Modulating the Electrolyte Microenvironment in Electrical Double Layer for Boosting Electrocatalytic Nitrate Reduction to Ammonia.

Electrochemical nitrate reduction reaction (NO3RR) is a promising approach to achieve remediation of nitrate-polluted wastewater and sustainable production of ammonia. However, it is still restricted by the low activity, selectivity and Faraday efficiency for ammonia synthesis. Herein, we propose an effective strategy to modulate the electrolyte microenvironment in electrical double layer (EDL) by mediating alkali metal cations in the electrolyte to enhance the NO3RR performance. Taking bulk Cu as a model catalyst, the experimental study reveals that the NO3 --to-NH3 performance in different electrolytes follows the trend Li+

Highly sensitive determination of L-glutamic acid in pig serum with an enzyme-free molecularly imprinted polymer on a carbon-nanotube modified electrode.

Through electrochemical polymerization using L-glutamic acid (L-Glu) as a template and 4,6-diaminoresorcinol as a functional monomer, an enzyme-free molecularly imprinted polymer (MIP) based L-Glu sensor with multi-walled carbon nanotubes (MWCNTs) decorated on a glassy carbon electrode (GCE), namely G-MIP/MWCNTs/GCE, was developed in this work. The reaction conditions were optimized as follows: electrochemical polymerization of 23 cycles, pH of 3.0, molar ratio of template/monomer of 1 : 4, volume ratio of elution reagents of acetonitrile/formic acid of 1 : 1, and elution time of 2 min. The prepared materials and molecularly imprinted polymer were characterized by using scanning electron microscopy (SEM) and transmission electron microscopy (TEM) as well as electrochemical methods. The electrochemical properties of different electrodes were investigated via differential pulse voltammetry (DPV), showing that the electrode of G-MIP/MWCNTs/GCE exhibited excellent catalytic oxidation activity towards L-Glu. A good linear relationship between peak-currents and L-Glu concentrations in a range from 1.00 × 10-8 to 1.00 × 10-5 mol L-1 was observed, with a detection limit of 5.13 × 10-9 mol L-1 (S/N = 3). The imprinted sensor possesses excellent selectivity, high sensitivity, and good stability, which have been successfully applied for the detection of L-Glu in pig serum samples with a recovery rate of 97.4-105.5%, being comparable to commercial high-performance liquid chromatography, demonstrating a simple, rapid, and accurate way for the determination of L-Glu in the fields of animal nutrition and biomedical engineering.

In situ reconstructed AgZn3 nanoparticles supported on zinc nanoplates for efficient CO2 electroreduction to tunable syngas.

Developing efficient electrocatalysts for CO2 reduction to syngas with tunable H2/CO ratios and high total faradaic efficiency is challenging. Herein, we report an effective catalyst composed of in situ reconstructed AgZn3 nanoparticles and Zn nanoplates for syngas synthesis, showing nearly 100% Faraday efficiency to syngas with a tunable H2/CO ratio from 2 : 1 to 1 : 2. Moreover, the in situ electrochemical measurements coupled with theoretical calculations disclose that the Zn site in AgZn3 nanoparticles and the hollow site between Ag and Zn in AgZn3 are the possible active sites for CO and H2 generation, respectively. This work has guiding significance for designing dual site catalysts for CO2 electroreduction to tunable syngas.

Dynamic Reconstructed RuO2 /NiFeOOH with Coherent Interface for Efficient Seawater Oxidation.

Developing efficient oxygen evolution reaction (OER) electrocatalysts for seawater electrolysis is still a big challenge. Herein, a facile one-pot approach is reported to synthesize RuO2 -incorporated NiFe-metal organic framework (RuO2 /NiFe-MOF) with unique nanobrick-nanosheet heterostructure as precatalyst. Driven by electric field, the RuO2 /NiFe-MOF dynamically reconstructs into RuO2 nanoparticles-anchored NiFe oxy/hydroxide nanosheets (RuO2 /NiFeOOH) with coherent interface, during which the dissolution and redeposition of RuO2 are witnessed. Owing to the synergistic interaction between RuO2 and NiFeOOH, the as-reconstructed RuO2 /NiFeOOH exhibits outstanding alkaline OER activity with an ultralow overpotential of 187.6 mV at 10 mA cm-2 and a small Tafel slope of 31.9 mV dec-1 and excellent durability at high current densities of 840 and 1040 mA cm-2 in 1 m potassium hydroxide (KOH). When evaluated for seawater oxidation, the RuO2 /NiFeOOH only needs a low overpotential of 326.2 mV to achieve 500 mA cm-2 and can continuously catalyze OER at 500 mA cm-2 for 100 h with negligible activity degradation. Density function theory calculations reveal that the presence of strong interaction and enhanced charge transfer along the coherent interface between RuO2 and NiFeOOH ensures improved OER activity and stability.

Ferroptosis:Mechanism and Role in Malignant Tumors / 中国医学科学院学报

Ferroptosis is a new type of programmed cell death different from other cell death pathways such as apoptosis,autophagy,necrosis,and pyroptosis in terms of initiation,mechanisms,and molecular characteristics.As the accumulation of phospholipid hydroperoxides is the hallmark of ferroptosis,the balance between oxidative damage and antioxidant defense is critical to the regulatory mechanism of ferroptosis.In cancer,the upregulation of antioxidant defense pathways can inhibit ferroptosis,thereby promoting cancer cells to survive the oxidative stress and develop drug resistance.This review systematically introduces the main features and regulatory mechanisms of ferroptosis.In addition,we summarize the role of ferroptosis in the progression and drug resistance of malignant tumors,providing novel implications for further research on the pathogenesis of malignant tumors and discovery of new targets for anti-cancer therapy.

The risk variant rs11836367 contributes to breast cancer onset and metastasis by attenuating Wnt signaling via regulating NTN4 expression.

Most genome-wide association study (GWAS)-identified breast cancer-associated causal variants remain uncharacterized. To provide a framework of understanding GWAS-identified variants to function, we performed a comprehensive study of noncoding regulatory variants at the NTN4 locus (12q22) and NTN4 gene in breast cancer etiology. We find that rs11836367 is the more likely causal variant, disrupting enhancer activity in both enhancer reporter assays and endogenous genome editing experiments. The protective T allele of rs11837367 increases the binding of GATA3 to the distal enhancer and up-regulates NTN4 expression. In addition, we demonstrate that loss of NTN4 gene in mice leads to tumor earlier onset, progression, and metastasis. We discover that NTN4, as a tumor suppressor, can attenuate the Wnt signaling pathway by directly binding to Wnt ligands. Our findings bridge the gaps among breast cancer-associated single-nucleotide polymorphisms, transcriptional regulation of NTN4, and breast cancer biology, which provides previously unidentified insights into breast cancer prediction and prevention.

Oxygen Vacancy Engineering Synergistic with Surface Hydrophilicity Modification of Hollow Ru Doped CoNi-LDH Nanotube Arrays for Boosting Hydrogen Evolution.

With the development of clean hydrogen energy, the cost effective and high-performance hydrogen evolution reaction (HER) electrocatalysts are urgently required. Herein, a green, facile, and time-efficient Ru doping synergistic with air-plasma treatment strategy is reported to boost the HER performance of CoNi-layered double hydroxide (LDH) nanotube arrays (NTAs) derived from zeolitic imidazolate framework nanorods. The Ru doping and air-plasma treatment not only regulate the oxygen vacancy to optimize the electron structure but also increase the surface roughness to improve the hydrophilicity and hydrogen spillover efficiency. Therefore, the air plasma treated Ru doped CoNi-LDH (P-Ru-CoNi-LDH) nanotube arrays display superior HER performance with an overpotential of 29 mV at a current density of 10 mA cm-2 . Furthermore, by assembling P-Ru-CoNi-LDH as both cathode and anode for two-electrode urea-assisted water electrolysis, a small cell voltage of 1.36 V is needed at 10 mA cm-2 and can last for 100 h without any obvious activity attenuation that showing outstanding durability. In general, the P-Ru-CoNi-LDH can improve the HER performance from intrinsic electronic structure regulation cooperated with extrinsic surface wettability modification. These findings provide an effective intrinsic and extrinsic synergistic effect avenue to develop high performance HER electrocatalysts, which is potential to be applied to other research fields.

Accelerating the oxygen evolution reaction kinetics of Co3O4 in neutral electrolyte by decorating RuO2.

Developing efficient electrocatalysts for the neutral oxygen evolution reaction (OER) is important but still challenging. Herein, by combining density functional theory calculations and experiments, we have demonstrated that the decoration of RuO2 can effectively accelerate the OER kinetics of Co3O4 in neutral electrolyte. High activity (365 mV at 10 mA cm-2) and decent stability (up to 100 h) are achieved by RuO2-decorated Co3O4 in 1 M PBS electrolyte.

N2 plasma-activated NiO nanosheet arrays with enhanced water splitting performance.

NiO is a promising electrocatalyst for electrochemical energy conversion due to its rich redox sites, low cost, and ease of synthesis. However, hindered by low electrical conductivity and limited electrocatalytic active sites, bare NiO usually exhibits poor electrochemical performance towards hydrogen evolution reaction (HER) and oxygen evolution reaction (OER). Herein, we develop an N2 plasma activation approach to simultaneously improve both HER and OER activity of NiO by constructing heterostructured Ni/Ni3N/NiO nanosheet arrays on Ni foam. The optimized N2 plasma-activated NiO nanosheet arrays for HER and OER (denoted as P-NiO-HER and P-NiO-OER) only need an overpotential of 46 and 294 mV, respectively, to achieve 10 mA cm-2. Moreover, for overall water splitting, the assembled electrolysis cell with P-NiO-HER and P-NiO-OER as the cathode and anode, respectively, only requires a small voltage of 1.57 V to deliver 10 mA cm-2. Remarkably, the plasma-activated NiO nanosheet arrays exhibit excellent stability for up to 50 h for HER, OER, and full water electrolysis. The strategy developed here to activate the electrocatalytic performance of metal oxides opens a new door for water splitting.

Fe ions modulated formation of hollow NiFe oxyphosphide spheres with enhanced oxygen evolution performance.

A facile template-engaged strategy is developed to synthesize hollow NiFe mixed metal oxyphosphide spheres using different Fe ions (Fe2+ and Fe3+) as modulators. Benefiting from the optimized compositional and structural features, the as-obtained hollow spheres show excellent performance for the oxygen evolution reaction.

Formation of uniform porous yolk-shell MnCo2O4 microrugby balls with enhanced electrochemical performance for lithium storage and the oxygen evolution reaction.

Mixed transition metal oxides with favorable electrochemical properties are promising electrode materials in energy storage and conversion systems. In this work, uniform porous yolk-shell MnCo2O4 (denoted as YSM-MCO) microrugby balls have been synthesized by simple annealing treatment of metal carbonates with a microrugby ball shape in air. Benefiting from the desired porous structure and composition, the as-synthesized YSM-MCO exhibits enhanced electrochemical performance when investigated as anode materials for lithium-ion batteries and electrocatalysts for the oxygen evolution reaction. The YSM-MCO demonstrates remarkable lithium storage properties with a good cycling stability (94% capacity retention over 200 cycles at 0.5 A g-1) and superior rate capability (414 mA h g-1 at 5 A g-1). In addition, the YSM-MCO also exhibits better OER activity than most of the reported MnCo2O4-based electrocatalysts.

Bullet-like Cu9 S5 Hollow Particles Coated with Nitrogen-Doped Carbon for Sodium-Ion Batteries.

Metal sulfides with excellent redox reversibility and high capacity are very promising electrode materials for sodium-ion batteries. However, their practical application is still hindered by the poor rate capability and limited cycle life. Herein, a template-based strategy is developed to synthesize nitrogen-doped carbon-coated Cu9 S5 bullet-like hollow particles starting from bullet-like ZnO particles. With the structural and compositional advantages, these unique nitrogen-doped carbon-coated Cu9 S5 bullet-like hollow particles manifest excellent sodium storage properties with superior rate capability and ultra-stable cycling performance.

The Design and Synthesis of Hollow Micro-/Nanostructures: Present and Future Trends.

Hollow micro-/nanostructures have attracted tremendous interest owing to their intriguing structure-induced physicochemical properties and great potential for widespread applications. With the development of modern synthetic methodology and analytical instruments, a rapid structural/compositional evolution of hollow structures from simple to complex has occurred in recent decades. Here, an updated overview of research progress made in the synthesis of hollow structures is provided. After an introduction of definition and classification, achievements in synthetic approaches for these delicate hollow architectures are presented in detail. According to formation mechanisms, these strategies can be categorized into four different types, including hard-templating, soft-templating, self-templated, and template-free methods. In particular, the rationales and emerging innovations in conventional templating syntheses are in focus. The development of burgeoning self-templating strategies based on controlled etching, outward diffusion, and heterogeneous contraction is also summarized. In addition, a brief overview of template-free methods and recent advances on combined mechanisms is provided. Notably, the strengths and weaknesses of each category are discussed in detail. In conclusion, a perspective on future trends in the research of hollow micro-/nanostructures is given.

Formation of Polypyrrole-Coated Sb2 Se3 Microclips with Enhanced Sodium-Storage Properties.

Antimony-based electrode materials with high specific capacity have aroused considerable interest as anode materials for sodium-ion batteries (SIBs). Herein, we develop a template-engaged ion-exchange method to synthesize Sb2 Se3 microclips, and the as-obtained Sb2 Se3 microclips are further in situ coated with polypyrrole (PPy). Benefiting from the structural and compositional merits, these PPy-coated Sb2 Se3 microclips exhibit enhanced sodium-storage properties in terms of high reversible capacity, superior rate capability, and stable cycling performance.

Formation of Hierarchical Cu-Doped CoSe2 Microboxes via Sequential Ion Exchange for High-Performance Sodium-Ion Batteries.

Electrode materials based on electrochemical conversion reactions have received considerable interest for high capacity anodes of sodium-ion batteries. However, their practical application is greatly hindered by the poor rate capability and rapid capacity fading. Tuning the structure at nanoscale and increasing the conductivity of these anode materials are two effective strategies to address these issues. Herein, a two-step ion-exchange method is developed to synthesize hierarchical Cu-doped CoSe2 microboxes assembled by ultrathin nanosheets using Co-Co Prussian blue analogue microcubes as the starting material. Benefitting from the structural and compositional advantages, these Cu-doped CoSe2 microboxes with improved conductivity exhibit enhanced sodium storage properties in terms of good rate capability and excellent cycling performance.

Hierarchical core-shell structures of P-Ni(OH)2 rods@MnO2 nanosheets as high-performance cathode materials for asymmetric supercapacitors.

The hierarchical porous structure with phosphorus-doped Ni(OH)2 (P-Ni(OH)2) rods as the core and MnO2 nanosheets as the shell is fabricated directly by growth on a three-dimensional (3D) flexible Ni foam (NF) via a two-step hydrothermal process. As a binder-free electrode material, this unique hybrid structure exhibits excellent electrochemical properties, including an ultrahigh areal capacitance of 5.75 F cm-2 at a current density of 2 mA cm-2 and great cyclic stability without capacitance loss at a current density of 20 mA cm-2 after 10 000 cycles. Moreover, an all-solid-state asymmetric supercapacitor (AAS) based on a P-Ni(OH)2@MnO2 hybrid structure on Ni foam as the cathode and activated carbon (AC) as the anode is successfully assembled to enhance value the electrochemical properties. The AAS device also shows excellent electrochemical properties including a large potential window of 0∼1.6 V, an areal capacitance is 911.3 mF cm-2 at a current density of 1 mA cm-2 and long-term cycling performance. Meanwhile, the AAS device also delivers a high energy density of 0.324 mW h cm-2 at a power density of 0.8 mW cm-2; and can easily light colorful light-emitting diode (LED) lights, suggesting that 3D P-Ni(OH)2@MnO2 hybrid composite has promising potential for practical use in high-performance supercapacitors.

Complex Nanostructures from Materials based on Metal-Organic Frameworks for Electrochemical Energy Storage and Conversion.

Metal-organic frameworks (MOFs) have drawn tremendous attention because of their abundant diversity in structure and composition. Recently, there has been growing research interest in deriving advanced nanomaterials with complex architectures and tailored chemical compositions from MOF-based precursors for electrochemical energy storage and conversion. Here, a comprehensive overview of the synthesis and energy-related applications of complex nanostructures derived from MOF-based precursors is provided. After a brief summary of synthetic methods of MOF-based templates and their conversion to desirable nanostructures, delicate designs and preparation of complex architectures from MOFs or their composites are described in detail, including porous structures, single-shelled hollow structures, and multishelled hollow structures, as well as other unusual complex structures. Afterward, their applications are discussed as electrode materials or catalysts for lithium-ion batteries, hybrid supercapacitors, water-splitting devices, and fuel cells. Lastly, the research challenges and possible development directions of complex nanostructures derived from MOF-based-templates for electrochemical energy storage and conversion applications are outlined.

Hierarchical Nanotubes Constructed by Carbon-Coated Ultrathin SnS Nanosheets for Fast Capacitive Sodium Storage.

Tin(II) sulfide (SnS) has been an attractive anode material for sodium ion batteries. Herein, an elegant templating method has been developed for the rational design and synthesis of hierarchical SnS nanotubes composed of ultrathin nanosheets. In order to enhance the electrochemical performance, carbon coated hierarchical SnS nanotubes (denoted as SnS@C nanotubes) have also been obtained by simply adding glucose into the reaction system. Benefiting from their unique structural merits, the SnS@C nanotubes exhibit enhanced sodium storage properties in terms of good cycling performance and superior rate capability.

A Practical High-Energy Cathode for Sodium-Ion Batteries Based on Uniform P2-Na0.7 CoO2 Microspheres.

Layered metal oxides have attracted increasing attention as cathode materials for sodium-ion batteries (SIBs). However, the application of such cathode materials is still hindered by their poor rate capability and cycling stability. Here, a facile self-templated strategy is developed to synthesize uniform P2-Na0.7 CoO2 microspheres. Due to the unique microsphere structure, the contact area of the active material with electrolyte is minimized. As expected, the P2-Na0.7 CoO2 microspheres exhibit enhanced electrochemical performance for sodium storage in terms of high reversible capacity (125 mAh g-1 at 5 mA g-1 ), superior rate capability and long cycle life (86 % capacity retention over 300 cycles). Importantly, the synthesis method can be easily extended to synthesize other layered metal oxide (P2-Na0.7 MnO2 and O3-NaFeO2 ) microspheres.

Carbon-Incorporated Nickel-Cobalt Mixed Metal Phosphide Nanoboxes with Enhanced Electrocatalytic Activity for Oxygen Evolution.

Hollow nanostructures have attracted increasing research interest in electrochemical energy storage and conversion owing to their unique structural features. However, the synthesis of hollow nanostructured metal phosphides, especially nonspherical hollow nanostructures, is rarely reported. Herein, we develop a metal-organic framework (MOF)-based strategy to synthesize carbon incorporated Ni-Co mixed metal phosphide nanoboxes (denoted as NiCoP/C). The oxygen evolution reaction (OER) is selected as a demonstration to investigate the electrochemical performance of the NiCoP/C nanoboxes. For comparison, Ni-Co layered double hydroxide (Ni-Co LDH) and Ni-Co mixed metal phosphide (denoted as NiCoP) nanoboxes have also been synthesized. Benefiting from their structural and compositional merits, the as-synthesized NiCoP/C nanoboxes exhibit excellent electrocatalytic activity and long-term stability for OER.