类普鲁士蓝为前驱体制备纳米NiO及其电化学电容行为

Nanosized nickel oxide was synthesized by immersing the precursor NiHCNFe into 1 mol·L^-1 KOH solution to obtain nickel hydroxide (Ni(OH)₂) and then annealing in air at 300 ℃. X-ray diffraction (XRD) and transmission electron microscopy (TEM) tests showed the prepared samples were rhombohedral crystalline structure of NiO with uniform grain and with a diameter of about 8 nm. Electrochemical properties of NiO were examined by cyclic voltammetry, ac impedance and galvanostatic charge-discharge tests. The results demonstrated that nickel oxide had a good capacitive behavior and cyclability due to its nanostructure. The highest specific capacitance of nickel oxide was about 303 F·g^-1 at a charge/discharge current density of 5 mA·cm^-2 in 6 mol·L^-1 KOH solution.     

纳米晶构筑一维多孔氧化锌的合成与表征

One-dimensional porous zinc oxide was prepared via the calcination of zinc oxalate precursor obtained by solvothermal method. The products were characterized by XRD, SEM, TEM, photoluminescence (PL) spectrum and nitrogen adsorption-desorption. The results show that the obtained zinc oxide sample is porous and constructed by nanoparticles about 30 nm in size. The specific surface area and total pore volume are 126 m²·g^-1 and 0.13 cm³·g^-1, respectively． The PL properties related with defects in ZnO nanoparticles were discussed for porous zinc oxide samples.     

明胶基多孔碳球电极材料的制备及电化学性能研究

Gelatin-based porous carbon beads have been fabricated from gelatin micro-spheres by means of solidification, carbonization and chemical activation with KOH. The physical properties of gelatin-based porous carbon beads were studied by a t-plot method based on N₂ adsorption isotherms. The gelatin-based porous carbon beads activated at 800 ℃ exhibited the largest specific surface area and resulted in the highest capacitance. Carbon/carbon super-capacitors cells assembled with the electrode materials in 1.0 mol·L^-1 NEt₄BF₄ / acetonitrile electrolyte have also been studied. The electrochemical properties of gelatin-based porous carbon beads electrode were studied by using constant-current discharge tests. The results indicate that the gelatin-based porous carbon beads electrode is with good cycling stability and specific capacitance of 119.8 F·g^-1.     

纳米氧化锰电极材料的制备和电容特性研究

The nano-MnO₂ as active electrode material for supercapacitor was synthesized by solid-state reaction between KMnO₄ and manganese acetate at room temperature. The products annealed at 100 ℃ and 200 ℃ were characterized by XRD and TEM. The results showed the sample annealed at 100 ℃ was poorly crystallized phase with an average grain size of <20 nm. Electrochemical performances of manganese oxide electrode were investigated by cyclic voltammetry and constant current charge/discharge. The manganese oxide electrode annealed at 100 ℃ in 1 mol·L^-1 Na₂SO₄ aqueous electrolyte exhibited excellent capacitive behavior between -0.2 and +0.8 V (vs SCE). By 5 mA and 10 mA constant current charge/discharge, the nano-MnO₂ annealed at 100 ℃ can provide a specific capacitance of 158.5 F·g^-1 and 151.2 F·g^-1, respectively.     

一种估算多壁碳纳米管电化学容量的方法

Five kinds of multi-walled carbon nanotubes were prepared by CVD(Chemical Vapour Deposition) and purified under the same conditions, then were used as electrodes for super capacitors in order to compare their performance. The differences measured in terms of specific capacitance by galvanostatic cycling were presented, porosity measurements using nitrogen at 77 K made on carbon nanotubes allowd a better understanding of the electrochemical behavior of these carbon nanotubes. The experiment results show that pore diameter in the range of more than 3nm is required to maximize the capacitance in the electrolyte of 1.0 mol·L^-1 LiClO₄/EC+DEC(V_EC∶V_DEC=1∶1), and the BET surface area contributed by this extent is almost linear with the specific capacitance, in which an average value is about 0.11 F·m^-2, and the specific capacitance estimated from above is very close to the value by experiment.     

新生态二氧化锰的性质及pH值影响除砷效果的研究

Fresh MnO₂ was prepared by oxide reduction using KMnO₄ and MnSO₄. The structure and property of the products were characterized by TEM, SEM, XRD and BET, and the effect of pH value was studied on the removal of both As(Ⅴ) and As(Ⅲ). The results show that δ-MnO₂ is spherical, its specific surface is 325 m²·g^-1 with lots of hydroxyl on the surface. Adsorption of fresh MnO₂ of As(Ⅲ) was a corporate action of both oxide reaction and electrostatic adsorption, but the adsorption of As(Ⅴ) was due to electrostatic and anion exchange adsorption.     

电解质材料Sr-和Mg-掺杂LaGaO3的制备及性能研究

A dense La_0.8Sr_0.2Ga_0.83Mg_0.17O_2.815 electrolyte in pure perovskite phase was prepared by a polyacrylic acid assisted solid state reaction method, and the effects of La source on the structure and electrochemical performance were also studied. By means of XRD and SEM, the structure of this material was characterized, and the electrochemical properties were studied through AC impedance diagram. The results show that the sample presents a single perovskite-type phase after sintering at 1 450 ℃ and the relative density is 94%. The specimen has the lower activate energy and higher electrical conductivity at 600 ℃. There are two different activation energy at the turning point of 650 ℃, which are 74.6 and 42.4 kJ·mol^-1, respectively. The electrical conductivity is 0.057 S·cm^-1 and 0.017 S·cm^-1 at the temperature of 800 ℃ and 600 ℃, respectively.     

溶剂热-热解法制备具有纳米孔结构的Co3O4

Nanoporous rhombohedral Co₃O₄ was synthesized by thermal decomposition of the precursor obtained via a solvothermal method in the presence of Co(CH₃COO)₂·4H₂O, urea, sodium dodecyl sulfate (SDS), ethanol and water. The calcined sample was characterized by XRD, FTIR, SEM, TG-DTA, Nitrogen adsorption-desorption, cyclic voltammetry and galvanostatic charge/discharge measurements. The results show that the calcined sample at 400 ℃ is rhombohedral structure Co₃O₄ with nano-porosity assembled by uniform nanosheets. The BET surface area is 49 m²·g^-1 and its specific capacitance as single electrode is up to 233.4 F·g^-1 at 5 mA·cm^-2 current density.     

氢气泡模板电沉积多孔金属镍薄膜

Porous nickel films have been successfully electrodeposited using cathodic hydrogen bubbles as a template. The influence of deposition parameters including concentration, temperature and current density on the films morphologies has been systematically studied. SEM results showed that increase in current density resulted in the deposits with higher pore density and smaller pore size. Both the pore size and thickness of the pore walls increased with the electrolyte temperature range from 20 to 60 ℃ when the other deposition parameters were fixed. Increasing the concentration of NiCl₂ or NH₄Cl in the electrolyte led to the thicker of the pore walls and declined pore size and density. The deposits displayed a dendritic morphology in cross-sectional SEM image. Electrochemical characterization of the porous nickel films after surface oxidation in 1.0 mol·L^-1 NaOH solution showed that specific capacitance as high as 7.2 F·g^-1 could be reached.     

预氧化固气法合成LiNiO2的研究

LiNiO₂ was prepared by reaction of stoichiometric amounts of thoroughly-mixed LiOH·H₂O and preoxidation nanometer-scale Ni₃O₂(OH)₄ powders in O₂ at the temperature of 700℃ for 6h. The products were tested by XRD， XPS， SEM and electrochemistry methods. It was shown that product was LiNiO₂ single-phase， and the valence of nickel was +3; the average size of it was 40nm; its initial charge specific capacity is 168mAh·g^-1 and the coulomb efficiency is 90%; the second charge specific capacity is 160mAh·g^-1 and the coulomb efficiency is 96%.