Self-enhanced localized alkalinity at the encapsulated Cu catalyst for superb electrocatalytic nitrate/nitrite reduction to NH3 in neutral electrolyte.

The electrocatalytic nitrate/nitrite reduction reaction (eNOx-RR) to ammonia (NH3) is thermodynamically more favorable than the eye-catching nitrogen (N2) electroreduction. To date, the high eNOx-RR-to-NH3 activity is limited to strong alkaline electrolytes but cannot be achieved in economic and sustainable neutral/near-neutral electrolytes. Here, we construct a copper (Cu) catalyst encapsulated inside the hydrophilic hierarchical nitrogen-doped carbon nanocages (Cu@hNCNC). During eNOx-RR, the hNCNC shell hinders the diffusion of generated OH- ions outward, thus creating a self-enhanced local high pH environment around the inside Cu nanoparticles. Consequently, the Cu@hNCNC catalyst exhibits an excellent eNOx-RR-to-NH3 activity in the neutral electrolyte, equivalent to the Cu catalyst immobilized on the outer surface of hNCNC (Cu/hNCNC) in strong alkaline electrolyte, with much better stability for the former. The optimal NH3 yield rate reaches 4.0 moles per hour per gram with a high Faradaic efficiency of 99.7%. The strong-alkalinity-free advantage facilitates the practicability of Cu@hNCNC catalyst as demonstrated in a coupled plasma-driven N2 oxidization with eNOx-RR-to-NH3.

Gas Imaging with Uncooled Thermal Imager.

Gas imaging has become one of the research hotspots in the field of gas detection due to its significant advantages, such as high efficiency, large range, and dynamic visualization. It is widely used in industries such as natural gas transportation, chemical, and electric power industries. With the development of infrared detector technology, uncooled thermal imagers are undergoing a developmental stage of technological advancement and widespread application. This article introduces a gas imaging principle and radiation transfer model, focusing on passive imaging technology and active imaging technology. Combined with the actual analysis, the application scenarios using uncooled thermal imaging cameras for gas imaging measurement are analyzed. Finally, the limitations and challenges of the development of gas imaging technology are analyzed.

Loss-free pulverization by confining copper oxide inside hierarchical nitrogen-doped carbon nanocages toward superb potassium-ion batteries.

Taking the advantages of hierarchical nitrogen-doped carbon nanocages (hNCNCs) with nanocavities for encapsulation and multiscale micro-meso-macropores/high conductivity for mass/electron synergistic transportation, a conversion-type CuO anode material is confined inside hNCNCs for potassium storage. The so-obtained yolk-shelled CuO@hNCNC hybrids have tunable CuO contents in the range of 11.7-63.7 wt%. The unique architecture leads to the loss-free pulverization of the active components during charge/discharge, which increases the surface-controlled charge storage, shortens the K+ solid diffusion lengths with an enlarged K+ diffusion coefficient, and meanwhile enhances the rate capability and durability. Consequently, the optimized CuO@hNCNC delivers a high specific capacity of 498 mA h g-1 at 0.1 A g-1 and 194 mA h g-1 at 10.0 A g-1 based on the total mass of CuO@hNCNC, and a long-term stability. The capacity based on the CuO active component reaches a record-high 522 mA h g-1 at 1.0 A g-1 after 2000 cycles, which is ca. 2.5 times the state-of-the-art value in the literature. The evolution of the cycling performance with CuO loading is well understood based on the loss-free pulverization. This study demonstrates a new strategy to turn the generally harmful pulverization of active components into a beneficial factor for K+ storage, which paves the way for exploring high-performance anodes for rechargeable batteries.

High-Dispersive Pd Nanoparticles on Hierarchical N-Doped Carbon Nanocages to Boost Electrochemical CO2 Reduction to Formate at Low Potential.

Electrochemical CO2 reduction reaction (CO2 RR) to value-added chemicals/fuels is an effective strategy to achieve the carbon neutral. Palladium is the only metal to selectively produce formate via CO2 RR at near-zero potentials. To reduce cost and improve activity, the high-dispersive Pd nanoparticles on hierarchical N-doped carbon nanocages (Pd/hNCNCs) are constructed by regulating pH in microwave-assisted ethylene glycol reduction. The optimal catalyst exhibits high formate Faradaic efficiency of >95% within -0.05-0.30 V and delivers an ultrahigh formate partial current density of 10.3 mA cm-2 at the low potential of -0.25 V. The high performance of Pd/hNCNCs is attributed to the small size of uniform Pd nanoparticles, the optimized intermediates adsorption/desorption on modified Pd by N-doped support, and the promoted mass/charge transfer kinetics arising from the hierarchical structure of hNCNCs. This study sheds light on the rational design of high-efficient electrocatalysts for advanced energy conversion.

The Composite-Template Method to Construct Hierarchical Carbon Nanocages for Supercapacitors with Ultrahigh Energy and Power Densities.

3D hierarchical carbon nanocages (hCNC) are becoming new platforms for advanced energy storage and conversion due to their unique structural characteristics, especially the combination of multiscale pore structure with high conductivity of sp2 carbon frameworks, which can promote the mass/charge synergetic transfer in various electrochemical processes. Herein, the MgO@ZnO composite-template method is developed to construct hCNC and nitrogen-doped hCNC (hNCNC), which integrates the advantages of the in situ MgO template method and ZnO self-sacrificing template method. The hierarchical MgO template provides the scaffold for depositing carbon nanocages, while the self-sacrificing ZnO template helps create abundant micropores while promoting the graphitization degree, so that the microstructures of the products are effectively regulated. The optimized hCNC and hNCNC have an increased specific surface area and conductivity, which can further boost the mass/charge synergetic transfer. As the electrode materials of supercapacitors, the optimal hCNC(hNCNC) exhibits a high specific capacitance of 281(348) F g-1 in KOH and 276(297) F g-1 in EMIMBF4 electrolytes at 1 A g-1 . The ultrahigh energy and power densities are realized, accompanied by a high-rate capability and long cycling stability. The record-high energy densities of 141.8-71.4 Wh kg-1 are achieved in EMIMBF4 at power densities of 10.0-250.4 kW kg-1 .

Analysis of the Stable Interphase Responsible for the Excellent Electrochemical Performance of Graphite Electrodes in Sodium-Ion Batteries.

Considerable efforts have been exerted to understand the formation and properties of the solid electrolyte interphase (SEI) in sodium ion batteries. However, the puzzling existence and role of SEI behind the huge volume changes of the graphite electrodes need to be answered. Herein, the reason of how ether-derived SEI maintains excellent reversibility despite the huge volume changes during cycling is unraveled. Theoretical simulations and Fourier-transform infrared spectroscopy demonstrate the formation mechanism of an SEI between the graphite anode and electrolyte. Furthermore, the high mechanical tolerance of the ether-derived SEI is confirmed in atomic force microscopy. A depth profile of X-ray photoelectron spectroscopy points to a multilayer structure of the ether-derived SEI. The outer layer comprises organics (sodium alkoxide), while the inorganics (Na2 CO3 , NaF) in interior region are mixed with some organics. Notably, the presence of organics ensures the adaptability of the SEI to the volume expansion of graphite during cycling, and the concentrated distribution of inorganics improves the Young's modulus (resistance to deformation). Therefore, the graphite anode exhibits high cycle stability (96.6% capacity retention ratio at 1 A g-1 over 860 cycles) and efficiency (≈99.5%).

PY13FSI-Infiltrated SBA-15 as Nonflammable and High Ion-Conductive Ionogel Electrolytes for Quasi-Solid-State Sodium-Ion Batteries.

Exploring electrolytes of high safety is essential to pave the practical route for sodium-ion batteries (SIBs) toward their important applications in large-scale energy storage and power supplies. In this regard, ionogel electrolytes (IEs) have been highlighted owing to their high ionic conductivity, prominent electrochemical and thermal stability, and, more crucially, high interfacial wettability. However, present studies lack an understanding of the interaction of IEs, which determines the ion desolvation and migration. In this article, IEs comprising an SBA-15 host, an ionic liquid, sodium salt, and poly(vinylidene fluoride)-hexafluoro propylene (PVDF-HFP) have been proposed by mechanical ball milling and roller pressing. The component ratio has been optimized based on the balance between ionic conductivity and self-supporting capability of IEs. The optimal IEs showed sufficiently high ionic conductivity (2.48 × 10-3 S cm-1 at 30 °C), wide electrochemical window (up to 4.8 V vs Na+/Na), and high Na+ transference number (0.37). Due to the presence of SBA-15 and an ionic liquid, the IEs exhibited much improved thermal resistance than that of the conventional organic liquid electrolytes (OLEs). Furthermore, Fourier transform infrared (FT-IR) spectroscopy revealed the hydrogen bonding interaction between silanols and the dissolved salts, not only anchoring anions for immobilization but also promoting the dissociation of sodium salts. After being matched with the Na3V2(PO4)3 (NVP) cathode and metallic Na anode, the SIBs presented a specific discharge capacity of up to 110.7 mA h g-1 initially at room temperature with 92% capacity retention after 300 cycles. The improved safety and electrochemical performance provided insights into rationally regulating IEs and their interactions with the prospect of strengthening their practical applications in SIBs.

Developing an Interpenetrated Porous and Ultrasuperior Hard-Carbon Anode via a Promising Molten-Salt Evaporation Method.

Hard carbon (HC) has become one of the prospective anode materials for sodium-ion batteries (SIBs), but its application suffers from the low electron conductivity and poor ion-diffusion kinetics. In this study, the melting and evaporation process of neutral salt was first introduced to produce nitrogen-rich interpenetrated porous HC (NIP-HC) as the anode for SIBs. Such a protocol allows for the first-demonstrated porous structure for HC materials with desired electronic conductivity and much improved rate performance than the conventional porous structure. As a result, high reversible capacity (358 mA h g-1) and enhanced rate property (239.8 mA h g-1 at 2 A g-1) are achieved with improved electrode kinetics and electron conductivity because of the accelerated charge transfer derived from the unique porosity and nitrogen heteroatom-doping. More interestingly, the increase of the surface area of NIP-HC does not lead to a decrease of the initial efficiency. At the same time, a high plateau capacity (172.8 mA h g-1) can be obtained below 0.1 V, which shows great potential for practical application in the full cells. As suggested by IG/ID from Raman tests, the degree of graphitization increases accompanied by the melting and evaporation process, which improves the electrical conductivity of the HC material as well. Furthermore, according to first-principle calculations, it is found that the nitrogen is conducive to increasing the electron density around the Fermi level, which intrinsically enhances the electrical conductivity and enriches active sites for sodium-ion storage. The result from this study has provided insights into producing interpenetrated porous HC by a simple and novel salt melting and evaporation process and enriched the methods of pore structure preparation.

Inhibition of Crystallization of Poly(ethylene oxide) by Ionic Liquid: Insight into Plasticizing Mechanism and Application for Solid-State Sodium Ion Batteries.

All-solid-state sodium ion batteries (ASIBs) possess enhanced safety and desired cycling life compared with conventional liquid sodium batteries, showing great potential in large-scale energy storage systems. Polymer electrolytes based on poly(ethylene oxide) (PEO) have been extensively studied for ASIBs due to superior flexibility and processability. However, PEO-based electrolyte without any modification can hardly meet the requirements of ASIBs at room temperature. In the past decade, unremitting efforts have been attached to inhibiting crystallization of PEO, especially via ionic liquid plasticizing. However, the plasticizing mechanism is not clear. Here we incorporated Pyr13FSI into PEO-NaClO4 electrolyte to investigate the plasticizing effect by infrared spectrum characterizations and DFT calculations. The results indicate that FSI- anions tend to adhere to the PEO backbone, generating enhanced coordination ability and more coordination sites. Solid-state sodium ion batteries using PEO-NaClO4-40 wt % Pyr13FSI as polymer electrolyte exhibit good cycling and rate performance. Insights into the plasticizing mechanism contribute to fabricating polymer electrolyte with high performance for ASIBs.

High-Capacity Interstitial Mn-Incorporated MnxFe3-xO4/Graphene Nanocomposite for Sodium-Ion Battery Anodes.

Sodium-ion batteries (SIBs) have attracted wide attention because of their prospects for grid-scale electrical regulation and cost effectiveness of sodium. In this regard, iron oxides (FeOx) are considered as one of the most promising anode candidates due to their high theoretical capacity and low cost. Unfortunately, the utilization of FeOx anodes suffers from sluggish reaction kinetics and significant lattice variation, causing insufficient rate performance and fast capacity degradation during the sodiation/desodiation process. In this study, Mn ions are incorporated through interstitial sites into a Fe3O4 lattice to form the Mn-incorporated Fe3O4/graphene (M-Fe3O4/G) composites through a facile hydrothermal method. Confirmed by XRD Rietveld refinement and the first-principles calculation, Mn occupation into the body structure can effectively condense the electron density around the Fermi level and thus contributes to the increased electrical conductivity and improved electrochemical properties. Accordingly, the M0.1Fe2.9O4/G composite demonstrates a high reversible capacity of 439.8 mA h g-1 at a current density of 100 mA g-1 over 200 cycles. Even at a high current density of 1 A g-1, the M-Fe3O4/G composites remain stable for over 1200 cycles, delivering a capacity of 210 mA h g-1. Coupled with a Na3V2(PO4)3-type cathode, the Mn-incorporated Fe3O4/G composites demonstrate good suitability in full SIBs (161.2 mA h g-1 at the current density of 1 A g-1 after 100 cycles). The regulation of Mn ions in the Fe3O4 lattice provides insights into the optimization of metal oxide anode candidates for their application in SIBs.

Carbon Nanofiber Elastically Confined Nanoflowers: A Highly Efficient Design for Molybdenum Disulfide-Based Flexible Anodes Toward Fast Sodium Storage.

Two-dimensional energy materials have been widely applied in advanced secondary batteries, among which molybdenum sulfide (MoS2) is attractive because of the potential for high capacity and good rate performance. The relatively low electronic conductivity and irreversible volume expansion of pure MoS2 still need to be improved. Here, a facile and highly efficient ex situ electrospinning technique is developed to design the carbon nanofiber elastically confined MoS2 nanoflowers flexible electrode. The flexible freestanding electrode exhibits enhanced electronic conductivities and ionic diffusion coefficients, leading to a remarkable high specific capacity (596 mA h g-1 at a current density of 50 mA g-1) and capacity retention (with 89% capacity retention after 1100 cycles at 1 A g-1). This novel idea underscores the potential importance of fabricating various flexible devices other than the sodium-ion battery.

Phosphorus-Doped Hard Carbon Nanofibers Prepared by Electrospinning as an Anode in Sodium-Ion Batteries.

Phosphorus-doped hard carbon nanofibers with macroporous structure were successfully synthesized by electrospinning followed by a thermal treatment process using polyacrylonitrile and H3PO4 as carbon and phosphorus precursors, respectively. X-ray photoelectron spectroscopy analysis reveals that the doped phosphorus atoms can incorporate into the carbon framework and most of them are connecting with carbon atoms to form P-C bond. The (002) plane interlayer spacing was taken from the X-ray diffraction pattern, which shows a large spacing of 3.83 Å for the obtained P-doped hard carbon nanofibers. When used as an anode in sodium-ion batteries, the as-prepared P-doped hard carbon nanofibers can deliver a reversible capacity of 288 and 103 mAh g-1 at a current density of 50 mA g-1 and 2 A g-1, respectively. After 200 cycles at 50 mA g-1, the capacity retention of P-doped hard carbon nanofibers still reaches 87.8%, demonstrating good cycling durability. These excellent electrochemical performances of P-doped hard carbon nanofibers can be attributed to the macroporous structure, large interlayer spacing, and the formation of P-C bond.

Remarkable Effect of Sodium Alginate Aqueous Binder on Anatase TiO2 as High-Performance Anode in Sodium Ion Batteries.

Sodium alginate (SA) is investigated as the aqueous binder to fabricate high-performance, low-cost, environmentally friendly, and durable TiO2 anodes in sodium-ion batteries (SIBs) for the first time. Compared to the conventional polyvinylidene difluoride (PVDF) binder, electrodes using SA as the binder exhibit significant promotion of electrochemical performances. The initial Coulombic efficiency is as high as 62% at 0.1 C. A remarkable capacity of 180 mAh g-1 is achieved with no decay after 500 cycles at 1 C. Even at 10 C (3.4 A g-1), it remains 82 mAh g-1 after 3600 cycles with approximate 100% Coulombic efficiency. TiO2 electrodes with SA binder display less electrolyte decomposition, fewer side reactions, high electrochemistry reaction activity, effective suppression of polarization, and good electrode morphology, which is ascribed to the rich carboxylic groups, high Young's modulus, and good electrochemical stability of SA binder.

3D Electronic Channels Wrapped Large-Sized Na3 V2 (PO4 )3 as Flexible Electrode for Sodium-Ion Batteries.

The development of portable and wearable electronics has aroused the increasing demand for flexible energy-storage devices, especially for the characteristics of high energy density, excellent mechanical properties, simple synthesis process, and low cost. However, the development of flexible electrodes for sodium-ion batteries (SIBs) is still limited due to the intricate production methods and the relatively high-cost of current collectors such as graphene/graphene oxide and carbon nanotubes. Here, the hierarchical 3D electronic channels wrapped large-sized Na3 V2 (PO4 )3 is designed and fabricated by a simple electrospinning technique. As flexible electrode material, it exhibits outstanding electrolyte wettability, together with ultrafast electronic conductivity and high Na-ion diffusion coefficients for SIBs, leading to superior electrochemical performances. A high reversible specific capacity of 116 mA h g-1 (nearly 99% of the theoretical specific capacities) can be obtained at the current density of 0.1 C. Even after a 300-fold current density increased (30 C), the discharge specific capacity of the flexible electrode still remains 63 mA h g-1 . Such an effective concept of fabricating 3D electronic channels for large-sized particles is expected to accelerate the practical applications of flexible batteries at various systems.

Reverse effect of curcumin on CDDP-induced drug-resistance via Keap1/p62-Nrf2 signaling in A549/CDDP cell.

OBJECTIVE: To assess the effect of curcumin on CDDP-induced drug resistance and explore the underlying molecular mechanism through Nrf2 system and autophagy pathway. METHODS: A drug-resistant cell model was established by exposing A549/CDDP cell to 2 µg/mL CDDP. A549/CDDP cell was treated with 20 µg/mL CDDP and 10 µM curcumin. The cell viability and apoptosis level, the signals of Keap1/P62-Nrf2 and autophagy pathway were analyzed. RESULTS: CDDP induction promoted drug-resistant phenotype in A549/CDDP cell and activated autophagy as well as Nrf2 signals in A549/CDDP cell. Meanwhile, curcumin combination attenuated autophagy and Nrf2 activation induced by CDDP, and reversed the drug-resistant phenotype. Notably, curcumin combination augmented Keap1 transcription. Furthermore, Keap1 ablation with short hairpin RNAs hampered the efficacy of curcumin, suggesting Keap1 played a crucial role on reversal effect of curcumin. CONCLUSIONS: The present findings demonstrate that CDDP promotes abnormal activation of Nrf2 pathway and autophagy, leading to drug resistance of A549/CDDP cell. Curcumin attenuates this process and combat drug-resistance through its potent activation on Keap1 transcription, which is essential for interplay between oxidative stress induced Nrf2 activation and autophagy/apoptosis switch.

Building an Electronic Bridge via Ag Decoration To Enhance Kinetics of Iron Fluoride Cathode in Lithium-Ion Batteries.

As a typical multielectron cathode material for lithium-ion batteries, iron fluoride (FeF3) and its analogues suffer from poor electronic conductivity and low actual specific capacity. Herein, we introduce Ag nanoparticles by silver mirror reaction into the FeF3·0.33H2O cathode to build the electronic bridge between the solid (active materials) and liquid (electrolyte) interface. The crystal structures of as-prepared samples are characterized by X-ray diffraction and Rietveld refinement. Moreover, the density of states of FeF3·0.33H2O and FeF3·0.33H2O/Ag (Ag-decorated FeF3·0.33H2O) samples are calculated using the first principle density functional theory. The FeF3·0.33H2O/Ag cathodes exhibit significant enhancements on the electrochemical performance in terms of the cycle performance and rate capability, especially for the Ag-decorated amount of 5%. It achieves an initial capacity of 168.2 mA h g-1 and retains a discharge capacity of 128.4 mA h g-1 after 50 cycles in the voltage range of 2.0-4.5 V. It demonstrates that Ag decoration can reduce the band gap, improve electronic conductivity, and elevate intercalation/deintercalation kinetics.

Multilayered Electride Ca2N Electrode via Compression Molding Fabrication for Sodium Ion Batteries.

Pursuing for novel electrode materials is significant for the progress of sodium ion batteries (SIBs). Here, a multilayered electride prepared by simple thermal decomposition of solid Ca3N2, namely Ca2N, is introduced as a new anode material of SIBs for the first time, and a compression molding electrode fabricated by pressing Ca2N powder into nickel foam is applied to protect Ca2N from trace moisture and oxygen. The as-prepared electrode delivers an initial discharge capacity of 1110.5 mAh g-1 and a reversible discharge capacity of ∼320 mAh g-1. These results suggest that Ca2N has a great potential for sodium ion batteries.