High‐Performance Sodium‐Ion Hybrid Supercapacitor Based on Nb2O5@Carbon Core–Shell Nanoparticles and Reduced Graphene Oxide Nanocomposites

Sodium‐ion hybrid supercapacitors (Na‐HSCs) have potential for mid‐ to large‐scale energy storage applications because of their high energy/power densities, long cycle life, and the low cost of sodium. However, one of the obstacles to developing Na‐HSCs is the imbalance of kinetics from different charge storage mechanisms between the sluggish faradaic anode and the rapid non‐faradaic capacitive cathode. Thus, to develop high‐power Na‐HSC anode materials, this paper presents the facile synthesis of nanocomposites comprising Nb₂O₅@Carbon core–shell nanoparticles (Nb₂O₅@C NPs) and reduced graphene oxide (rGO), and an analysis of their electrochemical performance with respect to various weight ratios of Nb₂O₅@C NPs to rGO (e.g., Nb₂O₅@C, Nb₂O₅@C/rGO‐70, ‐50, and ‐30). In a Na half‐cell configuration, the Nb₂O₅@C/rGO‐50 shows highly reversible capacity of ≈285 mA h g^?1 at 0.025 A g^?1 in the potential range of 0.01–3.0 V (vs Na/Na⁺). In addition, the Na‐HSC using the Nb₂O₅@C/rGO‐50 anode and activated carbon (MSP‐20) cathode delivers high energy/power densities (≈76 W h kg^?1 and ≈20 800 W kg^?1) with a stable cycle life in the potential range of 1.0–4.3 V. The energy and power densities of the Na‐HSC developed in this study are higher than those of similar Li‐ and Na‐HSCs previously reported.     

Understanding the Structural Evolution and Redox Mechanism of a NaFeO2–NaCoO2 Solid Solution for Sodium‐Ion Batteries

Na‐ion batteries have become promising candidates for large‐scale energy‐storage systems because of the abundant Na resources and they have attracted considerable academic interest because of their unique behavior, such as their electrochemical activity for the Fe³⁺/Fe⁴⁺ redox couple. The high‐rate performance derived from the low Lewis‐acidity of the Na⁺ ions is another advantage of Na‐ion batteries and has been demonstrated in NaFe_1/2Co_1/2O₂ solutions. Here, a solid solution of NaFeO₂‐NaCoO₂ is synthesized and the mechanisms behind their excellent electrochemical performance are studied in comparison to those of their respective end‐members. The combined analysis of operando X‐ray diffraction, ex situ X‐ray absorption spectroscopy, and density functional theory (DFT) calculations for Na_{1– x} Fe_1/2Co_1/2O₂ reveals that the O3‐type phase transforms into a P3‐type phase coupled with Na⁺/vacancy ordering, which has not been observed in O3‐type NaFeO₂. The substitution of Co for Fe stabilizes the P3‐type phase formed by sodium extraction and could suppress the irreversible structural change that is usually observed in O3‐type NaFeO₂, resulting in a better cycle retention and higher rate performance. Although no ordering of the transition metal ions is seen in the neutron diffraction experiments, as supported by Monte‐Carlo simulations, the formation of a superlattice originating from the Na⁺/vacancy ordering is found by synchrotron X‐ray diffraction for Na_0.5Fe_1/2Co_1/2O₂, which may involve a potential step in the charge/discharge profiles.     

Understanding Origin of Voltage Hysteresis in Conversion Reaction for Na Rechargeable Batteries: The Case of Cobalt Oxides

Conversion reaction electrodes offer a high specific capacity in rechargeable batteries by utilizing wider valence states of transition metals than conventional intercalation‐based electrodes and have thus been intensively studied in recent years as potential electrode materials for high‐energy‐density rechargeable batteries. However, several issues related to conversion reactions remain poorly understood, including the polarization or hysteresis during charge/discharge processes. Herein, Co₃O₄ in Na cells is taken as an example to understand the aforementioned properties. The large hysteresis in charge/discharge profiles is revealed to be due to different electrochemical reaction paths associated with respective charge and discharge processes, which is attributed to the mobility gap among inter‐diffusing species in a metal oxide compound during de/sodiation. Furthermore, a Co₃O₄–graphene nanoplatelet hybrid material is demonstrated to be a promising anode for Na rechargeable batteries, delivering a capacity of 756 mAh g^?1 with a good reversibility and an energy density of 96 Wh kg^?1 (based on the total electrode weight) when combined with a recently reported Na₄Fe₃(PO₄)₂(P₂O₇) cathode.     

多硫化钠复合型缓蚀剂的性能

在实验室模拟茂名石化加压空冷器系统的腐蚀溶液,运用室内静态挂片失重法及 CMB-1510B 便携式瞬时腐蚀速度测量仪评价了多硫化钠复合缓蚀剂的缓蚀性能,考察了缓蚀剂的浓度和协同效应对缓蚀效果的影响。对实验结果进行了俄歇电子能谱分析和电镜扫描。结果表明,多硫化钠与苯并三唑复合缓蚀剂是一种应用于反应流出物空冷器系统的优良缓蚀剂。在复合缓蚀剂中,当多硫化钠含量为50μg/g、苯并三唑质量浓度为10 mg/L 时,缓蚀效率可达94.8%。     

Sodium Lactate Affects Pathogens in Cooked Beef

Cooked, quartered beef top rounds containing either 1, 2, 3 or 4% sodium lactate were aseptically sampled and slice sections were inoculated with Listeria monocytogenes (ATCC 43256), Staphylococcus aureus (ATCC 27154), Salmonella typhimurium (ATCC 13311), Clostridium perfringens (ATCC 12924), or Escherichia coli O157:H7 (ATCC 43895). Inoculated slices were stored at 10°C for 0. 7. 14. 21 or 28 days.‘Three and 4% sodium lactate generally displayed lim-ited proliferation of S. typhimurium, L. monocytogenes and E. coli O157:H7 when compared with control roasts (0% sodium lactate) and roasts containing 2% sodium lactate.     

从氯化铅渣中回收铅铋的研究

本文以柿竹园有色金属矿粗铋火法精炼、气化除铅产出的铅渣为原料，在常压下采用氯化钠水溶液进行浸出处理，有效地分离了铅和铋，并将铅制成了化工产品黄丹及硫酸铅     

土壤理化性质对TPH污染土壤氧化修复的影响研究

目的 为探究土壤理化性质对总石油烃(TPH)污染土壤氧化修复效果的影响,进而寻求针对TPH污染土壤的高效氧化体系。方法 选用西南地区紫色土分别配制不同土壤有机质含量、粒径、阳离子交换量的TPH污染土壤,选取CaO₂类芬顿、活化Na₂S₂O₈、CaO₂/Na₂S₂O₈复合氧化体系,以各自最优氧化条件在室温25℃的条件下进行氧化实验,考查土壤理化性质对土壤TPH负载能力及氧化修复效果的影响。结果 在TPH投加量均为15 000 mg/kg的条件下,土壤TPH负载能力与土壤有机质含量、阳离子交换量呈正相关,与土壤粒径呈负相关,其影响程度为：有机质含量>粒径>阳离子交换量;土壤TPH降解率与土壤有机质含量、阳离子交换量及粒径皆呈负相关,其影响程度为：粒径>有机质含量>阳离子交换量。结论 在各体系最优氧化条件下,CaO₂/Na₂S₂O...     

Effects of SO2 and SO3 on the Na2SO4 induced corrosion of nickel

The effects of SO₂ and SO₃ in the environment on the hot corrosion behavior of Ni in the temperature range 750–950°C has been studied. Below the melting point of Na₂SO₄ (884°C), rapid corrosion takes place by formation of a Na₂SO₄-NiSO₄ melt, which can penetrate the porous oxide scale and give rise to sulfide information by coming in contact with the metal. The distribution of the sulfides depends on the SO₂ level in the ambient gas. Continued corrosion occurs by a sulfidation-oxidation mechanism. At temperatures above the melting point of Na₂SO₄, accelerated degradation occurs via dissolution of the surface scale, followed by reprecipitation of the oxide in a nonprotective form.Deceased     

Facile electrosynthsis of poly (pyrene-1-sulfonic acid sodium salt) film: A good candidate for blue light-emitting diodes applications

Pyrene-1-sulfonic acid sodium salt (PyS) was chemically synthesized, and its polymer film, poly (pyrene-1-sulfonic acid sodium salt) (PPyS), was successfully electropolymerized by direct anodic oxidation both in aqueous and boron trifluoride diethyl etherate (BFEE) systems. The PPyS films showed good redox activity and structural stability even in SA. The impedance spectra of PPyS films indicated that the electron transfer resistance was about 23 Ω. The fluorescent result exhibited that the emission band of PPyS was red-shifed at least 76 nm in comparison with the monomer. Both the impedance and the fluorescent spectra demonstrated that the PPyS films were good semiconducting polymer and excellent blue-light-emitting materials, respectively.     

再生橡胶制备中氧化程度控制对再生橡胶性能的影响

通过添加过氧化氢或过碳酸钠考察废胶粉再生过程中氧化程度对再生橡胶性能的影响。结果表明:废胶粉再生配方中添加过氧化氢或过碳酸钠后,再生橡胶的溶胶质量分数增大,门尼粘度下降,强伸性能有所改善;综合考虑再生橡胶的加工性能和强伸性能,过氧化氢用量以0.7份为宜,过碳酸钠用量以1.8份为宜,过碳酸钠的再生效果更好。