Nano Research最新文献

As a cathode material for potassium-ion batteries (PIBs), manganese-based layered oxides have attracted widespread attention due to their low cost, ease of synthesis, and high performance. However, the Jahn-Teller effect caused by Mn³⁺ and the irreversible phase transformation of the structure leads to poor cycle stability, limiting the development of layered oxides in PIBs. Herein, we demonstrate the use of phase-transition-free CaTiO₃ as rivets in K_0.5Mn_0.9Ti_0.1O₂ by a simple solid-state method. As verified by the in situ X-ray diffraction, the CaTiO₃ rivets effectively prevent the slippage of the transition metal layer during charge and discharge, inhibiting structural degradation. As a result, the obtained K_0.5Mn_0.9Ti_0.1O₂-0.02CaTiO₃ shows excellent cycling stability and rate performance, with high capacities of 119.3 and 70.1 mAh·g^-1 at 20 and 1000 mA·g^-1, respectively. At 200 mA·g^-1, the capacity retention remains 94.7% after more than 300 cycles. This work represents a new avenue for designing and optimizing layered cathode materials for PIBs and other batteries.

Controlled delivery of proteins and other biologics is a growing medium of therapy for diseases previously untreatable. Here we report a self-assembling, tunable vesicle for the controlled delivery of growth factors and cytokines. Coacervate made of heparin and a biocompatible polycation, PEAD, forms the core of the vesicle; lipids form the membrane of the vesicle. We call this vesicle lipocoacervate (LipCo), which has a high affinity for growth factors and cytokines due to heparin. LipCo is a tunable protein delivery vehicle. The vesicle size is controlled through polymer and salt concentrations. Membrane functionalization enables potential for targeting capabilities with long-term storage through lyophilization. Importantly, the controlled delivery of therapeutics also avoids high toxicity to treated cells in vitro. Here we report on these key principles of LipCo assembly and design.

Organic synthesis chemistry plays a crucial role in supporting social sustainable development and finds widespread applications across various fields. Electrocatalysis, with its benefits of high efficiency, mild reaction conditions, controllability, and environmental friendliness, stands out as one of the most effective strategies for driving the transformation of organic substrates. In recent years, nanocrystals (NCs) and single atom catalysts (SACs) have garnered significant attention in the realm of electrocatalytic organic transformation. This article presents a comprehensive overview of the applications of NCs and SACs in electrocatalytic organic transformation. It delves into advanced catalysts for electrocatalysis of representative substrates, covering both anodic oxidation and cathodic reduction aspects, and addresses their synthesis, characterization, catalytic mechanism, and performance. The ultimate goal of this review is to serve as a valuable reference and a source of inspiration for further exploration into the development of more effective catalysts for electrocatalytic organic transformation.

The electrocatalytic conversion of CO₂ to produce fuels and chemicals holds great promise, not only to provide an alternative to fossil feedstocks, but also to use renewable electricity to convert and recycle the greenhouse gas CO₂ to mitigate climate problems. However, the selectivity and reaction rates for the conversion of CO₂ into desirable carbon-based products, especially multicarbon products with high added value, are still insufficient for commercial applications, which is attributed to insufficiently favourable microenvironmental conditions in the vicinity of the catalyst. The construction of catalysts/electrodes with confined structures can effectively improve the reaction microenvironment in the vicinity of the electrodes and thus effectively direct the reaction towards the desired pathway. In this review, we firstly introduce the effects of the microenvironment at the electrode-electrolyte interface including local pH, local intermediate concentration, and local cation concentration on CO₂ reduction reaction (CO₂RR) as well as the mechanism of action, and then shed light on the microenvironmental modulation within the confined space, and finally and most importantly, introduce the design strategy of CO₂RR catalyst/electrode based on the confinement effect.

Heterogeneous Fenton-like reaction shows great potential for eliminating organic substances (e.g. emerging organic contaminants (EOCs)) in water, which has been widely explored in recent decades. However, the catalytic mechanisms reported in current studies are extremely complicated because multiple mechanisms coexist and contribute to the removal efficiencies. Most importantly, heterogeneous systems show selective oxidation properties, which are crucial for improving the efficiencies in the catalytic elimination of organic substances. Thus, this critical review summarizes and compares the diverse existing mechanisms (non-radical and radical pathways) in heterogeneous catalytic processes based on recent studies. The typical oxidation mechanisms during selective advanced oxidation of EOCs were systematically discussed based on the following sections, including the selective adsorption and generation of reactive oxygen species (ROS) in photo/electron-Fenton and Fenton-like systems. Moreover, the non-radical pathways are discussed in depth by the singlet oxygen, high-valent metal-oxo, electron transfer process, etc. Moreover, the direct oxidative transfer process for the removal of EOCs was introduced in recent studies. Finally, the cost, feasibility as well as the sustainability of heterogeneous Fenton-like catalysts are summarized. This review offers useful guidance for developing suitable strategies to develop materials for decomposing the organic substrates.

Sulfide-based solid-state electrolytes (SSEs) with high Li⁺ conductivity ((sigma_{text{Li}^{+}})) and trifling grain boundaries have great potential for all-solid-state lithium-metal batteries (ASSLMBs). Nonetheless, the in-situ development of mixed ionic-electronic conducting solid-electrolyte interphase (SEI) at sulfide electrolyte/Li-metal anode interface induces uneven Li electrodeposition, which causes Li-dendrites and void formation, significantly severely deteriorating ASSLMBs. Herein, we propose a dual anionic, e.g., F and N, doping strategy to Li₇P₃S₁₁, tuning its composition in conjunction with the chemistry of SEI. Therefore, novel Li_6.58P_2.76N_0.03S_10.12F_0.05 glass-ceramic electrolyte (Li₇P₃S₁₁-5LiF-3Li₃N-gce) achieved superior ionic (4.33 mS·cm⁻¹) and lowest electronic conductivity of 4.33 × 10⁻¹⁰ S·cm⁻¹ and thus, offered superior critical current density of 0.90 mA·cm⁻² (2.5 times > Li₇P₃S₁₁) at room temperature (RT). Notably, Li//Li cell with Li_6.58P_2.76N_0.03S_10.12F_0.05-gce cycled stably over 1000 and 600 h at 0.2 and 0.3 mA·cm⁻² credited to robust and highly conductive SEI (in-situ) enriched with LiF and Li₃N species. Li₃N’s wettability renders SEI to be highly Li⁺ conductive, ensures an intimate interfacial contact, blocks reductive reactions, prevents Li-dendrites and facilitates fast Li⁺ kinetics. Consequently, LiNi_0.8Co_0.15Al_0.05O₂ (NCA)/Li_6.58P_2.76N_0.03S_10.12F_0.05-gce/Li cell exhibited an outstanding first reversible capacity of 200.8/240.1 mAh·g⁻¹ with 83.67% Coulombic efficiency, retained 85.11% of its original reversible capacity at 0.3 mA·cm⁻² over 165 cycles at RT.

Intrinsic ferroelectric materials play a critical role in the development of high-density integrated device. Despite some two-dimensional (2D) ferroelectrics have been reported, the research on one-dimensional (1D) intrinsic ferroelectric materials remains relatively scare since 1D atomic structures limit their van der Waals (vdW) epitaxy growth. Here, we report the synthesis of 1D intrinsic vdW ferroelectric SbSI nanowires via a confined-space chemical vapor deposition. By precisely controlling the partial vapor pressure of I₂ and reaction temperature, we can effectively manipulate kinetics and thermodynamics processes, and thus obtain high quality of SbSI nanowires, which is determined by Raman spectroscopy and high-resolution scanning transmission electron microscopy characterizations. The ferroelectricity in SbSI is confirmed by piezo-response force microscopy measurements and the ferroelectric transition temperature of 300 K is demonstrated by second harmonic generation. Moreover, the in-plane polarization switching can be maintained in the thin SbSI nanowires with a thickness of 20 nm. Our prepared 1D vdW ferroelectric SbSI nanowires not only enrich the vdW ferroelectric systems, but also open a new possibility for high-power energy storage nanodevices.