanosized 001-elongated-ultrathin-nanorod-constructed nanoporous TiO2(B) assemblies were obtained, which exhibited superior performance as an anode in Li-ion batteries. This work can not only shed new light on TiO2(B) crystallization, but also provide an effective solution for the rational design of complex TiO2(B) micro-/nanoarchitectures for desired applications.
The oxygen evolution reaction (OER) and oxygen reduction reaction (ORR) are considered to be cornerstones of many energy conversion and storage technologies. It is difficult studying high-performance ...nonprecious materials as cost-effective bifunctional electrocatalysts for both the OER and ORR in future practical applications. In this study, NiCo2S4 hollow spheres (NiCo2S4 HSs) were fabricated via an effective and facile one-pot “green” approach in an N,N-dimethylformamide–ethylene glycol binary solution. The obtained NiCo2S4 HSs had a high specific surface area as well as numerous active sites and showed a remarkable catalytic performance and durability toward both the OER and ORR in an alkaline electrolyte. For the ORR, NiCo2S4 HSs exhibited a positive half-wave potential of 0.80 V and demonstrated outstanding stability and enhanced methanol tolerance. For the OER, NiCo2S4 HSs presented a low overpotential (400 mV) at a current density of 10 mA cm–2, small Tafel slope, and excellent stability in 0.1 M KOH. Moreover, regarding the overall electrocatalytic activity, the potential difference of NiCo2S4 HSs was 0.83 V, surpassing that of NiCo2S4 nanoparticles, binary counterparts (CoS, NiS), and most highly active bifunctional catalysts described in the literature. The superior catalytic performance of NiCo2S4 HSs is mainly ascribed to its unique hollow structure, which increases molecular diffusion and adsorption, as well as the synergistic effect of Ni and Co, which offers richer redox reaction sites. Importantly, this strategy may facilitate the design and preparation of excellent bifunctional nonprecious metal electrocatalysts in various domains.
Achieving high stability and excellent optical performance in complex environments is crucial for practical applications of magnetically responsive photonic crystals (MRPCs). It, however, remains a ...great challenge. This study demonstrates a polyphenol‐mediated strategy for synthesizing size‐controllable superparamagnetic magnetite (Fe3O4) colloid nanocrystal clusters (CNCs) that can be stably dispersed in various polar solvents to form MRPCs with brilliant structural colors for a long term. As tannic acid (TA) functions as a linker to robustly bind polyvinylpyrrolidone (PVP) chains to Fe3O4 surfaces, the MRPCs can maintain nearly constant diffraction wavelength and high reflectance for up to 4 years. The strong coordination between TA and Fe3+ inhibits crystal growth, ensuring the small primary crystal size and superparamagnetism of Fe3O4@TA‐PVP CNCs. Partial oxidation of TA accelerates the crystal nucleation and growth, reducing the overall CNC particle size, which can be utilized for controlling the particle size. Additionally, enhancing the dissolution of PVP before the solvothermal reaction improves the size monodispersity of the products, making the as‐constructed MRPCs ideal for practical applications in color display, sensors, anti‐counterfeiting, and camouflage. The Fe3O4@TA‐PVP CNCs with high stability and versatility for surface‐functionalization are also promising for magnetic resonance imaging, targeting drug delivery, recyclable catalysis, and magnetic nanomotors.
A polyphenol‐mediated strategy is developed for the size‐controllable synthesis of monodisperse superparamagnetic magnetite nanoclusters, which can be used to construct highly stable magnetically responsive photonic crystals with diffraction wavelength and intensity nearly constant for up to 4 years due to the robust polyvinylpyrrolidone binding on Fe3O4 nanocrystal surface via tannic acid bridges.
The synthesis, structural characterization, exfoliation, and photophysical studies of two-dimensional (2-D) lanthanide phosphonates, named
Ln(
m
-pbc)
; Ln(
m
-Hpbc)(
m
-H
2
pbc)(H
2
O) (Ln = Eu, Tb;
...m
-pbc = 3-phosphonobenzoic acid) based on the phosphonocarboxylate ligand, are reported. These compounds are neutral polymeric 2D layered structures with pendent uncoordinated carboxylic groups between layers. The nanosheets were obtained by a top-down strategy involving sonication-assisted solution exfoliation and characterized by atomic force microscopy and transmission electron microscropy, showing lateral dimensions from nano- to micro-meter scales, and thicknesses down to several layers. The photoluminescence studies demonstrate that the
m
-pbc ligand acts as an efficient antenna toward Eu and Tb(
iii
) ions. The emission intensities of dimetallic compounds are clearly enhanced after incorporation of Y(
iii
) ions due to the dilution effect.
Ln(
m
-pbc)s
were then applied for labelling latent fingerprints. It is worth noting that the reaction between active carboxylic groups and fingerprint residues benefits the labelling, showing efficient imaging for fingerprints on all kinds of material surfaces.
Nanosheets of 2-D lanthanide phosphonocarboxylate frameworks are exfoliated and the pendent carboxyl groups react with intrinsic amino groups in the ridges to form covalent bonds for strong labelling of fingerprints.
The Mongolian medicine Eerdun Wurile is a commonly used Mongolian in folk medicine used to treat cerebral nervous system diseases such as cerebral hemorrhage, cerebral thrombosis, nerve injury and ...cognitive function, cardiovascular diseases such as hypertension and coronary heart disease. Eerdun wurile may effect anti-postoperative cognitive function.
To investigate the molecular mechanism of the Mongolian medicine Eerdun Wurile Basic Formula (EWB) in improving postoperative cognitive dysfunction (POCD) based on Network pharmacology, and to confirm involvement of the SIRT1/p53 signal pathway, one of the key signal pathways, by using the POCD mouse model.
Obtain compounds and disease-related targets through TCMSP, TCMID, PubChem, PharmMapper platforms, GeneCards, and OMIM databases, and screen intersection genes; Use Cytoscape software to build a “drug-ingredient-disease-target” network, and the STRING platform for protein interaction analysis.; R software was used to analyze the function of gene ontology (GO) and the Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment.; AutoDock Vina software for active components and core targets to Perform molecular docking. The POCD mouse model was prepared by intracerebroventricular injection of lipopolysaccharide (LPS), and the morphological changes of hippocampal tissue were observed by hematoxylin-eosin (HE) staining, Western blot, immunofluorescence and TUNEL were used to verify the results of network pharmacological enrichment analysis.
There were 110 potential targets for improving POCD by EWB, 117 items were enriched by GO, and 113 pathways were enriched by KEGG, among which the SIRT1/p53 signaling pathway was related to the occurrence of POCD. Quercetin, kaempferol, vestitol, β-sitosterol and 7-methoxy-2-methyl isoflavone in EWB can form stable conformations with low binding energy with core target proteins IL-6, CASP3, VEGFA, EGFR and ESR1. Animal experiments showed that compared with the POCD model group, the EWB group could significantly improve the apoptosis in the hippocampus of the mice, and significantly down-regulate the expression of Acetyl-p53 protein (P < 0.05).
EWB can improve POCD with the characteristics of multi-component, multi-target, and multi-pathway synergistic effects. Studies have confirmed that EWB can improve the occurrence of POCD by regulating the expression of genes related to the SIRT1/p53 signal pathway, which provides a new target and basis for the treatment of POCD.
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•Eerdun Wurile has significant anti-inflammatory effects and efficacy in improving postoperative cognitive dysfunction.•Regulation of the SIRT1/p53 signaling pathway is one of the therapeutic mechanisms of Eerdun wurile in improving postoperative cognitive dysfunction.
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