Solubilities of 2-Naphthalenesulfonic Acid Monohydrate and Sodium 2-Naphthalenesulfonate in Sulfuric Acid Solution and Their Application for Preparing Sodium 2-Naphthalenesulfonate

The solubilities of 2-naphthalenesulfonic acid monohydrate and sodium 2-naphthalenesulfonate in sulfuric acid solutions were measured at temperatures ranging from 278,15 to 338.15 K by using a dynamic method. The concentration of sulfuric acid solution ranged from 0 to 80wt%. The solubilities of 2-naphthalenesulfonic acid monohydrate and sodium 2-naphthalenesulfonate increased with temperature, and both of them were the lowest at 70wt% of sulfuric acid solution （ w3 0 = 0.70） while the highest in pure water. The solubility data were correlated by the modified Apelblat equation. Based on the solubility difference between 2-naphthalenesulfonic acid monohydrate and sodium 2-naphthalenesulfonate, a new technique in which sodium sulfate was used to replace sodium sulfite in the neutralization reaction was developed. The suitable mole ratio of H20 to Na2SO4 in the neutralization reaction was 80 ： 1, and that of 2-naphthalenesulfonic acid monohydrate to Na2SO4 was 3.2 ： 1. The material balance under the suitable mole ratios was given and discussed.

Comparative efficacy of sodium glucose cotransporter-2 inhibitors in the management of type 2 diabetes mellitus:A real-world experience

BACKGROUND Sodium glucose cotransporter-2 inhibitors(SGLT-2i)are a class of drugs with modest antidiabetic efficacy,weight loss effect,and cardiovascular benefits as proven by multiple randomised controlled trials(RCTs).However,real-world data on the comparative efficacy and safety of individual SGLT-2i medications is sparse.AIM To study the comparative efficacy and safety of SGLT-2i using real-world clinical data.METHODS We evaluated the comparative efficacy data of 3 SGLT-2i drugs(dapagliflozin,canagliflozin,and empagliflozin)used for treating patients with type 2 diabetes mellitus.Data on the reduction of glycated hemoglobin(HbA1c),body weight,blood pressure(BP),urine albumin creatinine ratio(ACR),and adverse effects were recorded retrospectively.RESULTS Data from 467 patients with a median age of 64(14.8)years,294(62.96%)males and 375(80.5%)Caucasians were analysed.Median diabetes duration was 16.0(9.0)years,and the duration of SGLT-2i use was 3.6(2.1)years.SGLT-2i molecules used were dapagliflozin 10 mg(n=227;48.6%),canagliflozin 300 mg(n=160;34.3%),and empagliflozin 25 mg(n=80;17.1).Baseline median(interquartile range)HbA1c in mmol/mol were:dapagliflozin-78.0(25.3),canagliflozin-80.0(25.5),and empagliflozin-75.0(23.5)respectively.The respective median HbA1c reduction at 12 months and the latest review(just prior to the study)were:66.5(22.8)&69.0(24.0),67.0(16.3)&66.0(28.0),and 67.0(22.5)&66.5(25.8)respectively(P<0.001 for all comparisons from baseline).Significant improvements in body weight(in kilograms)from baseline to study end were noticed with dapagliflozin-101(29.5)to 92.2(25.6),and canagliflozin 100(28.3)to 95.3(27.5)only.Significant reductions in median systolic and diastolic BP,from 144(21)mmHg to 139(23)mmHg;(P=0.015),and from 82(16)mmHg to 78(19)mmHg;(P<0.001)respectively were also observed.A significant reduction of microalbuminuria was observed with canagliflozin only[ACR 14.6(42.6)at baseline to 8.9(23.7)at the study end;P=0.043].Adverse effects of SGLT-2i were as follows:genital thrush and urinary infection-20(8.8%)&17(7.5%)with dapagliflozin;9(5.6%)&5(3.13%)with canagliflozin;and 4(5%)&4(5%)with empagliflozin.Diabetic ketoacidosis was observed in 4(1.8%)with dapagliflozin and 1(0.63%)with canagliflozin.CONCLUSION Treatment of patients with SGLT-2i is associated with statistically significant reductions in HbA1c,body weight,and better than those reported in RCTs,with low side effect profiles.A review of large-scale real-world data is needed to inform better clinical practice decision making.

Hierarchically Structured Nb_(2)O_5 Microflowers with Enhanced Capacity and Fast-Charging Capability for Flexible Planar Sodium Ion Micro-Supercapacitors

Planar Na ion micro-supercapacitors(NIMSCs) that offer both high energy density and power density are deemed to a promising class of miniaturized power sources for wearable and portable microelectron-ics. Nevertheless, the development of NIMSCs are hugely impeded by the low capacity and sluggish Na ion kinetics in the negative electrode.Herein, we demonstrate a novel carbon-coated Nb_(2)O_5 microflower with a hierarchical structure composed of vertically intercrossed and porous nanosheets, boosting Na ion storage performance. The unique structural merits, including uniform carbon coating, ultrathin nanosheets and abun-dant pores, endow the Nb_(2)O_5 microflower with highly reversible Na ion storage capacity of 245 mAh g^(-1) at 0.25 C and excellent rate capability.Benefiting from high capacity and fast charging of Nb_(2)O_5 microflower, the planar NIMSCs consisted of Nb_(2)O_5 negative electrode and activated car-bon positive electrode deliver high areal energy density of 60.7 μWh cm^(-2),considerable voltage window of 3.5 V and extraordinary cyclability. Therefore, this work exploits a structural design strategy towards electrode materials for application in NIMSCs, holding great promise for flexible microelectronics.

Delving into the dissimilarities in electrochemical performance and underlying mechanisms for sodium and potassium ion storage in N-doped carbon-encapsulated metallic Cu_(2)Se nanocubes

The large volumetric variations experienced by metal selenides within conversion reaction result in inferior rate capability and cycling stability,ultimately hindering the achievement of superior electrochemical performance.Herein,metallic Cu_(2)Se encapsulated with N-doped carbon(Cu_(2)Se@NC)was prepared using Cu_(2)O nanocubes as templates through a combination of dopamine polymerization and hightemperature selenization.The unique nanocubic structure and uniform N-doped carbon coating could shorten the ion transport distance,accelerate electron/charge diffusion,and suppress volume variation,ultimately ensuring Cu_(2)Se@NC with excellent electrochemical performance in sodium ion batteries(SIBs)and potassium ion batteries(PIBs).The composite exhibited excellent rate performance(187.7 mA h g^(-1)at 50 A g^(-1)in SIBs and 179.4 mA h g^(-1)at 5 A g^(-1)in PIBs)and cyclic stability(246,8 mA h g^(-1)at 10 A g^(-1)in SIBs over 2500 cycles).The reaction mechanism of intercalation combined with conversion in both SIBs and PIBs was disclosed by in situ X-ray diffraction(XRD)and ex situ transmission electron microscope(TEM).In particular,the final products in PIBs of K_(2)Se and K_(2)Se_(3)species were determined after discharging,which is different from that in SIBs with the final species of Na_(2)Se.The density functional theory calculation showed that carbon induces strong coupling and charge interactions with Cu_(2)Se,leading to the introduction of built-in electric field on heterojunction to improve electron mobility.Significantly,the theoretical calculations discovered that the underlying cause for the relatively superior rate capability in SIBs to that in PIBs is the agile Na~+diffusion with low energy barrier and moderate adsorption energy.These findings offer theoretical support for in-depth understanding of the performance differences of Cu-based materials in different ion storage systems.

Experimental investigation of the effects of oil asphaltene content on CO_(2) foam stability in the presence of nanoparticles and sodium dodecyl sulfate

Foam stability tests were performed using sodium dodecyl sulfate(SDS)surfactant and SiO2 nanoparticles as foaming system at different asphaltene concentrations,and the half-life of CO_(2) foam was measured.The mechanism of foam stability reduction in the presence of asphaltene was analyzed by scanning electron microscope(SEM),UV adsorption spectrophotometric concentration measurement and Zeta potential measurement.When the mass ratio of synthetic oil to foam-formation suspension was 1:9 and the asphaltene mass fraction increased from 0 to 15%,the half-life of SDS-stabilized foams decreased from 751 s to 239 s,and the half-life of SDS/silica-stabilized foams decreased from 912 s to 298 s.When the mass ratio of synthetic oil to foam-formation suspension was 2:8 and the asphaltene mass fraction increased from 0 to 15%,the half-life of SDS-stabilized foams decreased from 526 s to 171 s,and the half-life of SDS/silica-stabilized foams decreased from 660 s to 205 s.In addition,due to asphaltene-SDS/silica interaction in the aqueous phase,the absolute value of Zeta potential decreases,and the surface charges of particles reduce,leading to the reduction of repulsive forces between two interfaces of thin liquid film,which in turn,damages the foam stability.

Interfacial built-in electric field and crosslinking pathways enabling WS_(2)/Ti_(3)C_(2)T_(x) heterojunction with robust sodium storage at low temperature

Developing efficient energy storage for sodium-ion batteries(SIBs)by creating high-performance heterojunctions and understanding their interfacial interaction at the atomic/molecular level holds promise but is also challenging.Besides,sluggish reaction kinetics at low temperatures restrict the operation of SIBs in cold climates.Herein,cross-linking nanoarchitectonics of WS_(2)/Ti_(3)C_(2)T_(x) heterojunction,featuring built-in electric field(BIEF),have been developed,employing as a model to reveal the positive effect of heterojunction design and BIEF for modifying the reaction kinetics and electrochemical activity.Particularly,the theoretical analysis manifests the discrepancy in work functions leads to the electronic flow from the electron-rich Ti_(3)C_(2)T_(x) to layered WS_(2),spontaneously forming the BIEF and“ion reservoir”at the heterogeneous interface.Besides,the generation of cross-linking pathways further promotes the transportation of electrons/ions,which guarantees rapid diffusion kinetics and excellent structure coupling.Consequently,superior sodium storage performance is obtained for the WS_(2)/Ti_(3)C_(2)T_(x) heterojunction,with only 0.2%decay per cycle at 5.0 A g^(-1)(25℃)up to 1000 cycles and a high capacity of 293.5 mA h g^(-1)(0.1A g^(-1)after 100 cycles)even at-20℃.Importantly,the spontaneously formed BIEF,accompanied by“ion reservoir”,in heterojunction provides deep understandings of the correlation between structure fabricated and performance obtained.

Solid-state NMR study on sodium intercalation at low voltage window for Na_(3)V_(2)(PO_(4))_(3) as an anode

In-situ XRD,^(31)P NMR and ^(23)Na NMR were used to analyze the interaction behavior of Na_(3)V_(2)(PO_(4))_(3) at low voltage,and then a new intercalation model was proposed.During the transition from Na_(3)V_(2)(PO_(4))_(3) to Na_(4)V_(2)(PO_(4))_(3),Na ions insert into M1,M2 and M3 sites simultaneously.Afterwards,during the transition of Na_(4)V_(2)(PO_(4))_(3)to Na_(5)V_(2)(PO_(4))_(3),Na ions mainly insert into M3 site.

Extending the solid solution range of sodium ferric pyrophosphate:Off‐stoichiometric Na_(3)Fe(2.5)(P_(2)O_(7))_(2)as a novel cathode for sodium‐ion batteries

Iron‐based pyrophosphates are attractive cathodes for sodium‐ion batteries due to their large framework,cost‐effectiveness,and high energy density.However,the understanding of the crystal structure is scarce and only a limited candidates have been reported so far.In this work,we found for the first time that a continuous solid solution,Na_(4−α)Fe_(2+α)_(2)(P_(2)O_(7))_(2)(0≤α≤1,could be obtained by mutual substitution of cations at center‐symmetric Na3 and Na4 sites while keeping the crystal building blocks of anionic P_(2)O_(7) unchanged.In particular,a novel off‐stoichiometric Na_(3)Fe(2.5)(P_(2)O_(7))_(2)is thus proposed,and its structure,energy storage mechanism,and electrochemical performance are extensively investigated to unveil the structure–function relationship.The as‐prepared off‐stoichiometric electrode delivers appealing performance with a reversible discharge capacity of 83 mAh g^(−1),a working voltage of 2.9 V(vs.Na^(+)/Na),the retention of 89.2%of the initial capacity after 500 cycles,and enhanced rate capability of 51 mAh g^(−1)at a current density of 1600 mA g^(−1).This research shows that sodium ferric pyrophosphate could form extended solid solution composition and promising phase is concealed in the range of Na_(4−α)Fe_(2+α)_(2)(P_(2)O_(7))_(2),offering more chances for exploration of new cathode materials for the construction of high‐performance SIBs.

Sodium-Glucose Cotransporter-2 Inhibitors: Who, When & How? Guidance for Use from a Multidisciplinary Practical Approach

Sodium-glucose cotransporter-2 inhibitors (SGLT-2 inhibitors) have transformed diabetes management by targeting renal glucose reabsorption. Designed initially as antidiabetic agents, their ability to lower blood glucose levels independently of insulin is well-documented. Beyond glycemic control, emerging research has unveiled their profound cardiorenal benefits. By inhibiting SGLT-2 protein, these drugs enhance glucose excretion in urine, reducing blood glucose levels. This mechanism has translated into significant cardiovascular and renal protection, establishing SGLT-2 inhibitors as pivotal in managing not only diabetes but also cardiovascular and renal diseases. Recent studies have illuminated the broader therapeutic potential of SGLT-2 inhibitors beyond diabetes. Evidence indicates their efficacy in managing heart failure, chronic kidney disease (CKD), and cardiovascular complications in individuals with or without diabetes. This expanded therapeutic landscape has catalyzed a paradigm shift in SGLT-2 inhibitor use, positioning them as key agents in the cardiorenal metabolic continuum. Moreover, their role in the secondary prevention of cardiovascular events and slowing CKD progression in T2DM patients has garnered considerable attention. This consensus-based review aims to offer practical guidance in an algorithmic approach to primary care healthcare professionals to optimize SGLT-2 inhibitors utilization and maximize their benefits. The review seeks to empower clinicians to effectively manage patients who may benefit from SGLT-2 inhibitor therapy by addressing common initiation barriers and optimizing treatment strategies. Additionally, it aims to raise awareness among primary care physicians regarding the multifaceted benefits of these medications and overcome clinical inertia in their adoption into routine clinical practice.

钠-葡萄糖协同转运蛋白2抑制剂对急性心肌梗死合并2型糖尿病患者临床指标及预后的影响

目的观察钠-葡萄糖协同转运蛋白2抑制剂(SGLT-2i)对急性心肌梗死(AMI)合并2型糖尿病(T2DM)患者临床指标及预后的影响。方法回顾性选取2020年1月至2022年6月于安徽医科大学第二附属医院胸痛中心就诊后确诊AMI合并T2DM患者180例,根据入院后降糖方案分为对照组(79例,给予磺脲类、α-糖苷酶抑制剂、二甲双胍等药物)和观察组(101例,给予达格列净或恩格列净)。患者出院后定期随访,比较2组患者临床指标及主要不良心血管事件(MACE)发生情况。结果所有患者随访6~12个月,结果显示观察组白细胞计数小于对照组[(7.4±1.6)×10^(9)/L比(8.7±1.6)×10^(9)/L],左心室舒张末期内径改善优于对照组[(-0.527±1.462)mm比(1.359±2.111)mm](均P<0.05)。观察组MACE发生率低于对照组[5.4%(2/37)比25.0%(8/32)],差异有统计学意义(P=0.020)。结论SGLT-2i较其他降糖药物12个月内能改善AMI合并T2DM患者的心脏功能及预后,且能减轻该类患者的全身炎症反应。

20例钠-葡萄糖共转运蛋白2抑制剂致福涅尔坏疽病例及文献分析

目的探讨钠-葡萄糖共转运蛋白2抑制剂(SGLT-2i)致福涅尔坏疽(FG)的发生特点,为临床安全用药提供参考。方法采用计算机检索PubMed、Embase、中国知网、万方、维普数据库自建库起至2023年6月有关SGLT-2i致FG的病例报道,并对相关数据进行统计和分析。结果共纳入20篇文献,涉及20例患者。其中,男14例(70.00%),女6例(30.00%);年龄(56.0±11.5)岁;12例(60.00%)描述为肥胖,其中5例为极重度肥胖(体质量指数不低于40 kg/m^(2))。FG发生中位时间为425 d,FG发生时糖化血红蛋白(HbA_(1C))平均值为9.2%。SGLT-2i致FG相关性为很可能的有8例,可能的有12例。20例患者经停药、及时清创引流及给予抗菌药物治疗后转归均良好。结论临床使用SGLT-2i时需注意识别其致FG的危险因素,一旦生殖器或会阴区域出现可疑的肿胀、疼痛等不适,需立即就医,并给予积极治疗。

Sb_(2)S_(3)/石墨烯负极材料的制备及其储钠性能研究

钠离子电池(sodium-ion batteries,SIBs)具有成本低的潜在优势,有望成为替代锂离子电池(lithium ion batteries,LIBs)的储能设备。为提升钠离子电池的性能,开发出适应钠离子脱嵌的负极材料尤为重要。硫化锑(Sb_(2)S_(3))因其理论比容量高被认为是较好的钠离子电池负极材料。本文使用简单水热法将Sb_(2)S_(3)与石墨烯复合,制备Sb_(2)S_(3)/石墨烯复合材料(Sb_(2)S_(3)/Gr)。结果表明:Sb_(2)S_(3)/Gr作为钠离子电池负极时,不仅表现出良好的电导率(3.5×10~(-3)S/cm)和钠离子扩散速率(4.853×10~(-13)cm~2/s),而且在0.5 A/g的电流密度下,首圈库伦效率为76.27%,经150次循环后的比容量稳定在488 m A·h/g,表现出较高的比容量。Sb_(2)S_(3)/Gr复合材料表现出了极大的应用潜力,为高性能钠离子电池负极材料的研发提供了一定的参考价值。

达格列净对2型糖尿病非增殖期视网膜病变的影响

目的:探讨达格列净对2型糖尿病非增殖期视网膜病变(non-proliferative diabetic retinopathy,NPDR)的影响。方法:选取2021年10月—2023年6月湖南师范大学附属湘东医院收治的88例2型糖尿病NPDR患者。随机将其分为观察组及对照组,各44例。两组均给予常规降糖治疗,观察组加用达格列净治疗。比较两组治疗前后血糖指标及相关指标。分析血管内皮生长因子(vascular endothelial growth factor,VEGF)与血糖波动指标的相关性。结果:治疗后,两组空腹血糖(fasting blood glucose,FBG)、餐后2 h血糖(2 h postprandial blood glucose,2 h PBG)、糖化血红蛋白(glycosylated hemoglobin,HbA1c)、血糖水平标准差(standard deviation of blood glucose,SDBG)、餐后血糖波动幅度(postprandial glucose excursion,PPGE)、最大血糖波动幅度(large amplitude glycemic excursion,LAGE)均下降,观察组SDBG、PPGE、LAGE均低于对照组,差异有统计学意义(P<0.05)。治疗后,两组VEGF、黄斑中心凹厚度均下降,最佳矫正视力(best-corrected visual acuity,BCVA)升高,观察组VEGF、黄斑中心凹厚度均低于对照组,BCVA高于对照组,差异有统计学意义(P<0.05)。Pearson相关性分析结果显示:VEGF与SDBG、PPGE、LAGE均呈正相关(P<0.05)。结论:达格列净能够改善血糖波动,降低VEGF水平,对2型糖尿病NPDR有保护作用。

SGLT-2抑制剂达格列净治疗早期糖尿病肾病的临床效果和安全性分析

目的分析在早期糖尿病肾病治疗中采用钠-葡萄糖协同转运蛋白2(Sodium-dependent Glucose Transporters 2,SGLT-2)抑制剂达格列净的疗效和安全性。方法选取2022年3月—2023年12月北京市第六医院收治的100例早期糖尿病肾病患者为研究对象,以随机数表法分为研究组和对照组,各50例。给予全部患者常规治疗,研究组加用达格列净治疗,对照组加用二甲双胍治疗,对比两组血糖水平、肾功能和不良反应发生情况。结果治疗后,研究组空腹血糖为(5.16±0.77)mmol/L,餐后2 h血糖为(7.11±1.38)mmol/L,糖化血红蛋白为(5.05±0.73)%,低于对照组,差异有统计学意义(t=4.592、5.020、5.093,P均<0.05)。治疗后,研究组尿白蛋白/肌酐比值、肾小球过滤率优于对照组,差异有统计学意义(P均<0.05)。研究组不良反应发生率低于对照组,差异有统计学意义(P<0.05)。结论在早期糖尿病肾病治疗中采用SGLT-2抑制剂达格列净疗效显著,可以有效降低血糖水平,改善肾功能,降低不良反应发生率。

Advances in Studies of Chiglitazar Sodium,a Novel PPAR Pan-Agonist,for the Treatment of Type 2 Diabetes Mellitus

Chiglitazar sodium is a new peroxisome proliferator-activated receptor(PPAR)pan-agonist with independent intellectual property rights in China.It can treat type 2 diabetes mellitus and regulate metabolism by modestly activating PPARα,PPARγ,and PPARδto improve insulin sensitivity,regulate blood glucose,and promote fatty acid oxidation and utilization.Chiglitazar sodium has a significant insulin-sensitizing effect and is advantageous in reducing fasting and postprandial blood glucose levels,particularly at the 48 mg dose in patients with concomitant high triglycerides in terms of blood glucose and triglyceride level control.

Enabling High-Performance Sodium Battery Anodes by Complete Reduction of Graphene Oxide and Cooperative In-Situ Crystallization of Ultrafine SnO_(2)Nanocrystals

The main bottleneck against industrial utilization of sodium ion batteries(SIBs)is the lack of high-capacity electrodes to rival those of the benchmark lithium ion batteries(LIBs).Here in this work,we have developed an economical method for in situ fabrication of nanocomposites made of crystalline few-layer graphene sheets loaded with ultrafine SnO_(2)nanocrystals,using short exposure of microwave to xerogel of graphene oxide(GO)and tin tetrachloride containing minute catalyzing dispersoids of chemically reduced GO(RGO).The resultant nanocomposites(SnO_(2)@MWG)enabled significantly quickened redox processes as SIB anode,which led to remarkable full anode-specific capacity reaching 538 mAh g^(−1)at 0.05 A g^(−1)(about 1.45 times of the theoretical capacity of graphite for the LIB),in addition to outstanding rate performance over prolonged charge–discharge cycling.Anodes based on the optimized SnO_(2)@MWG delivered stable performance over 2000 cycles even at a high current density of 5 A g^(−1),and capacity retention of over 70.4%was maintained at a high areal loading of 3.4 mg cm^(−2),highly desirable for high energy density SIBs to rival the current benchmark LIBs.

简易合成MgCo_(2)O_(4)纳米线及其电化学性能研究

通过水热路径引入表面活性剂十二烷基磺酸钠在泡沫镍上成功合成出比表面积较大、超薄多孔的MgCo_(2)O_(4)纳米线。研究表明,MgCo_(2)O_(4)纳米线展示出紧密交织透明的网格状结构且在5 A/g的电流密度下,比电容高达2128 F/g。在40 A/g的情况下循环6000周次后,比电容保持了原始容量的98.4%。将该纳米线和活性炭分别作为正极和负极组装成非对称超级电容器,其比电容可达65.32 F/g且在功率密度为338.95 W/kg下能量密度可达20.41 Wh/kg。上述结果表明该非对称超级电容器是一个较好的储能装置,在实际应用中拥有良好的潜力。

Sub-nanoscale Engineering of MoO_(2) Clusters for Enhanced Sodium Storage

Smart construction of battery-type anodes with high rate and good mechanical properties is significant for advanced sodium ion capacitors(SICs).Herein,a flexible film consisting of MoO_(2) subnanoclusters encapsulated in nitrogen-doped carbon nanofibers(MoO_(2) SCs@N-CNFs)is designed and synthesized via electrospinning toward SICs as anodes.The strong N-Mo interaction guarantees the stable yet uniform dispersion of high loading MoO_(2) SCs(≈40 wt.%)in the flexible carbonaceous substrate.The sub-nanoscale effect of SCs restrains electrode pulverization and improves the Na+diffusion kinetics,rendering better pseudocapacitance-dominated Na+-storage properties than the nanocrystal counterpart.The MoO_(2) SCs@N-CNFs paper with mass loadings of 2.2–10.1 mg cm^(−2) can be directly used as free-standing anode for SICs,which exhibit high reversible gravimetric/areal capacities both in liquid and quasi-solid-state electrolytes.The assembled flexible SICs competitively exhibit exceptional energy density and cycling stability.More significantly,the sub-nanoscale engineering strategy here is promisingly generalized to future electrode design for other electrochemical energy-related applications and beyond.

Comparative structural and electrochemical properties of mixed P2/O′3-layered sodium nickel manganese oxide prepared by sol-gel and electrospinning methods:Effect of Na-excess content

The effect of Na-excess content in the precursor on the structural and electrochemical performances of sodium nickel manganese oxide(NNMO)prepared by sol-gel and electrospinning methods is investigated in this paper.X-ray diffraction results of the prepared NNMO without adding Na-excess content indicate sodium loss,while the mixed phase of P2/O′3-type layered NNMO presented after adding Na-excess content.Compared with the sol-gel method,the secondary phase of NiO is more suppressed by using the electrospinning method,which is further confirmed by field emission scanning electron microscope images.N_(2) adsorption-desorption isotherms show no remarkably difference in specific surface areas between different preparation methods and Na-excess contents.The analysis of X-ray absorption near edge structure indicates that the oxidation states of Ni and Mn are+2 and+4,respectively.For the electrochemical properties,superior electrochemical performance is observed in the NNMO electrode with a low Na-excess content of 5wt%.The highest specific capacitance is 36.07 F·g^(-1)at0.1 A·g^(-1)in the NNMO electrode prepared by using the sol-gel method.By contrast,the NNMO electrode prepared using the electrospinning method with decreased Na-excess content shows excellent cycling stability of 100%after charge-discharge measurements for 300 cycles.Therefore,controlling the Na excess in the precursor together with the preparation method is important for improving the electrochemical performance of Na-based electrode materials in supercapacitors.

流化床喷雾浸渍制备负载型钠基CO_(2)吸附剂脱碳性能

针对传统钠基CO_(2)固体吸附剂晶粒尺寸大、气体扩散阻力高、负载量有限导致的吸附量低的瓶颈问题,提出了基于流化床喷雾浸渍技术的吸附剂制备新方法。选取γ-Al_(2)O_(3)为载体,高纯度Na_(2)CO_(3)作为活性组分,利用溶液浸渍法和流化床喷雾浸渍法分别制备了载体结构、活性组分负载量不同的多组吸附剂,并基于固定床实验装置结合比表面积和孔隙度分析仪、X射线衍射仪、扫描电子显微镜、X射线荧光光谱分析等手段对吸附剂的CO_(2)吸附性能以及孔隙结构、晶型、表面形态及负载量等关键参数进行表征。研究结果表明,相同活性组分负载量下,采用喷雾浸渍法制备的吸附剂的饱和吸附量和吸附活性皆优于传统浸渍法,其原因在于该方法可以控制活性组分在载体上的负载深度;同时,活性组分多为针状或棒状等利于反应的形态结晶;晶体尺寸较传统溶液浸渍法普遍小10%~20%。尽管如此,载体的孔隙结构,具体如比表面积和孔径分布等参数仍会限制流化床喷雾浸渍技术制备的吸附剂的反应性能。