The preparation and properties of N-doped carbon materials and their use for sodium storage

Defect engineering by heteroatom doping gives carbon materials some new characteristics such as a different electronic structure and a high electrochemical activity,making them suitable for high-performance applications.N-doping has been widely investigated because of its similar atom radius to carbon,high electronegativity as well as many different configurations.We summarize the preparation methods and properties of N-doped carbon materials,and discuss their possible use in sodium ion storage.The relationships between N content/configuration and crystallinity,electronic conductivity,wettability,chemical reactivity as well as sodium ion storage performance are discussed.

采用两步炭化法和熔盐模板法制备N、S共掺杂煤基硬炭及共储钠性能

硬炭因资源丰富、结构稳定及安全性高等优势,已成为钠离子电池常用阳极材料。其中,煤基衍生硬炭受到了广泛的关注。本工作以长焰煤为碳源,硫脲为氮硫源,NaCl为模板,通过两步炭化工艺和杂原子掺杂相结合的方法合成了N和S共掺杂的煤基硬炭(NSPC1200)。两步炭化过程在调节碳微晶结构和扩大层间距方面发挥了重要的作用。N和S的共掺杂调节了炭材料的电子结构,赋予其更多的活性位点;此外,引入NaCl作为模板有助于孔结构的构建,有利于电极和电解质之间的接触,从而实现Na+和电子的有效传输。在协同作用下,样品NSPC1200表现出优异的储钠能力,在20 mA g^(−1)电流密度下呈现314.2 mAh g^(−1)的可逆容量。即使在100 mA g^(−1)下循环200次,仍保持224.4 mAh g^(−1)的比容量。这项工作成功实现了策略性调整煤基炭材料微观结构的目标,最终获得了具有优异的电化学性能的硬炭阳极。

蛋黄-壳NiCoP@N-C材料的制备及其储钠特性研究

NiCo基磷化物因其优异的导电性和较高的理论容量,被认为是最有潜力的钠离子电极材料.然而,NiCo基磷化物在钠离子嵌入/脱出时会发生严重的体积应变,导致NiCo基磷化物的倍率特性降低,循环稳定性大幅度衰减.针对这些问题,采用多巴胺包覆-煅烧-磷化处理法制备了蛋黄-壳结构的NiCoP@N-C材料,在该材料中,氮掺杂碳层有效地改善了电极材料固有的电导率和结构完整性;独特的蛋黄-壳结构显著减缓了在钠离子嵌入/脱出过程中的体积膨胀.当NiCoP@N-C作为钠离子电池负极材料时表现出优异的电化学性能.在0.1 A·g^(-1)电流密度下,循环100圈后的可逆比容量仍高达462.3 mAh·g^(-1).

UPLC-MS/MS法测定头孢哌酮钠及其制剂中遗传毒性杂质N-亚硝基二甲胺与N-亚硝基二乙胺

目的建立UPLC-MS/MS法测定头孢哌酮钠及其制剂中遗传毒性杂质N-亚硝基二甲胺(NDMA)与N-亚硝基二乙胺(NDEA)的含量。方法采用GL Sciences InertsilTM ODS-3(100 mm×3.0 mm,3μm)色谱柱,流动相A为含0.1%甲酸的水溶液,流动相B为含0.1%甲酸的甲醇溶液,梯度洗脱,流速0.3 mL/min,柱温为35℃;检测方式为正离子(ESI+)模式下选择离子监测(SIM)。结果NDMA在0.5416~270.8 ng/mL范围内线性关系良好,检测限(LOD)与定量限(LOQ)分别为0.008与0.01 ppb,加标回收率为99.3%~107.0%;NDEA在0.1463~73.14 ng/mL范围内线性关系良好,检测限(LOD)与定量限(LOQ)分别为0.001与0.002 ppb,加标回收率为90.0%~96.0%。对7批次原料、66批次制剂与影响因素试验下放置的制剂进行测定,结果3批原料与30批制剂中检出NDMA,所有样品均未检出NDEA;影响因素试验下的制剂NDMA与NDEA均未增加。结论该方法准确、专属性强、灵敏度高,可用于头孢哌酮钠及其制剂中遗传毒性杂质NDMA与NDEA的测定,并建议企业对头孢哌酮钠原料生产工艺进行评估并严格控制。

Cellulose nanofiber-derived carbon aerogel for advanced room-temperature sodium–sulfur batteries

Room-temperature sodium–sulfur(RT/Na–S)batteries are regarded as promising large-scale stationary energy storage systems owing to their high energy density and low cost as well as the earth-abundant reserves of sodium and sulfur.However,the diffusion of polysulfides and sluggish kinetics of conversion reactions are still major challenges for their application.Herein,we developed a powerful and functional separator to inhibit the shuttle effect by coating a lightweight three-dimensional cellulose nanofiber-derived carbon aerogel on a glass fiber separator(denoted NSCA@GF).The hierarchical porous structures,favorable electronic conductivity,and three-dimensional interconnected network of N,S-codoped carbon aerogel endow a multifunctional separator with strong polysulfide anchoring capability and fast reaction kinetics of polysulfide conversion,which can act as the barrier layer and an expanded current collector to increase sulfur utilization.Moreover,the hetero-doped N/S sites are believed to strengthen polysulfide anchoring capability via chemisorption and accelerate the redox kinetics of polysulfide conversion,which is confirmed from experimental and theoretical results.As a result,the assembled Na–S coin cells with the NSCA@GF separator showed a high reversible capacity(788.8 mAh g^(−1) at 0.1 C after 100 cycles)and superior cycling stability(only 0.059%capacity decay per cycle over 1000 cycles at 1 C),thereby demonstrating the significant potential for application in high-performance RT/Na–S batteries.

Solvent extraction and separation of cobalt from leachate of spent lithium-ion battery cathodes with N263 in nitrite media

To effectively separate and recover Co(Ⅱ) from the leachate of spent lithium-ion battery cathodes,we investigated solvent extraction with quaternary ammonium salt N263 in the sodium nitrite system.NO_(2)^(-)combines with Co(Ⅱ) to form an anion [Co(NO_(2))_(3)]^(-),and it is then extracted by N263.The extraction of Co(Ⅱ) is related to the concentration of NO_(2)^(-).The extraction efficiency of Co(Ⅱ) reaches the maximum of99.16%,while the extraction efficiencies of Ni(Ⅱ),Mn(Ⅱ),and Li(Ⅰ) are 9.27%-9.80% under the following conditions:30vol% of N263 and15vol% of iso-propyl alcohol in sulfonated kerosene,the volume ratio of the aqueous-to-organic phase is 2:1,the extraction time is 30 min,and1 M sodium nitrite in 0.1 MHNO_(3).The theoretical stages require for the Co(Ⅱ) extraction are performed in the McCabe–Thiele diagram,and the extraction efficiency of Co(Ⅱ) reaches more than 99.00% after three-stage counter-current extraction with Co(Ⅱ) concentration of 2544mg/L.When the HCl concentration is 1.5 M,the volume ratio of the aqueous-to-organic phase is 1:1,the back-extraction efficiency of Co(Ⅱ)achieves 91.41%.After five extraction and back-extraction cycles,the Co(Ⅱ) extraction efficiency can still reach 93.89%.The Co(Ⅱ) extraction efficiency in the actual leaching solution reaches 100%.

对二氯苯和N-甲基-4-氨基丁酸钠的反应动力学

为了探究对二氯苯(DCB)与N-甲基-4-氨基丁酸钠(SMAB)的反应对聚苯硫醚(PPS)聚合反应的影响,采用动力学方法研究PPS聚合条件下DCB与SMAB的反应。通过分析反应网络、简化反应过程,建立产物N,N′-二甲基-N,N′-(1,4-亚苯基)-4,4′-二氨基二丁酸钠、N,N′-二甲基-N,N′-(1,3-亚苯基)-4,4′-二氨基二丁酸钠(均记为d-SPMAB)、N-甲基-N-(3-氯苯基)-4-氨基丁酸钠(m-SCMAB)、N-甲基-N-(4-氯苯基)-4-氨基丁酸钠(p-SCMAB)和对氯苯酚钠(p-SCP)的生成反应动力学模型;根据质量作用定律、采用稳态假设,推导出各产物的生成反应动力学方程,并运用实验数据进行线性拟合。结果表明:产物d-SPMAB、m-SCMAB、p-SCMAB和p-SCP的生成反应表观活化能分别为168.8、154.5、120.3和131.6 kJ·mol^(-1);增大SMAB与DCB物质的量比可以加快反应,但不改变反应机理;水有利于DCB的水解反应,但溶剂化作用会阻碍DCB与SMAB的取代反应。

不同S/N对硫自养短程反硝化亚硝酸盐积累特性试验研究

短程反硝化是一种厌氧氨氧化基质NO_(2)^(-)-N获取的新型途径。在自养短程反硝化系统中,以硫代硫酸钠作为底物,在不同的硫氮比(S2-/NO_(3)^(-)-N)的条件下,通过控制水力停留时间、温度,将NO_(3)^(-)-N还原至NO_(2)^(-)-N,成功实现自养短程反硝化系统中NO_(2)^(-)-N的积累。实验结果表明,三个S/N表现出不同的NO_(2)^(-)-N的积累,S/N为1:1.14时,NO_(3)^(-)-N的去除率稳定在75%左右,NO_(2)^(-)-N的积累率(NTR)几乎为零;S/N为1:1.71时,NO_(3)^(-)-N的去除率维持在40%~50%之间,NTR增长到8%左右;S/N为1:2.28时,NO_(3)^(-)-N的去除率保持在了35%左右,而NTR持续增长到43%。反硝化速率随S/N的增大而增大,而较低碳氮比更有利于NO_(2)^(-)-N的稳定积累。经高通量测序分析得出,硫自养短程反硝化进程中存在Thioacillus、Thermomonas、Ferritrophicum等所属功能菌种。

沙库巴曲缬沙坦钠与缬沙坦对老年冠心病PCI术后患者心肌酶谱NT-proBNP及炎症因子的影响

目的:对比沙库巴曲缬沙坦钠与缬沙坦对老年冠心病经皮冠状动脉介入(PCI)术后患者心肌酶谱、氨基末端B型钠尿肽前体(NT-proBNP)及炎症因子的影响。方法:回顾性收集我院2020年1月至2022年1月收治的139例老年冠心病PCI术后患者资料,其中40例接受常规治疗(对照组),50例在常规治疗的基础上接受沙库巴曲缬沙坦钠治疗(沙库巴曲缬沙坦钠组),49例在常规治疗的基础上接受缬沙坦治疗(缬沙坦组)。比较各组治疗前、治疗2个月后心功能、心肌酶谱、NT-proBNP及炎症因子[肿瘤坏死因子(TNF)-α,白细胞介素(IL)-6,C反应蛋白(CRP)]水平,同时记录主要不良心脏事件(MACE)发生率。结果:沙库巴曲缬沙坦钠组治疗前后左心室射血分数(LVEF)、左心室收缩末期内径(LVESD)、左心室舒张末期内径(LVEDD)差值均高于缬沙坦组和对照组(P<0.05);沙库巴曲缬沙坦钠组治疗前后肌酸激酶(CK)、肌酸激酶同工酶(CK-MB)、乳酸脱氢酶(LDH),天冬氨酸氨基转移酶(AST)、NT-proBNP、肿瘤坏死因子(TNF)-α、白细胞介素(IL)-6差值均高于缬沙坦组和对照组(P<0.05);沙库巴曲缬沙坦钠组、缬沙坦组和对照组MACE总发生率分别为6.00%、14.29%和27.50%,三组间比较差异有统计学意义(P<0.05)。结论:对于老年冠心病PCI术后患者,相比缬沙坦,采用沙库巴曲缬沙坦钠治疗可改善心功能,使心肌酶谱恢复正常,下调NT-proBNP及炎症因子水平,降低术后MACE发生风险。

S,N共掺杂TiO_(2)纳米管作为钠离子电池负极的储钠性能

合理的结构设计和单原子掺杂可以明显提高二氧化钛(TiO_(2))作为钠离子电池负极的储钠性能。然而单原子掺杂在TiO_(2)中较低的掺杂质量分数与单一的功能作用阻碍了TiO_(2)作为钠离子电池负极电化学性能的进一步增强,因此研究了高质量分数掺杂和双原子掺杂对TiO_(2)储钠性能的影响。通过砂纸打磨对钛箔表面进行预处理除去氧化层,在含有0.56 g的NH_(4)F、5 mL的H_(2)O和95 mL的乙二醇(EG)溶液中,在20 min内通过施加阳极氧化电压60 V,在室温环境下对钛箔进行阳极氧化,在其表面生长出TiO_(2)纳米管阵列;以CH4N2S作为N源和S源,使用退火的方式对TiO_(2)纳米管阵列进行掺杂,得到S,N共掺杂的TiO_(2)纳米管阵列。实验结果表明,S,N共掺杂TiO_(2)的质量分数分别为1.53%和4.76%时,显著提高了TiO_(2)的电导率,加快了钠离子转移动力学。另外,TiO_(2)作为钠离子电池负极表现出强大的倍率性能和长循环性能,在0.1C(1C=335 mA·g^(-1))的电流密度下,S,N共掺杂TiO_(2)电极保持296.6 mA·h·g^(-1)的可逆电荷比容量,在25.0C的电流密度下保持158.1 mA·h·g^(-1)的可逆电荷比容量,并在约3500圈循环后的可逆电荷比容量保持率高达94.8%。相较于单掺杂,双掺杂使掺杂质量分数更高并产生协同效应,该策略为制备出优异性能的电极材料提供了参考。

基于c-Jun氨基末端激酶/p38丝裂原活化蛋白激酶信号通路探讨阿魏酸钠对偏头痛大鼠炎症反应的抑制作用

目的 探讨阿魏酸钠(SF)通过调控JNK/p38 MAPK信号通路对偏头痛大鼠炎症反应的抑制作用。方法 腹腔注射硝酸甘油制备偏头痛大鼠模型,模型制作成功后随机分为模型组、SF低剂量(SF-L)组(50 mg/kg)、 SF高剂量(SF-H)组(100 mg/kg)、SF+JNK抑制剂(SF+SP600125)组(SF 100 mg/kg+SP600125 10 mg/kg)、 SF+JNK激活剂[SF+茴香霉素(AN)]组(SF 100 mg/kg+AN 5 mg/kg),每组12只,另取12只SD大鼠不做处理作为空白组。给药结束24 h后观察各组大鼠行为学变化,ELISA法检测血清中5-羟色胺(5-HT)、一氧化氮(NO)、肿瘤坏死因子α(TNF-α)、白细胞介素6(IL-6)水平,TUNEL染色观察脑组织神经元凋亡情况,免疫组织化学法检测脑组织中TNF-α、 IL-6、降钙素基因相关肽(CGRP)表达,Western blotting法检测脑组织中JNK/p38 MAPK通路相关蛋白的表达。结果 与空白组比较,模型组大鼠挠头次数以及爬笼次数明显增加,神经元凋亡率显著升高;血清5-HT含量显著降低,NO、TNF-α和IL-6水平显著升高;脑组织中TNF-α、IL-6和CGRP表达以及磷酸化JNK(p-JNK)/JNK、磷酸化p38 MAPK(p-p38 MAPK)/p38 MAPK比值均显著升高(均P<0.05)。与模型组比较,SF-L组、SF-H组大鼠挠头次数及爬笼次数显著减少,神经元凋亡率显著降低;血清中5-HT含量显著升高,NO、TNF-α和IL-6水平显著降低;脑组织中TNF-α、IL-6和CGRP表达以及p-JNK/JNK、p-p38 MAPK/p38 MAPK比值均显著降低(均P<0.05)。与SF-H组比较,SF+SP600125组能够显著增强SF对偏头痛大鼠的保护作用;SF+AN组能够显著逆转SF对偏头痛大鼠的保护作用。结论 SF可能通过抑制JNK/p38 MAPK信号通路的表达,有效抑制偏头痛大鼠神经源性炎症反应,减少神经元凋亡,实现对偏头痛大鼠的保护作用。

可见光诱导荧光素钠催化N-芳基四氢异喹啉的交叉脱氢偶联合成THIQs类化合物

1,2,3,4-四氢异喹啉类化合物存在于许多天然产品中,是合成生物活性分子的重要活性中间体,在药物和生物合成中受到广泛应用,同时,在有机合成领域中也具有重要的潜在应用价值。在以2-位芳环上连有不同取代基的N-芳烃四氢异喹啉类化合物(1a~1n)为原料,以12 W蓝色LED灯为光源,荧光素钠为光催化剂,甲醇为溶剂的最佳反应条件下,于室温反应8 h,合成了14个带有不同取代基的2-位(芳基)-1,2,3,4-四氢异喹啉类化合物(2a~2n),产率可达82%~96%,其结构通过^(1)H NMR和^(13)C NMR表征,并分析了反应可能的机理。该方法具有方便高效、环境友好、原子经济和产率较高的特点。

Wet reclamation of sodium silicate used sand and biological treatment of its wastewater by Nitzschia palea

The massive amount of sodium silicate in the used sand was a pollution source, especially in the waste water from the wet reclamation of used sand. A new process of wet reclamation by biologically treating the waste water produced during the wet reclamation process of used sand was studied in the paper. In the work, the precultivation of N. palea was performed firstly, and three different scrubbing solutions： （1） tap water, （2） modified medium for N. palea, and （3） filtrate of the broth treated by N. palea for 15 days, were used. The results of the primary investigation show that a de-skinning ratio of 90% is obtained when using the scrubbing solution containing modified medium for N. palea at the ratio 1：2 of sand and scrubbing solution, and the maximal concentrations of Na^＋ and SiO3^2- are 1.49 g.L-1 and 0.51 g.L-1, respectively. The results of the optimal biomass, pH value decrease and Na^＋ and SiO32 consumption indicate the optimal incubation conditions are at the irradiance of 5,000 lux and 25 ℃. Using the filtrate of the broth treated by N. palea for 15 days as the scrubbing solution directly, a de-skinning ratio of 93% is the highest compared to the results of the tap water and the modified medium for N. palea. In the biological process using N. palea, less water is used and little wastewater is produced, which is advantageous to the purpose of green manufacturing and environmental protection.

Enhanced photocatalytic Cr(Ⅵ) reduction and diclofenac sodium degradation under simulated sunlight irradiation over MIL-100(Fe)/g-C_3N_4 heterojunctions

Metal‐organic framework MIL‐100(Fe)and g‐C3N4 heterojunctions(MG‐x,x=5%,10%,20%,and 30%,x is the mass fraction of MIL‐100(Fe)in the hybrids)were facilely fabricated through ball‐milling and annealing,and characterized by powder X‐ray diffraction,Fourier transform infrared spectroscopy,thermogravimetric analysis,transmission electron microscopy,UV‐visible diffuse‐reflectance spectrometry,and photoluminescence emission spectrometry.The photocatalytic activities of the series of MG‐x heterojunctions toward Cr(VI)reduction and diclofenac sodium degradation were tested upon irradiation with simulated sunlight.The influence of different organic compounds(ethanol,citric acid,oxalic acid,and diclofenac sodium)as hole scavengers and the pH values(2,3,4,6,and 8)on the photocatalytic activities of the series of MG‐x heterojunctions was investigated.MG‐20%showed superior photocatalytic Cr(VI)reduction and diclofenac sodium degradation performance than did the individual MIL‐100(Fe)and g‐C3N4 because of the improved separation of photoinduced electron‐hole charges,which was clarified via photoluminescence emission and electrochemical data.Moreover,the MG‐x exhibited good reusability and stability after several runs.

单层Si_(3)N作为钠/钾离子电池的高容量阳极材料的可行性研究

采用密度泛函理论(DFT)研究了二维单层Si_(3)N作为离子电池阳极材料的相关性能.零带隙能带结构表明,单层Si_(3)N具有金属特性,金属的高导电能力有利于其作为阳极材料.计算结果表明,单层Si_(3)N对于钠和钾的理论容量分别为1230 mAh∙g^(-1)和889 mAh∙g^(-1).与此同时,该材料对钠和钾的理论能量密度分别为1090 mWh∙g^(-1)和576 mWh∙g^(-1),高于之前一些报道的二维阳极材料.此外,钠、钾原子在单层Si_(3)N上的扩散势垒分别为0.30,0.38 eV,表明该材料具有非常高的充放电速率,且在吸附过程中,Si_(3)N一直保持着良好的金属特性和结构完整性,这些性质使其具有良好的电池工作循环性能.以上结果表明,单层Si_(3)N是理想的钠/钾离子电池阳极材料.

气相色谱法检测溴芬酸钠中N-亚硝基二甲胺

采用气相色谱法,建立了溴芬酸钠原料药中基因毒性杂质N-亚硝基二甲胺(NDMA)含量的检测方法。采用Agilent DB-WAX气相色谱柱、氢火焰离子化检测器,液体进样,按外标法测定溴芬酸钠原料药中的NDMA含量。结果表明,NDMA在0.491~24.545μg/mL范围内线性关系良好,定量限(LOQ)为0.48μg/mL,检测限(LOD)为0.24μg/mL;准确度实验回收率为92.4%~104.9%,平均回收率为100.9%,RSD(n=9)为4.4%。该方法操作简单,能够有效地检测溴芬酸钠原料药中NDMA的含量。

From Jackfruit Rags to Hierarchical Porous N-Doped Carbon: A High-Performance Anode Material for Sodium-Ion Batteries

Renewable biomass-derived carbon materials have attracted increasing research attention as promising electrode materials for electrochemical energy storage devices, such as sodium-ion batteries (SIBs), due to their outstanding electrical conductivity, hierarchical porous structure, intrinsic heteroatom doping, and environmental friendliness. Here, we investigate the potential of hierarchical N-doped porous carbon (NPC) derived from jackfruit rags through a facile pyrolysis as an anode material for SIBs. The cycling performance of NPC at 1 A/g for 2000 cycles featured a stable reversible capacity of 122.3 mA h/g with an outstanding capacity retention of 99.1%. These excellent electrochemical properties can be attributed to the unique structure of NPC;it features hierarchical porosity with abundant carbon edge defects and large speci c surface areas. These results illuminate the potential application of jackfruit rags-derived porous carbon in SIBs.

木质素基N,S-CQDs的制备及其在Fe^(3+)检测中的应用

以木质素磺酸钠为碳源和硫源,低共熔溶剂(DES)为氮源和反应溶剂制备了一种氮、硫双掺杂的碳量子点(N,S-CQDs)。制备的N,S-CQDs的粒径分布均匀,平均粒径为4.95 nm,量子产率达到了35.7%,量子产率大幅提升。制备的N,S-CQDs对Fe^(3+)具有优异的敏感性,可用于Fe^(3+)的定量检测,检测限为0.25μmol·L^(-1),检测范围是0~200μmol·L^(-1)。

Activity of NaOH in Sodium Aluminate Solutions

1.IntroductionSodium aluminate solution is one of themost important intermediate products in al-uminium metallurgy.The structure of so-dium aluminate solutions is rather compli-cated.Various anionic species,includingAl（OH）;,Al（OH）;and[（OH）;-Al-O-Al（OH）;];are co-existent in sodiumaluminate solutions.Using Raman and

N-氨乙基哌嗪与甘氨酸钠CO_(2)吸收剂配方研究

化学吸收法是捕集燃煤电厂烟气中CO_(2)应用最为广泛的技术之一,但其存在吸收容量较低及再生能耗较高等问题,因此开发新型高效CO_(2)吸收剂代替传统单乙醇胺(MEA)吸收剂是当前研究的重点之一。以质量分数为30%的MEA作为参考标准,研究不同配比的N-氨乙基哌嗪(AEP)+甘氨酸钠(SG)复配溶液对CO_(2)的吸收和解吸性能,通过添加不同助剂调节溶液pH值提高吸收剂再生性能,通过对比吸收剂的吸收量、吸收速率、解吸量、解吸速率、吸收-解吸循环性能以及再生能耗,优选出35%AEP+5%SG+1%柠檬酸为最优复配吸收剂。结果表明,配比为35%AEP+5%SG+1%柠檬酸吸收剂CO_(2)吸收量3.70mol/L,解吸量为3.55mol/L,解吸率达96.05%,单位再生能耗为136.75 kJ/mol,与质量分数30%MEA相比,吸收量提高1.18倍,解吸量增加2.17倍,解吸率提高30.93%,再生能耗下降33.90%。经过10次循环试验后,该复配溶液循环稳定性良好,再生性能较优,具有潜在的应用价值。