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Small (Weinheim An Der Bergstrasse,... Jul 2024Lithium metal batteries are regarded as promising candidates for next-generation energy storage systems. However, their anodes are susceptible to interfacial instability...
Lithium metal batteries are regarded as promising candidates for next-generation energy storage systems. However, their anodes are susceptible to interfacial instability due to significant volume changes, which significantly impacts the cycle life of lithium metal batteries. Here, a rapid method for the fabrication of 3D-hosts with interface modified layers is reported. A simple infiltration and heating process enables the transformation of copper foam into Zn-BDC-modified copper foam within 1 min, rendering it suitable for use as a current collector for lithium metal anodes. The Zn-BDC nanosheets with high lithiophilicity are uniformly distributed on the surface of the current collector, facilitating the uniform deposition of lithium and reducing the volume change. Consequently, the half cell exhibits a remarkably low overpotential (26 mV) at a current-density of 4 mA cm and is cycled stably for 1000 h. Furthermore, it demonstrates a significant enhancement in performance in the LiFePO full cell. This study provides a crucial reference on the connection between the interfacial modification of the current collector and the lithium deposition behavior, which promotes the practicalization of lithium metal anodes.
PubMed: 38949398
DOI: 10.1002/smll.202403831 -
Small (Weinheim An Der Bergstrasse,... Jul 2024FeO is barely taken into account as an electrocatalyst for oxygen reduction reaction (ORR), an important reaction for metal-air batteries and fuel cells, due to its...
FeO is barely taken into account as an electrocatalyst for oxygen reduction reaction (ORR), an important reaction for metal-air batteries and fuel cells, due to its sluggish catalytic kinetics and poor electron conductivity. Herein, how strain engineering can be employed to regulate the local electronic structure of FeO for high ORR activity is reported. Compressively strained FeO shells with 2.0% shortened Fe─O bond are gained on the Fe/FeN cores as a result of lattice mismatch at the interface. A downshift of the d-band center occurs for compressed FeO, leading to weakened chemisorption energy of oxygenated intermediates, and lower reaction overpotential. The compressed FeO exhibits greatly enhanced electrocatalytic ORR activity with a kinetic current density of 27 times higher than that of pristine one at 0.80 V (vs reversible hydrogen electrode), as well as potential application in zinc-air batteries. The findings provide a new strategy for tuning electronic structures and improving the catalytic activity of other metal catalysts.
PubMed: 38949396
DOI: 10.1002/smll.202404065 -
Small (Weinheim An Der Bergstrasse,... Jul 2024The performance of perovskite solar cells has been continuously improving. However, humidity stability has become a key problem that hinders its promotion in the process...
An Impressive Open-Circuit Voltage of 1.223 V and High Humidity Stability of Perovskite Solar Cells with MgO Buffer Layer Deposited by Low-Temperature Atomic Layer Deposition.
The performance of perovskite solar cells has been continuously improving. However, humidity stability has become a key problem that hinders its promotion in the process of commercialization. A buffer layer deposited by atomic layer deposition is a very helpful method to solve this problem. In this work, MgO film is deposited between Spiro-OMeTAD and electrode by low-temperature atomic layer deposition at 80 °C, which resists the erosion of water vapor, inhibits the migration of electrode metal ions and the decomposition products of perovskite, then finally improves the stability of the device. At the same time, the MgO buffer layer can passivate the defects of porous Spiro, thus enhancing carrier transport efficiency and device performance. The Cs(FAPbI)(MAPbBr) perovskite device with a MgO buffer layer has displayed PCE of 22.74%, also with a high V of 1.223 V which is an excellent performance in devices with same perovskite component. Moreover, the device with a MgO buffer layer can maintain 80% of the initial efficiency after 7200 h of storage at 35% relative humidity under room temperature. This is a major achievement for humidity stability in the world, providing more ideas for further improving the stability of perovskite devices.
PubMed: 38949393
DOI: 10.1002/smll.202404199 -
Small (Weinheim An Der Bergstrasse,... Jul 2024Creating durable and efficient multifunctional electrocatalysts capable of high current densities at low applied potentials is crucial for widespread industrial use in...
Creating durable and efficient multifunctional electrocatalysts capable of high current densities at low applied potentials is crucial for widespread industrial use in hydrogen production. Herein, a Co-Ni-Fe-Cu-Mo (oxy)hydroxide electrocatalyst with abundant grain boundaries on nickel foam using a scalable coating method followed by chemical precipitation is synthesized. This technique efficiently organizes hierarchical Co-Ni-Fe-Cu-Mo (oxy)hydroxide nanoparticles within ultrafine crystalline regions (<4 nm), enriched with numerous grain boundaries, enhancing catalytic site density and facilitating charge and mass transfer. The resulting catalyst, structured into nanosheets enriched with grain boundaries, exhibits superior electrocatalytic activity. It achieves a reduced overpotential of 199 mV at 10 mA cm current density with a Tafel slope of 48.8 mV dec in a 1 m KOH solution, maintaining stability over 72 h. Advanced analytical techniques reveal that incorporating high-valency copper and molybdenum elements significantly enhances lattice oxygen activation, attributed to weakened metal-oxygen bonds facilitating the lattice oxygen mechanism (LOM). Synchrotron radiation studies confirm a synergistic interaction among constituent elements. Furthermore, the developed high-entropy electrode demonstrates exceptional long-term stability under high current density in alkaline environments, showcasing the effectiveness of high-entropy strategies in advancing electrocatalytic materials for energy-related applications.
PubMed: 38949312
DOI: 10.1002/smll.202401034 -
Journal of Visualized Experiments : JoVE Jun 2024Metal-organic frameworks (MOFs) are materials with potential applications in fields such as gas adsorption and separation, catalysis, and biomedicine. Attempts to...
Metal-organic frameworks (MOFs) are materials with potential applications in fields such as gas adsorption and separation, catalysis, and biomedicine. Attempts to enhance the utility of MOFs have involved the preparation of various composites, including polymer-grafted MOFs. By directly grafting polymers to the external surface of MOFs, issues of incompatibility between polymers and MOFs can be overcome. Polymer brushes grafted from the surface of MOFs can serve to stabilize the MOF while enabling particle assembly into self-assembled metal-organic framework monolayers (SAMMs) via polymer-polymer interactions. Control over the chemical composition and molecular weight of the grafted polymer can allow for tuning of the SAMM characteristics. In this work, instructions are provided on how to immobilize a chain transfer agent (CTA) onto the surface of the MOF UiO-66 (UiO = Universitetet i Oslo). The CTA serves as initiation sites for the growth of polymers. Once polymer chains are grown from the MOF surface, the formation of SAMMs is achieved through self-assembly at an air-water interface. The resulting SAMMs are characterized and shown to be freestanding by scanning electron microscopy imaging. The methods presented in this paper are expected to make the preparation of SAMMs more accessible to the research community and thereby expand their potential use as a MOF-polymer composite.
Topics: Polymers; Organometallic Compounds; Metal-Organic Frameworks; Phthalic Acids
PubMed: 38949297
DOI: 10.3791/66497 -
Nanoscale Jul 2024In carbon allotropes, a series of topological semi-metals have been predicted, but both novel electronic properties and mechanical characteristics, , a negative...
In carbon allotropes, a series of topological semi-metals have been predicted, but both novel electronic properties and mechanical characteristics, , a negative Poisson's ratio (NPR), are rarely discovered in the same sp type system. Here, a new three-dimensional carbon network, named WZGN, constructed from distorted one-dimensional zigzag graphene nanoribbons is proposed. The stability of the system is fully ensured by the phonon dispersion, AIMD simulation, and binding energy calculations. Besides, it is found that the system holds both topologically protected nodal line semi-metal properties together with an NPR property. Especially, the value of the NPR can exceed -0.36 when 21% uniaxial tensile strain along the '-direction is applied. Our findings point out that nodal line semi-metals can be compatible with intrinsic NPR properties in a wide strain range in carbon systems with sp hybridization, suggesting possible applications in mechanical and electronics fields.
PubMed: 38949270
DOI: 10.1039/d4nr01298d -
Dalton Transactions (Cambridge, England... Jul 2024A novel lysosome-targeted photosensitizer/photoredox catalyst based on cyclometalated Ir(III) complex IrL has been designed and synthesized, which exhibited excellent...
A novel lysosome-targeted photosensitizer/photoredox catalyst based on cyclometalated Ir(III) complex IrL has been designed and synthesized, which exhibited excellent phosphorescence properties and the ability to generate single oxygen (O) and photocatalytically oxidize 1,4-dihydronicotinamide adenine dinucleotide (NADH) under light irradiation. Most importantly, the aforementioned activities are significantly enhanced due to protonation under acidic conditions, which makes them highly attractive in light-activated tumor therapy, especially for acidic lysosomes and tumor microenvironments. The photocytotoxicity of IrL and the mechanism of cell death have been investigated. Additionally, the tumor-killing ability of IrL under light irradiation was evaluated using a 4T1 tumor-bearing mouse model. This work provides a strategy for the development of lysosome-targeted photosensitizers/photoredox catalysts to overcome hypoxic tumors.
PubMed: 38949269
DOI: 10.1039/d4dt01345j -
Nanotechnology Jul 2024The emergence of piezoelectric nanogenerators presents a promising alternative to supply energy demands within the realms of portable and miniaturized devices. In this...
The emergence of piezoelectric nanogenerators presents a promising alternative to supply energy demands within the realms of portable and miniaturized devices. In this article, the role of 2D transition metal dichalcogenide (TMD) tungsten sulfide (WS2) and conductive rGO sheets as filler materials inside the polyvinylidene fluoride (PVDF) matrix on piezoelectric performances has been investigated extensively. The strong electrostatic interaction between C-F and C-H monomer bonds of PVDF interacted with the large surface area of the WS2 nanosheets, increasing the electroactive polar phases and resulting in enhanced ferroelectricity in the PVDF/WS2 nanocomposite. Further, the inclusion of rGO sheets in the PVDF/WS2 composite allows mobile charge carriers to move freely through the conductive network provided by the rGO basal planes, which improves the internal polarization of the PVDF/WS2/rGO nanocomposites and increases the electrical performance of the piezoelectric nanogenerators (PENGs). The PVDF/WS2/0.3rGO nanocomposite-based PENG exhibits maximum piezoresponses with ~8.1 times enhancements in the output power density than the bare PVDF-based PENG. The mechanism behind the enhanced piezoresponses in the PVDF/WS2/rGO nanocomposites has been discussed. .
PubMed: 38949268
DOI: 10.1088/1361-6528/ad5d69 -
Angewandte Chemie (International Ed. in... Jul 2024Aurothiomalate (AuTM) is an FDA-approved antiarthritic gold drug with unique anticancer properties. To enhance its anticancer activity, we prepared a bioconjugate with...
Aurothiomalate (AuTM) is an FDA-approved antiarthritic gold drug with unique anticancer properties. To enhance its anticancer activity, we prepared a bioconjugate with human apoferritin (HuHf) by attaching some AuTM moieties to surface protein residues. The reaction of apoferritin with excess AuTM yielded a single adduct, that was characterized by ESI MS and ICP-OES analysis, using three mutant ferritins and trypsinization experiments. The adduct contains ~3 gold atoms per ferritin subunit, arranged in a small cluster bound to Cys90 and Cys102. MD simulations provide a plausible structural model for the cluster. The adduct was evaluated for its pharmacological properties and was found to be significantly more cytotoxic than free AuTM against A2780 cancer cells mainly due to higher gold uptake. NMR-metabolomics showed that AuTM bound to HuHf and free AuTM induced qualitatively similar changes in treated cancer cells, indicating that the effects on cell metabolism are approximately the same, in agreement with independent biochemical experiments. In conclusion, we have demonstrated here that a molecularly precise bioconjugate formed between AuTM and HuHf exhibits anticancer properties far superior to the free drug, while retaining its key mechanistic features. Evidence is provided that human ferritin can serve as an excellent carrier for this metallodrug.
PubMed: 38949226
DOI: 10.1002/anie.202410791 -
Journal of the American Chemical Society Jul 2024Transition metal-catalyzed enantioselective hydroamination of 1,3-dienes provides a direct methodology for the construction of chiral allylamines. So far, all of the...
Transition metal-catalyzed enantioselective hydroamination of 1,3-dienes provides a direct methodology for the construction of chiral allylamines. So far, all of the reported examples used nucleophilic amines and proceeded with 3,4-regioselectivity. Herein, we describe the first example of nickel-catalyzed enantioselective 1,4-hydroamination of 1,3-dienes using trimethoxysilane and hydroxylamines with a structurally adaptable aromatic spiroketal based chiral diphosphine (SKP) as the ligand, affording a wide array of α-substituted chiral allylamines in high yields with excellent regio- and enantioselectivities. This operationally simple protocol demonstrated a broad substrate scope and excellent functional group compatibility, significantly expanding the chemical space for chiral allylamines. Experimental and DFT studies were performed to elucidate the mechanism and to rationalize the regio- and enantioselectivities of the reaction.
PubMed: 38949166
DOI: 10.1021/jacs.4c03854