Dissertation > Excellent graduate degree dissertation topics show

Study on the gel and capacitive properties of manganese oxide gas prepared by sol gel method

Author: ZhangMiao
Tutor: LiuZongHuai
School: Shaanxi Normal University
Course: Materials Science
Keywords: aerogel manganese oxide nickel manganese oxide large surface area capacitance
CLC: O614.711
Type: Master's thesis
Year: 2012
Downloads: 95
Quote: 0
Read: Download Dissertation

Abstract


Because manganese oxide materials have low cost, low toxicity, environmental safety, as well as variable structure, they have been widely used in ion-exchange, molecular absorption, catalysis, and electrochemical supercapacitor. Although there are many advantages, manganese oxide materials also show some drawbacks such as poor electronic and ionic conductivity, low surface area and dissolution problem in their application. In order to overcome these drawbacks, many studies on the fabrication and functionalization of maganese oxides with different structures and morphlogies have been carried out. In this thesis, Mn3O4and NiMn2O4nanomaterials with large surface area and mesopore characteristic are prepared though sol-gel process and followed by calcining treatment. Meanwhile, the obtained Mn3O4and NiMn2O4nanomaterials are characterized and their capacitance is investigated.This thesis mainly consists of three sections, reviewer, experiments and conclusion. Introduction part (chapter1) reviews the structure, classfications, the formation and drying of the gel, the preparation method and application of manganese oxides Experiment section (chapter2,3) consists of the fabrication, characterization and property of Mn3O4and NiMn2O4nanomaterials with large surface area and mesopore characteristic. Mn(NO3)2-6H2O is used as precursor and epoxide is used as gelation agent, the maganese oxide aerogel has been firstly prepared though sol-gel technology and then combined with supercritical drying. MnO4nanomaterial with large surface area and mesopore characteristic is prepared by calcining the maganese oxide aerogel at different temperature and its capacitance is investigated in chpter2. The nickel maganese oxide aerogel has been prepared via the same method, and NiMn2O4nanomaterial with large surface area and mesopore characteristic is prepared by calcining the nickel maganese oxide aerogel at different temperature and its capacitance is investigated in chpter3. And the conclusion and the advices for the study is conclused in chapter4.(1) Mn(NO3)2-6H2O is used as precursor and epoxide is used as gelation agent, the maganese oxide aerogel has been firstly prepared though sol-gel technology and then combined with supercritical drying. Mn3O4nanomaterial with large surface area and mesopore characteristic is prepared by calcining the maganese oxide aerogel at300℃ for5hours. The N2adsorption/desorption results show that Mn3O4nanomaterial has a specific surface area of106m2/g with a mesoporous structure. The electrochemical property is characterized by cyclic voltammetry in1mol/L Na2SO4electrolyte. The Mn3O4nanomaterial shows an ideal capacitive behavior, and its initial capacitance value is209F/g at a scan rate of5mV/s. The capacitance of Mn3O4nanomaterial connects with the scan rate, and the values are respectively209F/g,194F/g,144F/g, and109F/g at a corresponding scan rate of5mV/s,10mV/s,20mV/s, and50mV/s.(2) Mn(NO3)2·6H2O and Ni(NO3)2·6H2O are used as precursor and epoxide is used as gelation agent, the nickel maganese oxide aerogel has been firstly prepared though sol-gel technology and then combined with supercritical drying. NiMn2O4nanomaterial with large surface area and mesopore characteristic is prepared by calcining the nickel maganese oxide aerogel at300℃for5hours. The N2adsorption/desorption results show that NiMn2O4nanomaterial has a specific surface area of201m2/g with a mesoporous structure and a suitable pore size around8-10nm. The electrochemical property is characterized by cyclic voltammetry both in1mol/L Na2SO4electrolyte and9mol/L KOH electrolyte. The prepared NiMn2O4material not only exhibits an ideal capacitive behavior, but also shows good cycling stability in a neutral electrolyte, and its initial capacitance value is243F/g at a scan rate of5mV/s. The initial capacitance value of98%can be maintained after5000cycles of the operation. In addition, although NiMn2O4material shows a large capacitance in9mol/L KOH electrolyte in compare with that in1mol/L Na2SO4electrolyte at the same scan rates, a relative poor cycling stability is observed due to the dissolution of NiMn2O4material in KOH electrolyte(3) Sol-gel process combined with supercritical CO2drying is one of the effective methods to prepare the maganese oxide areogels with large surface aera, mesoporous structure and different morphology.

Related Dissertations

  1. High Speed Frequency Measurment and Non-Linearity Correction of Frequency Modulated Capacitive Displacement Sensor,TH822
  2. 12-Tungstophosphoric Acid Modified-Zirconia Aerogel as a Solid Acid for THF Polymerization,TQ316.314
  3. Prepration of Manganses Dioxide and Investigation on the Performance of Supercapacitor,TM53
  4. Study on Electhode Materials of High Surface Area Activated Carbon with Different Pore Structures for Supercapacitor,TM53
  5. Compact microwave low pass filter,TN713.4
  6. Characteristic Impedance of Microbial Fuel Cells (MFCs) and Nitrafication in a Biocathode of the MFCs,TM911.4
  7. Design of Digital Walkie-talkie Base Band Module Circuit and It’s EMC,TN929.54
  8. Preparation and Properties of 2 composite airgel catalyst Ni (Co) / SiO ,O643.36
  9. Structure and Catalytic Performance of Silver-Manganese Oxide Sieves,O643.3
  10. Preparation of Nickel Hydroxide and Nickel Hydroxyl Oxide and Their Electrochemical Performances,O614.813
  11. Supercapacitor ruthenium oxide -based composite film electrode preparation and properties of,TM53
  12. Design and Synthesis of Graphene-Based Composites for Supercapacitor Application,TM53
  13. Preparation and Properties of Hydroxides, Oxides/Graphene Composites as Electrode Materials for Supercapacitor,TM53
  14. Preparation and Capacitance Performance of Mn/V Composite Oxide,O646
  15. Preparation and storage of the electrode material for electrochemical capacitors electrical properties,TM53
  16. Preparation and Properties of Graphene Oxide and Graphene Oxide-based Composites,TB383.1
  17. Preparation and Application of Aerogel Microspheres,TQ427
  18. Preparation、 Optimization and Mechanism of Polymer Photovoltaic Devices and Carbon Aerogel Counter Electrode,TM914.4
  19. Controllable Sythesis and Catalytic Property of a-MnO2 Nanoparticles,O643.36
  20. Study on Synthesis and Electrochemistry Application of TiO2-carbon Aerogels,TM53
  21. Sol - Preparation and properties of hydrophobic airgel SiO_2 gel method.,TB383.1

CLC: > Mathematical sciences and chemical > Chemistry > Inorganic Chemistry > Metal elements and their compounds > The Ⅶ group metal elements and their compounds > The manganese Vice Family ( VII B group metal elements) > Manganese Mn
© 2012 www.DissertationTopic.Net  Mobile