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1.
芳甲酸氰基芳甲酯是重要的有机合成中间体,其现有合成方法采用剧毒氰化物为氰源来合成。 本研究以K4[Fe(CN)6]为绿色氰化试剂,芳酰氯为原料,采用一锅两步反应合成芳甲酸氰基芳甲酯。 通过改变第二步反应温度、反应时间、硼氢化钠和催化剂的用量获得最佳反应条件,以61.7%~80.3%的产率合成了10种芳甲酸氰基芳甲酯(2a~2j),产物结构通过傅里叶变换红外光谱仪(FTIR)、核磁共振波谱仪(NMR)分析确认。 根据实验结果,提出了可能的反应机理。 该法避免了对剧毒氰化剂的使用,具有产率高、操作简单、后处理方便等优点。  相似文献   

2.
吴雯  侯孟炎  周丹丹  夏永姚 《电化学》2011,17(2):169-174
合成5种孔径大小分布的NiO样品,测定各NiO电极在3mol/L KOH或其添加K3[Fe(CN)6]的电解液中的电化学电容性能.结果表明,NiO电极孔径分布在15nm左右,可有效减慢铁氰酸根离子向液相的扩散,从而提高N4 (NiO)电极的充放电效率.  相似文献   

3.
在pH 2~3的溶液中,低浓度Fe^2+与K3[Fe(CN)6]反应产生的蓝色沉淀为近似真溶液,最大吸收波长为710 nm.形成的近似真溶液吸光度随静置时间变化而逐渐变大,30 min后吸光度变化缓慢.K3[Fe(CN)6]过量时,Fe^2+浓度与吸光度呈很好的线性关系.Fe^2+浓度较大时,易形成絮状沉淀.在pH 2~3的Fe^3+-K3[Fe(CN)6]体系中,加入Vc能将Fe^3+还原成Fe^2+,进而与K3[Fe(CN)6]反应,30 min后测定蓝色拟真溶液的吸光度,Vc的量与溶液的吸光度同样有很好的线性关系,线性相关系数R〉0.999,检出限为0.94μg.  相似文献   

4.
在pH 6.5的弱酸性条件下,盐酸丙咪嗪(IPH)能将Fe3+还原为Fe2+,根据Fe2+与K3[Fe(CN)6]反应生成可溶性的普鲁士蓝(Fe3[Fe(CN)6]2),使体系的共振瑞利散射强度显著增强,可以间接测定盐酸丙咪嗪的含量。据此建立了共振瑞利散射法测定盐酸丙咪嗪含量的新方法。盐酸丙咪嗪在0.04~3.50 mg/L范围内与共振瑞利散射强度增加值呈良好的线性关系,检出限为0.034 mg/L。考察了体系的共振瑞利散射光谱、紫外-可见吸收光谱特征,研究了适宜的反应条件以及共存物质的影响。该方法用于盐酸丙咪嗪片剂和尿样中盐酸丙咪嗪含量的测定,回收率在97.8%~103.3%之间。  相似文献   

5.
本文研究了K4[Fe(CN)6]掺杂对溴碘化银T-颗粒乳剂感光性能的影响.结果表明,掺杂剂的掺杂量以及掺杂位置对乳剂的感光性能都有影响.K4[Fe(CN)6]的掺杂量在每克乳剂31×10-9-31×10-11mol之间时,乳剂感光度都有提高.最佳掺杂量为每克乳剂31×10-10mol.掺杂位置接近表面时效果相对较好,表明K4[Fe(CN)6]是浅电子陷阱掺杂剂.当掺杂剂的掺杂量大于每克乳剂31×10-8mol,且掺杂位置在乳剂颗粒较深内部时,乳剂的感光度反而下降.  相似文献   

6.
以邻氯溴苯为起始原料,选用K4[Fe(CN)6]为氰基化试剂,Pd/C催化反应制得邻氯苯甲腈。 考察了温度、碱、催化剂的用量和原料比等对反应的影响,确定了较佳反应条件。 邻氯溴苯转化率达98.5%,产物邻氯苯甲腈得率95.1%。  相似文献   

7.
MOFs材料作为一类新型的锂离子电池电极材料而受到广泛关注和研究. 作者通过溶液扩散法将Co3(HCOO)6原位负载在 rGO(还原氧化石墨烯)上制备出Co3(HCOO)6@rGO复合材料. 将Co3(HCOO)6@rGO作为锂离子电池负极材料,以500 mA·g-1的电流密度恒电流充放电循环 100 周后,仍然保持有 926 mAh·g-1 的比容量,亦表现出很好的倍率性能. 循环伏安和X-射线光电子能谱测试表明,Co3(HCOO)6@rGO材料上的Co2+和甲酸根在充放电过程中均发生可逆的电化学反应. 对比同样采用溶液扩散法合成的 Co3(HCOO)6 的测试结果发现,rGO起到活化甲酸根的电化学反应的作用,同时也改善了Co3(HCOO)6的倍率性能. 将MOFs材料与rGO复合为优化 MOFs 材料的电池性能提供了一个新思路.  相似文献   

8.
水系钠离子电池具有钠资源丰富、成本低廉、安全可靠、维护简单等特点,在可再生能源规模储存领域具有重要应用前景。NASICON型NaTi2(PO4)3具有可逆容量高、工作电位低、离子传输快等优点,是目前最受关注的水系钠离子电池负极材料。但是,该材料在传统的水系电解液中结构不稳定,循环性能不足。本论文通过调控Na2SO4浓度和引入MgSO4添加剂,构建了一种新型硫酸盐功能电解液(2 mol·L-1 Na2SO4 + 0.3 mol·L-1 MgSO4)。该电解液能够显著增强NaTi2(PO4)3/C材料在充放电循环过程中的结构稳定性,从而提高其电化学可逆性和稳定性。电化学测试表明,NaTi2(PO4)3/C基于该电解液在100 mA·g-1条件下的可逆容量为93.4 mAh·g-1,循环100次后容量保持率高达96.5%;基于该电解液构建的Na2Ni[Fe(CN)6]|NaTi2(PO4)3/C电池可以稳定循环500次以上。本论文结合XRD、XPS等技术讨论分析了该电解液的功能作用机制,其研究结果为设计低成本高性能水系钠离子电池提供了新思路和实验基础。  相似文献   

9.
采用共沉淀法将氢氧化镧(La(OH)3)负载在锌铝水滑石(Zn-Al LDHs)的表面,扫描电镜(SEM)、X射线衍射(XRD)表明La(OH)3成功负载在锌铝水滑石表面,并且负载后的锌铝水滑石仍然为六边形片状晶体,且粒径均匀、分散性好。La(OH)3质量其具有较好的可逆性、更大的正腐蚀电位及较小的电池内阻。5%La(OH)3@Zn-Al LDHs在经过80次循环后,其循环保持率为94.84%。  相似文献   

10.
研制了光导纤维光谱电化学池(FOSECC),并用该池研究Fe(CN)63-/Fe(CN)64-一氧化还原体系。获得不同电位下的吸收光谱;在不同温度下分别测定了式量电位E°′和反应得失电子数n;求出了体系电极反应的△H°和△S°;计算了FOSECC的灵敏度--摩尔吸收/电位比,结果满意。  相似文献   

11.
In view of the continuously worsening environmental problems, fossil fuels will not be able to support the development of human life in the future. Hence, it is of great importance to work on the efficient utilization of cleaner energy resources. In this case, cheap, reliable, and eco-friendly grid-scale energy storage systems can play a key role in optimizing our energy usage. When compared with lithium-ion and lead-acid batteries, the excellent safety, environmental benignity, and low toxicity of aqueous Zn-based batteries make them competitive in the context of large-scale energy storage. Among the various Zn-based batteries, due to a high open-circuit voltage and excellent rate performance, Zn-Ni batteries have great potential in practical applications. Nevertheless, the intrinsic obstacles associated with the use of Zn anodes in alkaline electrolytes, such as dendrite, shape change, passivation, and corrosion, limit their commercial application. Hence, we have focused our current efforts on inhibiting the corrosion and dissolution of Zn species. Based on a previous study from our research group, the failure of the Zn-Ni battery was caused by the shape change of the Zn anode, which stemmed from the dissolution of Zn and uneven current distribution on the anode. Therefore, for the current study, we selected K3[Fe(CN)6] as an electrolyte additive that would help minimize the corrosion and dissolution of the Zn anode. In the alkaline electrolyte, [Fe(CN)6]3– was reduced to [Fe(CN)6]4– by the metallic Zn present in the Zn-Ni battery. Owing to its low solubility in the electrolyte, K4[Fe(CN)6] adhered to the active Zn anode, thereby inhibiting the aggregation and corrosion of Zn. Ultimately, the shape change of the anode was effectively eliminated, which improved the cycling life of the Zn-Ni battery by more than three times (i.e., from 124 cycles to more than 423 cycles). As for capacity retention, the Zn-Ni battery with the pristine electrolyte only exhibited 40% capacity retention after 85 cycles, while the Zn-Ni battery with the modified electrolyte (i.e., containing K3[Fe(CN)6]) showed 72% capacity retention. Moreover, unlike conventional organic additives that increase electrode polarization, the addition of K3[Fe(CN)6] not only significantly reduced the charge-transfer resistance in a simplified three-electrode system, but also improved the discharge capacity and rate performance of the Zn-Ni battery. Importantly, considering that this strategy was easy to achieve and minimized additional costs, K3[Fe(CN)6], as an electrolyte additive with almost no negative effect, has tremendous potential in commercial Zn-Ni batteries.  相似文献   

12.
采用聚二烯丙基二甲基氯化铵(PDDA)将铁氰化钾电子媒介体固定在电极表面,构建免标记的电化学免疫传感器. 醛基吡啶盐不仅作为基底物质直接固定抗体,还可以很好地增强电极表面的导电性能. 将构建的传感器用于肿瘤标志物甲胎蛋白的检测. 其线性范围为0.01-20 ng·mL-1,检测下限为0.004 ng·mL-1(3 S/N). 此传感器的构建简单方便、无标记、特异性好,为甲胎蛋白及其他肿瘤标志物提供了新的检测方法.  相似文献   

13.
Aqueous redox flow batteries (ARFBs) are a promising technology for grid-scale energy storage, however, their commercial success relies on redox-active materials (RAM) with high electron storage capacity and cost competitiveness. Herein, a redox-active material lithium ferrocyanide (Li4[Fe(CN)6]) is designed. Li+ ions not only greatly boost the solubility of [Fe(CN)6]4− to 2.32 M at room temperature due to weak intermolecular interactions, but also improves the electrochemical performance of [Fe(CN)6]4−/3−. By coupling with Zn, ZIRFBs were built, and the capacity of the batteries was as high as 61.64 Ah L−1 (pH-neutral) and 56.28 Ah L−1 (alkaline) at a [Fe(CN)6]4− concentration of 2.30 M and 2.10 M. These represent unprecedentedly high [Fe(CN)6]4− concentrations and battery energy densities reported to date. Moreover, benefiting from the low cost of Li4[Fe(CN)6], the overall chemical cost of alkaline ZIRFB is as low as $11 per kWh, which is one-twentieth that of the state-of-the-art VFB ($211.54 per kWh). This work breaks through the limitations of traditional electrolyte composition optimization and will strongly promote the development of economical [Fe(CN)6]4−/3−-based RFBs in the future.  相似文献   

14.
Duan H  Liu Z  Liu S  Yi A 《Talanta》2008,75(5):1253-1259
Under the HCl solution and heating condition, penicillin antibiotics such as amoxicillin (AMO), ampicillin (AMP), sodium cloxacillin (CLO), sodium carbenicillin (CAR) and sodium benzylpenicillin (BEN) could react with Fe(III) to produce Fe(II) which further reacted with Fe(CN)63− to form a Fe3[Fe(CN)6]2 complex. By virtue of hydrophobic force and Van der Waals force, the complex aggregated to form Fe3[Fe(CN)6]2 nanoparticles with an average diameter of 45 nm. This resulted in a significant enhancement of resonance Rayleigh scattering (RRS) and non-linear scattering such as second-order scattering (SOS) and frequency doubling scattering (FDS). The increments of scattering intensity (ΔI) were directly proportional to the concentrations of the antibiotics in a certain range. The detection limits for the five penicillin antibiotics were 2.9–6.1 ng ml−1 for RRS method, 4.0–6.8 ng ml−1 for SOS method and 7.4–16.2 ng ml−1 for FDS method, respectively. Among them, the RRS method exhibited the highest sensitivity and the AMO system was more sensitive than other antibiotics systems. Based on the above researches, a new highly sensitive and simple method for the indirect determination of penicillin antibiotics has been developed. It can be applied to the determination of penicillin antibiotics in capsule, tablet, human serum and urine samples. In this work, the spectral characteristics of absorption, RRS, SOS and FDS spectra, the optimum conditions of the reaction and the influencing factors were investigated. In addition, the reaction mechanism was discussed.  相似文献   

15.
采用不同质量分数的NH_4NO_3和(NH_4)_2S_2O_8溶液作为电解液,对双室微生物燃料电池的阳极炭布进行改性。以餐厨废水作为阳极底物,以K_3[Fe(CN)_6]和NaCl混合溶液为阴极液,考察不同电解液改性阳极条件下微生物燃料电池的产电性能及污水处理效果。结果表明,采用NH_4NO_3或(NH_4)_2S_2O_8改性炭布作为阳极的微生物燃料电池的发电性能和水处理效果均有改善。其中,采用质量分数为4%的(NH_4)_2S_2O_8溶液作为阳极改性电解液时,微生物燃料电池系统的产电性能达到最佳,其稳态电流密度约为60 m A/m~2,COD去除率约为42.5%。  相似文献   

16.
以纸浆为原料制备得到一种粘胶液,经静置水化交联,得到一种纤维素凝胶电解质(XWD-NaOH);添加亚铁氰化钾,使获得的新型纤维素凝胶电解质(XWD-NaOH-K 4[Fe(CN)6])呈现良好的氧化还原活性,电导率达15.3 mS/cm;与XWD-NaOH相比,XWD-NaOH-K 4[Fe(CN)6]电解质超级电容器,在0.5 A/g电流密度下,比电容、功率密度和能量密度分别提高了57%、111%和214%,并且体系具有更低的内阻、电荷转移电阻及高的循环稳定性。  相似文献   

17.
The radiation chemical analogue of the light induced formation of Turnbull blue, K[Fe(II)Fe(III)(CN)6], from K3[Fe(III)(oxalate)3] and K3[Fe(III)(CN)6] was investigated by pulse radiolysis. The kinetic analysis revealed a two-step process: after a pseudo-first order reaction an autocatalytic formation of Turnbull blue takes place. The rate coefficient of the first step is k8=1.42×105 M−1 s−1. The incubation time of precipitation was also determined.  相似文献   

18.
Mossbauer spectroscopy has been applied to the investigation of reaction of Sn[Fe(CN)6] on magnesia, 7-alumina, silica and activated carbon. It was found that the thermal decomposition products of supported Sn[Fe(CN)6] are quite different from those of the unsupported one as a result of the interaction between the complex and supports. The supports could promote the oxidation in the air atmosphere and their effect led to high dispersion of the decomposition products on the surface.  相似文献   

19.
锂硫电池具有理论能量密度高、环境友好和成本低等优点,有望成为替代锂离子电池的新一代储能系统。然而,锂硫电池充放电产物的绝缘性、可溶性多硫化锂的穿梭效应、硫正极体积膨胀及锂枝晶的不可控生长,严重影响了锂硫电池的实际容量发挥和循环稳定性。为解决上述问题,采用有机硫化合物来替代单质硫作为正极材料是有前途的策略。调控有机硫化合物的硫链、碳链及其相互作用,可改变其电化学反应过程,提高离子/电子电导,抑制穿梭效应。有机硫化合物作为电解液添加剂,可调控硫正极的反应过程并保护金属锂负极,作为聚合物电解质的改性链段可加速锂离子传导。本综述对有机硫化合物在锂硫电池的正极、电解液添加剂和固态电解质中的应用研究进展进行详细的阐述。将有机硫化合物的结构、反应机理和电化学性质联系起来,为解决锂硫电池存在的问题提供见解。最后,提出高性能有机硫化合物的设计合成和机理研究思路,以期实现可实用化的锂硫电池。  相似文献   

20.
中性/弱酸性水系锌锰电池因其能量密度高、价格低廉、环境友好等优势受到广泛关注。然而,现有的二氧化锰正极材料存在导电性能差,在充放电过程中易于溶解等问题。这严重影响了电池的倍率性能和循环稳定性,阻碍了中性锌锰电池的应用。为了解决上述问题,本文设计了以碳纳米管(CNT)网络薄膜为导电基底沉积聚吡咯(PPy)包覆二氧化锰(PPy@MnO2/CNT)的多级结构电极。碳纳米管和聚吡咯组装形成高比表面积的三维交联导电网络,为活性材料提供了快速的电子、离子传输通道;聚吡咯包覆纳米级二氧化锰能够有效地抑制二氧化锰的溶解,进而提升电池的倍率特性和循环稳定性。以PPy@MnO2/CNT作为正极材料组装的水系锌锰电池在1 A·g-1的电流密度下,比容量达到210 mAh·g-1,循环1000圈后,电池依然具有较高的容量保持率(85.7%)。本工作的导电聚合物包覆活性物质的策略可为发展高稳定柔性储能器件提供新思路。  相似文献   

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