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1.
A facile one-step strategy involving the reaction of antimony chloride with thioacetamide at room temperature is successfully developed for the synthesis of strongly coupled amorphous Sb2S3 spheres and carbon nanotubes (CNTs). Benefiting from the unique amorphous structure and its strongly coupled effect with the conductive network of CNTs, this hybrid electrode (Sb2S3@CNTs) exhibits remarkable sodium and lithium storage properties with high capacity, good cyclability, and prominent rate capability. For sodium storage, a high capacity of 814 mAh·g?1 at 50 mA·g?1 is delivered by the electrode, and a capacity of 732 mAh·g?1 can still be obtained after 110 cycles. Even up to 2000 mA·g?1, a specific capacity of 584 mAh·g?1 can be achieved. For lithium storage, the electrode exhibits high capacities of 1136 and 704 mAh·g?1 at 100 and 2000 mA·g?1, respectively. Moreover, the cell holds a capacity of 1104 mAh·g?1 under 100 mA·g?1 over 110 cycles. Simple preparation and remarkable electrochemical properties make the Sb2S3@CNTs electrode a promising anode for both sodium-ion (SIBs) and lithium-ion batteries (LIBs).  相似文献   

2.
Monoclinic SrAl2Si2O8 ceramics for Sr immobilization were prepared by a liquid-phase sintering method. The sintering temperature, mineral phase composition, microstructure, flexural strength, bulk density, and Sr ion leaching characteristics of the SrAl2Si2O8 ceramics were investigated. A crystalline monoclinic SrAl2Si2O8 phase formed through liquid-phase sintering at 1223 K. The introduction of four flux agents (B2O3, CaO·2B2O3, SrO·2B2O3, and BaO·2B2O3) to the SrAl2Si2O8 ceramics not only reduced the densification temperature and decreased the volatilization of Sr during high-temperature sintering but also impacted the mechanical properties of the ceramics. Product consistency tests showed that the leaching concentration of Sr ions in the sample with flux agent B2O3 was the lowest, whereas that of Sr ions in the sample with flux agent BaO·2B2O3 was the highest. These results show that the leaching concentration of Sr ions depends largely on the amorphous phase in the ceramics. Meanwhile, the formation of mineral analog ceramics containing Sr is an important factor to improve Sr immobilization.  相似文献   

3.
The oxidation of oxygen ions and the generation of an anode effect at a low oxygen content of 150 mg/kg were discussed in this paper. Cyclic voltammetry and square-wave voltammetry tests were conducted to explore the anodic processes of LiF–NdF3 melt after a lengthy period of pre-electrolysis purification at 1000°C (during which the oxygen content reduced from 413 to 150 mg/kg). The oxidation process of oxygen ions was found to have two stages: oxidation product adsorption and CO/CO2 gas evolution. The adsorption stage was controlled by diffusion, whereas the gas evolution was controlled by the electrochemical reaction. In comparison with oxygen content of 413 mg/kg, the decrease in the amplitude of the current at low oxygen content of 150 mg/kg was much gentler during the forward scanning process when the anode effect occurred. Fluorine-ion oxidation peaks that occurred at about 4.2 V vs. Li/Li+ could be clearly observed in the reverse scanning processes, in which fluorine ions were oxidized and perfluorocarbons were produced, which resulted in an anode effect.  相似文献   

4.
A near eutectic Al?12.6Si alloy was developed with 0.0wt%, 2.0wt%, 4.0wt%, and 6.0wt% Al?5Ti?1B master alloy. The microstructural morphology, hardness, tensile strength, elongation, and fracture behaviour of the alloys were studied. The unmodified Al?12.6Si alloy has an irregular needle and plate-like eutectic silicon (ESi) and coarse polygonal primary silicon (PSi) particles in the matrix-like α-Al phase. The PSi, ESi, and α-Al morphology and volume fraction were changed due to the addition of the Al?5Ti?1B master alloy. The hardness, UTS, and elongation improved due to the microstructural modification. Nano-sized in-situ Al3Ti particles and ex-situ TiB2 particles caused the microstructural modification. The fracture images of the developed alloys exhibit a ductile and brittle mode of fracture at the same time. The Al?5Ti?1B modified alloys have a more ductile mode of fracture and more dimples compared to the unmodified alloy.  相似文献   

5.
Wood-based panels containing urea-formaldehyde resin result in the long-term release of formaldehyde and threaten human health. In this study, inorganic aluminosilicate coatings prepared by combining metakaolin, silica fume, NaOH, and H2O were applied to the surfaces of wood-based panels to obstruct formaldehyde release. The Si/Al, Na/Al, and H2O/Na2O molar ratios of the coatings were regulated to investigate their effects on the structure and formaldehyde-resistant barrier properties of coatings. Results showed that the cracks in the coatings gradually disappeared and the formaldehyde resistance rates of the barrier increased as the Si/Al molar ratio was increased from 1.6 to 2.2. This value also increased as the Na/Al molar ratio was increased from 0.9 to 1.2 because of the improvement of the degree of polymerization. As the H2O/Na2O molar ratio was increased from 12 to 15, the thickness of the dry film decreased gradually and led to the reduction in the formaldehyde resistance rate. When the Si/Al, Na/Al, and H2O/Na2O molar ratios were 2.2, 1.2, and 12, respectively, the inorganic aluminosilicate coating showed good performance as a formaldehyde-resistant barrier and its formaldehyde resistance rate could reach up to 83.2%.  相似文献   

6.
Pt/CeO2–C catalysts with CeO2 pre-calcined at 300–600°C were synthesized by combining hydrothermal calcination and wet impregnation. The effects of the pre-calcined CeO2 on the performance of Pt/CeO2–C catalysts in methanol oxidation were investigated. The Pt/CeO2–C catalysts with pre-calcined CeO2 at 300–600°C showed an average particle size of 2.6–2.9 nm and exhibited better methanol electro-oxidation catalytic activity than the commercial Pt/C catalyst. In specific, the Pt/CeO2–C catalysts with pre-calcined CeO2 at 400°C displayed the highest electrochemical surface area value of 68.14 m2·g?1 and If/Ib ratio (the ratio of the forward scanning peak current density (If) and the backward scanning peak current density (Ib)) of 1.26, which are considerably larger than those (53.23 m2·g?1 and 0.79, respectively) of the commercial Pt/C catalyst, implying greatly enhanced CO tolerance.  相似文献   

7.
The presence of silver ions (Ag(I)) in wastewater has a detrimental effect on living organisms. Removal of soluble silver, especially at low concentrations, is challenging. This paper presents the use of β-MnO2 particles as a photocatalyst to remove Ag(I) ions selectively from aqueous solution at various pH levels. Inductively coupled plasma mass spectrometry (ICP-MS), X-ray diffraction (XRD), field emission electron microscope (FESEM), transmission electron microscopy (TEM), and X-ray photoelectron microscopy (XPS) were employed to determine the removal efficiency and to characterize the deposition of silver onto the surface of β-MnO2 particles. The optimum pH for the removal of Ag(I) ions was at pH 4 with 99% removal efficiency under 1 h of visible light irradiation. This phenomenon can be attributed to the electrostatic attraction between β-MnO2 particles and Ag(I) ions as well as the suppression of electron–hole recombination in the presence of H+ ions.  相似文献   

8.
We successfully constructed TiO2-pillared multilayer graphene nanocomposites (T-MLGs) via a facile method as follows: dodecanediamine pre-pillaring, ion exchange (Ti4+ pillaring), and interlayer in-situ formation of TiO2 by hydrothermal method. TiO2 nanoparticles were distributed uniformly on the graphene interlayer. The special structure combined the advantages of graphene and TiO2 nanoparticles. As a result, T-MLGs with 64.3wt% TiO2 showed the optimum photodegradation rate and adsorption capabilities toward ciprofloxacin. The photodegradation rate of T-MLGs with 64.3wt% TiO2 was 78% under light-emitting diode light irradiation for 150 min. Meanwhile, the pseudo-first-order rate constant of T-MLGs with 64.3wt% TiO2 was 3.89 times than that of pristine TiO2. The composites also exhibited high stability and reusability after five consecutive photocatalytic tests. This work provides a facile method to synthesize semiconductor-pillared graphene nanocomposites by replacing TiO2 nanoparticles with other nanoparticles and a feasible means for sustainable utilization of photocatalysts in wastewater control.  相似文献   

9.
To improve the sulfur loading capacity of lithium-sulfur batteries (Li–S batteries) cathode and avoid the inevitable “shuttle effect”, hollow N doped carbon coated CoO/SnO2 (CoO/SnO2@NC) composite has been designed and prepared by a hydrothermal-calcination method. The specific surface area of CoO/SnO2@NC composite is 85.464 m2·g–1, and the pore volume is 0.1189 cm3·g–1. The hollow core-shell structure as a carrier has a sulfur loading amount of 66.10%. The initial specific capacity of the assembled Li–S batteries is 395.7 mAh·g–1 at 0.2 C, which maintains 302.7 mAh·g–1 after 400 cycles. When the rate increases to 2.5 C, the specific capacity still has 221.2 mAh·g–1. The excellent lithium storage performance is attributed to the core-shell structure with high specific surface area and porosity. This structure effectively increases the sulfur loading, enhances the chemical adsorption of lithium polysulfides, and reduces direct contact between CoO/SnO2 and the electrolyte.  相似文献   

10.
In this study, we prepared Ti/IrO2–ZrO2 electrodes with different ZrO2 contents using zirconium-n-butoxide (C16H36O4Zr) and chloroiridic acid (H2IrCl6) via a sol–gel route. To explore the effect of ZrO2 content on the surface properties and electrochemical behavior of electrodes, we performed physical characterizations and electrochemical measurements. The obtained results revealed that the binary oxide coating was composed of rutile IrO2, amorphous ZrO2, and an IrO2–ZrO2 solid solution. The IrO2–ZrO2 binary oxide coatings exhibited cracked structures with flat regions. A slight incorporation of ZrO2 promoted the crystallization of the active component IrO2. However, the crystallization of IrO2 was hindered when the added ZrO2 content was greater than 30at%. The appropriate incorporation of ZrO2 enhanced the electrocatalytic performance of the pure IrO2 coating. The Ti/70at%IrO2–30at%ZrO2 electrode, with its large active surface area, improved electrocatalytic activity, long service lifetime, and especially, lower cost, is the most effective for promoting oxygen evolution in sulfuric acid solution.  相似文献   

11.
We report the electrochemical performance of Ni(OH)_2 on a gas diffusion layer(GDL). The Ni(OH)_2 working electrode was successfully prepared via a simple method, and its electrochemical performance in 1 M NaOH electrolyte was investigated. The electrochemical results showed that the Ni(OH)_2/GDL provided the maximum specific capacitance value(418.11 F·g~(-1)) at 1 A·g~(-1). Furthermore, the Ni(OH)_2 electrode delivered a high specific energy of 17.25 Wh·kg~(-1) at a specific power of 272.5 W·kg~(-1) and retained about 81% of the capacitance after 1000 cycles of galvanostatic charge–discharge(GCD) measurements. The results of scanning electron microscopy(SEM) coupled with energy-dispersive X-ray spectroscopy(EDS) revealed the occurrence of sodium deposition after long-time cycling, which caused the reduction in the specific capacitance. This study results suggest that the light-weight GDL, which can help overcome the problem of the oxide layer on metal–foam substrates, is a promising current collector to be used with Ni-based electroactive materials for energy storage applications.  相似文献   

12.
以尿素和氯化镍为原料,采用水热法制备了泡沫镍载Ni(OH)2纳米片电极,利用扫描电镜(SEM)观测了纳米片的形貌,利用X-射线衍射(XRD)分析了纳米片的结构,通过循环伏安和恒流充放电测试了电极的超级电容性能.检测结果表明:所制备的Ni(OH)2纳米片先构成一种交错连接的线状结构,再以线的形式均匀而密集地覆盖在泡沫镍的骨架上.这种特殊结构使得该纳米片电极表现出良好的电容性能,在电流密度为10mA/cm2的情况下,其面积比电容为255mF/cm2.  相似文献   

13.
通过XRD和循环伏安法研究了添加钙对氢氧化镍结构和电化学性能的影响。其中钙是以离子的形式对氢氧化镍掺杂。结果表明:添加了钙的氢氧化镍的晶粒尺寸变小,比表面积增加,晶体缺陷和畸变增多,提高了质子的传递能力和活性物质的利用率,其中以共沉淀方式添加1%钙的氢氧化镍电极的电化学性能最佳。  相似文献   

14.
高铁酸钠的电化学合成研究   总被引:3,自引:2,他引:3  
以金属铁为正极材料、铂为负极,18mol/L NaOH氢氧化钠溶液为电解液在隔膜电解池中电化学合成高铁酸钠。理想合成温度约20℃,电流密度约O.5mA/cm^2,在饱和氢氧化钠溶液中合成电流效率为71.4%。充电电压为1.92—1.83V;电化学合成时间为2-3h。  相似文献   

15.
球形Ni(OH)2包覆钴化合物的积分进料工艺   总被引:4,自引:0,他引:4  
为提高镍电极活性材料之间的导电性,在电极制作过程中需添加适量的导电剂,通过混合式工艺添加的导电剂,其利用率和分布均匀性受工艺条件的限制,得不到可靠的保证。提出了一种积分进料的工艺方法,在球形Ni(OH)2的表面包覆上了一层钴的化合物;并利用扫描电子显微技术(SEM)对包覆效果进行了分析和研究,对积分进料工艺进行了结晶学方面的分析,提出了积分进料工艺的数学模型。结果表明,包覆层分布均匀、稳定;使用改性后材料制备的镍电极,其电阻降低,活性材料的利用率提高,大电流充放电性能得到了明显的改进。  相似文献   

16.
采用水热法合成Ni(OH)_2-VS_2纳米复合材料,通过X射线衍射(XRD)、扫描电子显微镜(SEM)等对复合材料物相及形貌进行表征.将所得的复合材料用作超级电容器电极材料,通过循环伏安法、恒电流充放电法以及交流阻抗法对Ni(OH)_2-VS_2纳米复合材料的电化学性能进行评价.同时探讨了Ni(OH)2与VS2的不同质量比对复合材料电化学性能的影响.结果表明:Ni(OH)2与VS2的质量比为5∶1时所制备的Ni(OH)_2-VS_2纳米复合材料具有更优异的电化学性能.在电流密度为1A/g时,比电容最高可达到4021F/g,且在电流密度为5A/g下进行500次充放电测试,电容保持率仍在80%以上.  相似文献   

17.
采用粉末微电极技术,通过循环伏安法对Ni(OH)2使用寿命的测定进行了研究.通过控制微电极孔穴深度,使电极过程不受液相扩散控制,从而提高了电极的充放电电流.在电极循环过程中,放电峰电流随着循环次数而变化,从而反映出电极的循环性能.在每次循环扫描过程中,充电深度达到75%,能够满足常规检测的要求.对含Co与不含Co两种Ni(OH)2的检测结果说明,Co有利于延长Ni(OH)2的寿命,这一点与已往的结论是相符的.应用这一技术,完成一次测试所需时间不到10h.这种方法对于研究Ni(OH)2掺杂元素对寿命的影响是非常快速而有效的.  相似文献   

18.
首先通过多周期的电化学循环伏安处理法在Ni金属丝(Niw)上原位生长Ni(OH)2/NiOOH活性层作为电化学氧化葡萄糖的电极材料,然后通过逐个周期改变葡萄糖浓度(1~15 mmol/L)的循环伏安法,研究了葡萄糖在电极上的氧化机理及动力学特征,详细分析了不同电位下氧化电流与葡萄糖浓度的数学关系。结果表明:葡萄糖的电化学氧化机理是基于NiOOH对葡萄糖的化学氧化和电化学氧化再生NiOOH的耦合过程;0.16~0.24 V为葡萄糖氧化电化学控制区;在0.24~0.36 V间,响应电流随葡萄糖浓度呈等阶梯式增加,为典型的扩散控制。进一步研究表明所制备的Ni(OH)2/NiOOH/Niw电极在葡萄糖定量分析时展现了较好的线性关系(10 μmol/L~5.5 mmol/L,R2=0.9999),灵敏度达到62.7 μA/(mmol·L-1),且对模拟腹膜透析液、血液中常见共存物展现了良好的抗干扰能力。  相似文献   

19.
采用电化学方法制备了纳米氢氧化镍/过氧化聚吡咯复合膜修饰电极(Nano-Ni(OH)2/PPyox),研究了该修饰电极的电化学性质及其电催化活性.结果表明:在0.10 mol·L-1 NaOH溶液中,该修饰电极对葡萄糖具有较强的电催化活性,且具有良好的抗干扰性.在优化实验条件下,安培法检测葡萄糖的线性范围为2.0×10-7 ~5.0×10-5 mol·L-1(r =0.999 7)和5.0×10-5~1.0×10-3 mol·L-1(r=0.999 4),灵敏度分别为1017 μA·mM-1 ·cm-2和733 μA·mM-1·cm-2.  相似文献   

20.
以氯化镁和氨水为原料,在室温下制得Mg(OH)2,在不同的反应介质中对Mg(OH)2进行水热处理,制备出了超细、高纯的Mg(OH)2颗粒,利用X射线衍射仪(XRD)和扫描电子显微镜(SEM)对所制得Mg(OH)2颗粒的晶相、形貌和颗粒尺寸进行了表征.研究结果表明,水热条件下反应介质对Mg(OH)2晶体的形成有十分显著的影响,NaOH溶液、乙二胺和乙醇溶液能够显著改善Mg(OH)2晶体的晶形和分散性.初步探讨了水热条件下反应介质对Mg(OH)2晶形的影响机制.  相似文献   

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