Enhanced capacitance of composite TiO2 nanotube / boron-doped diamond electrodes studied by impedance spectroscopy
PBN-AR
Instytucja
Wydział Elektroniki, Telekomunikacji i Informatyki (Politechnika Gdańska)
Informacje podstawowe
Główny język publikacji
ENG
Czasopismo
NANOSCALE
ISSN
2040-3364
EISSN
Wydawca
DOI
URL
Rok publikacji
2015
Numer zeszytu
Strony od-do
551-558
Numer tomu
7
Identyfikator DOI
Liczba arkuszy
Słowa kluczowe
BORON-DOPED DIAMOND
IMPEDANCE SPECTROSCOPY
TIO2
Streszczenia
Język
Treść
We report on the novel composite nanostructures based on boron-doped diamond thin film grown on top of TiO2 nanotubes. The nanostructures made of BDD-modified titania nanotubes showed an increase in activity and performance when used as electrodes in electrochemical environments. The BDD thin films (~200-500 nm) were deposited using microwave plasma assisted chemical vapor deposition (MW PA CVD) onto anodically fabricated TiO2 nanotube arrays. The influence of boron-doping level, methane admixture and growth time on the performance of Ti/TiO2/BDD electrode was studied in detail. Scanning electron microscopy (SEM) was applied to investigate the surface morphology and grain size distribution. Moreover, the chemical composition of TiO2/BDD electrodes was investigated by means of micro-Raman Spectroscopy. The composite electrodes TiO2/BDD are characterized by the significantly higher capacitive current comparing to BDD film deposited directly onto Ti substrate. The novel composite electrode of TiO2 nanotube array overgrown by boron-doped diamond (BDD) immersed in 0.1 M NaNO3 can deliver specific capacitance of 2.10, 4.79, 7.46 mF cm-2 at a scan rate of 10 mV/s for [B]/[C] ratio 2k, 5k and 10k, respectively. The substantial improvement of electrochemical performance and excellent rate capability could be attributed to synergistic effect of TiO2 treatment in CH4:H2 plasma and high electrical conductivity of BDD layer. Analysis of electrochemical impedance spectra according to electric equivalent circuit allows to determine surface area on the basis of value of constant phase element.
Inne
System-identifier
129684