Photonic crystals in biology

Poster Session, Tuesday, June 15
Theme A1 - B702
The Hydrogen Sensing Properties of Pd Nanowires
ennik 1 *, Necmettin K 1 and Zafer Ziya Öztürk 1, 2
1 Gebze Institute of Technology, Science Faculty, Department of Physics, Kocaeli 41400, Turkey
2 TUBITAK Marmara Research Centre, P.O. Box 21, 41470 Gebze Kocaeli, Turkey
Abstract- In this study, Pd nanowires are successfully fabricated directly on Highly Oriented Pyrolytic Graphite (HOPG) depending on time
using palladium nitrate solution at room temperature and then the hydrogen sensing properties of the fabricated these structures are investigated
in the various concentrations of H 2 . Nanowires with diameters approximately 100 nm are obtained by electrodeposition onto the step edges on
the surface of a ZYH quality of HOPG. The sensitivity is observed approximately 2 % for 1000 ppm H2 at room temperature.
Hydrogen has numerous applications in industry, such as
chemical production, fuel cell technology, and rocket engines
[1]. However, the flammable and explosive properties of
hydrogen gas make its detection an important issue [2]. That’s
why nanotechnology has been used and become more vogues
day by day. Nanostructures such as nanotubes [3] and
nanowires [4] have been fabricated for H 2 gas sensing.
Pd plating solutions were used: aqueous 2 mM Pd(NO3) 2 ,
0.1 M HClO 4 . These solutions were prepared using nanopure
water (r ~
experiment. The surface of highly oriented pyrolytic graphite
(HOPG) crystal was cleaved using adhesive tape immediately
prior to use. The growth of metal nanowires was carried out
using the 3 - pulse potential program.
The values for the oxidation potential, E
ox
, the nucleation
potential, E nuc
, and the growth potential, E grow
are 0.8 V, -
0.8 V and 0.3 V, respectively. The oxidation potential was 5 s
for activating the electrodeposition. The nucleation potential
was chosen for 0.01 s and this potential determined the
forming of nanowires through growth potential and growth
time that are called deposition potential and deposition time,
respectively. Following deposition, the graphite was removed
from the plating solution, rinsed with water, and air dried prior
to characterization using SEM.
sensor were purged with 200 sccm high purity N 2 . As shown
in Figure 2, the resistance of the sensor was increased by the
increasing concentrations of H 2 .
Figure 2. The resistance versus the concentrations of hydrogen for the
Pd nanowire sensor [4]
In conclusion, electrochemical step edge decoration (ESED)
is very general method for preparing nanowires that are size
and shape uniformity. Pd nanowires fabricated on HOPG were
used as H 2 gas sensor. The results of gas sensing
measurements have shown that Pd nanowires sensor is
abundant at room temperature.
This work was supported by TUBITAK under Grant No.
TBAG106T546.
*Corresponding author: zozturk@gyte.edu.tr
Figure 1. Pd Nanowires Electrodeposition for 600 s (scale: 2 [4]
Pd nanowires were fabricated on HOPG for 600 s. These
nanowires were approximately 100 nm in diameter, as seen in
figure 1 [4]. After the fabrication of Pd nanowires, they were
transferred fro m the HOPG surface to a glass slide droped
with cyanoacrylate. The cyanoacrylate film was hardened for
8 hours, and then an array of gold (Au) electrode was coated
by the evaporation using a mask. The device was prepared for
H 2The gas sensing.
device was exposed to various concentrations of H 2 in a
home made measurement cell. After reaching saturation the
[1] Bevenot X, Trouillet A, Veillas C, Gagnaire H, Clement M.
Hydrogen leak detection using an optical fibre sensor for aerospace
applications. Sensors and Actuators B: Chemical 2000;67:57–67.
[2] Yazdi N, Ayazi F, Najafi K. Micromachined inertial sensors.
Proceedings of the IEEE 1998;86:1640–59.
[3] Erdem Sennik, Zeliha Colak,
Ozturk, Synthesis of highly-ordered TiO 2 nanotubes for a hydrogen
sensor, International Journal of Hydrogen Energy
(doi:10.1016/j.ijhydene.2010.01.100) 2010.
dependent H2 gas sensing properties of fabricated Pd nanowires
using HOPG submitted to International Journal of Hydrogen Energy
6th Nanoscience and Nanotechnology Conference, zmir, 2010 392