Synthesis and characterization of anodic titania nanotubes for supercapacitor application / Zulkarnain Endut
Over the past decade, titania nanotube materials have attracted increasing scientific and technological attention ranging from usage in the fields of biomedical applications to energy conversion. Titania nanotubes can be synthesized using a simple and low-cost self-organizing anodization method b...
Saved in:
Main Author: | |
---|---|
Format: | Thesis |
Published: |
2013
|
Subjects: | |
Online Access: | http://studentsrepo.um.edu.my/8292/4/OFFICIAL_PhD_Thesis_%2D_Zulkarnain_Bin_Endut_KHA090070.pdf http://studentsrepo.um.edu.my/8292/ |
Tags: |
Add Tag
No Tags, Be the first to tag this record!
|
Summary: | Over the past decade, titania nanotube materials have attracted increasing
scientific and technological attention ranging from usage in the fields of biomedical
applications to energy conversion. Titania nanotubes can be synthesized using a simple
and low-cost self-organizing anodization method but is capable of producing highly
ordered titania nanotube structures.This nanostructure grown directly on the conductive
substrate can offer unique physical properties such as high specific surface area, lower
electron recombination and excellent charge-transfer properties. Based on this
motivation, this thesis attempts to synthesis, to apply, to investigate and to enhance this
titania nanotubes as a binder-free supercapacitor electrode in which titanium foil can be
used as a current collector while their nanotubular structure is used as charge storing
and releasing area. The aim of this work is to study the structure, morphology, chemical
composition and electrochemical capacitance performance by means of various
characterization tools such as field emission scanning electron microscopy (FESEM), xray
diffraction (XRD), x-ray photoelectron spectroscopy (XPS), cyclic voltammetry
(CV), galvanostatic charge-discharge testing (CD), electrochemical impedance
spectroscopy (EIS) and Mott-Schottky analysis. The thesis describes the mechanism of
titania nanotube formation and growth during anodization of titanium in NH4F/ethylene
glycol electrolyte at 45 V applied voltage that was investigated using FESEM. The
initial stage of the anodization occurs with the formation of a compact oxide layer with
nanoscale pits. With the increase of anodization time, the pits transform to larger and
deeper pores due to the integration of the smaller and larger pores, finally creating selfordered
titania nanotubes. The porous structure increases electrochemical capacitance
from 18.3 μF cm-2 for 10-s anodization time to 49.9 μF cm-2 for 1800-s anodization
time. The CV transforms from a near symmetry rectangular shape to x-axis symmetry |
---|