Gas diffusion and sorption in nanoceramic semiconductors are studied using atomistic simulation techniques and numerical results are presented for a variety of sorbate–sorbent systems. SnO2,BaTiO3, CuO, and MgO substrates are built on the computer using lattice constants and atomic parameters that have been either measured or computed by ab initio methods. The Universal force field is employed here for the description of both intramolecular and nonbonded interactions for various gas sorbates, including CH4, CO, CO2, and O2, pure and in binary mixtures. Mean residence times are determined by molecular dynamics computations, whereas the Henry constant and the isosteric heat of adsorption are estimated by a Monte Carlo technique. The effects of surface hydroxylation on the diffusion and sorption characteristics are quantified and discussed in view of their significance in practical gas sensing applications. The importance of fast diffusion on the response time of the sensitive layer and of the sorption efficiency on the overall sensitivity as well as the potential synergy of the two phenomena are discussed.

1.
M. J.
Willett
,
V. N.
Burganos
,
C. D.
Tsakiroglou
, and
A. C.
Payatakes
,
Sens. Actuators B
53
,
76
(
1998
).
2.
V. N.
Burganos
,
J. Chem. Phys.
98
,
2268
(
1993
);
V. N.
Burganos
,
J. Chem. Phys.
109
,
6772
(
1998
), and references therein.
3.
W.
Göpel
,
Sens. Actuators B
18-19
,
1
(
1994
).
4.
V. A.
Gercher
and
D. F.
Cox
,
Surf. Sci.
322
,
177
(
1995
).
5.
M. A.
Henderson
,
Surf. Sci.
319
,
315
(
1994
).
6.
M. A.
Henderson
,
Surf. Sci.
355
,
151
(
1996
).
7.
J. Tribout, F. Chancel, M.-I. Baraton, H. Ferkel, and W. Riehemann, Key Engineering Materials Proceedings of the 1997 5th Conference and Exhibition of the European Ceramic Society, 1997, Vol. 2, p. 1341 (unpublished).
8.
H.
Onishi
,
T.
Aruga
,
C.
Egawa
, and
Y.
Iwasawa
,
J. Chem. Soc., Faraday Trans. 1
85
,
2597
(
1989
).
9.
J. F.
McAleer
,
A.
Maignan
,
P. T.
Moseley
, and
D. E.
Williams
,
J. Chem. Soc., Faraday Trans. 1
85
,
783
(
1989
).
10.
T.
Bredow
and
K.
Jug
,
Surf. Sci.
327
,
398
(
1995
).
11.
S. P.
Bates
,
G.
Kresse
, and
M. J.
Gillan
,
Surf. Sci.
385
,
386
(
1997
).
12.
A.
Fahmi
and
C.
Minot
,
Surf. Sci.
304
,
343
(
1994
).
13.
I.
Manassidis
,
J.
Goniakowski
,
L. N.
Kantorovich
, and
M. J.
Gillan
,
Surf. Sci.
339
,
258
(
1995
).
14.
J.
Goniakowski
,
J. M.
Holender
,
L. N.
Kantorovich
,
M. J.
Gillan
, and
J. A.
White
,
Phys. Rev. B
53
,
957
(
1996
).
15.
J.
Goniakowski
and
M. J.
Gillan
,
Surf. Sci.
350
,
145
(
1996
).
16.
J.
Goniakowski
,
S.
Rousso
, and
C.
Noguera
,
Surf. Sci.
284
,
315
(
1993
).
17.
J.
Goniakowski
and
C.
Noguera
,
Surf. Sci.
319
,
68
(
1994
).
18.
J.
Padilla
and
D.
Vanderbilt
,
Phys. Rev. B
56
,
1625
(
1997
).
19.
H.-Y.
Lee
,
W.
Riehemann
, and
B. L.
Mordike
,
J. Eur. Ceram. Soc.
10
,
245
(
1992
).
20.
H.-Y.
Lee
,
W.
Riehemann
, and
B. L.
Mordike
,
Mater. Sci. Forum
94-96
,
849
(
1992
).
21.
H. Ferkel, J. Naser, W. Riehemann, and B. L. Mordike, Fine Solid Particles, edited by J. Schwedes and S. Bernodat (Shaker, Aachen, 1997), p. 144.
22.
E.
Müller
,
C.
Oestreich
,
U.
Popp
,
G.
Michael
,
G.
Staupendahl
, and
K.-H.
Henneberg
,
KONA
13
,
79
(
1995
).
23.
D. M.
Razmus
and
C. K.
Hall
,
AIChE. J.
37
,
5
(
1991
).
24.
J. M. D.
MacElroy
and
K.
Raghavan
,
J. Chem. Phys.
93
,
2068
(
1990
).
25.
R. J.-M.
Pellenq
and
D.
Nicholson
,
Langmuir
11
,
1626
(
1995
).
26.
X.
Yi
,
K. S.
Shing
, and
M.
Sahimi
,
AIChE. J.
41
,
456
(
1995
).
27.
M. P. Allen and D. J. Tildesley, Computer Simulation of Liquids (Oxford, New York, 1987).
28.
A. K.
Rappé
,
C. J.
Casewit
,
K. S.
Colwell
,
W. A.
Goddard
III
, and
W. M.
Skiff
,
J. Am. Chem. Soc.
114
,
10024
(
1992
).
29.
C. J.
Casewit
,
K. S.
Colwell
, and
A. K.
Rappé
,
J. Am. Chem. Soc.
114
,
10035
(
1992
).
30.
C. J.
Casewit
,
K. S.
Colwell
, and
A. K.
Rappé
,
J. Am. Chem. Soc.
114
,
10046
(
1992
).
31.
A. K.
Rappé
,
K. S.
Colwell
, and
C. J.
Casewit
,
Inorg. Chem.
32
,
3438
(
1993
).
32.
A. K.
Rappé
and
W. A.
Goddard
III
,
J. Phys. Chem.
95
,
3358
(
1991
).
33.
N.
Agmon
,
J. Chem. Phys.
81
,
3644
(
1984
).
34.
A.
Lakhlifi
and
C.
Girardet
,
Surf. Sci.
241
,
400
(
1991
).
35.
L. N.
Kantorovich
and
M. J.
Gillan
,
Surf. Sci.
374
,
373
(
1997
).
36.
K. Madih, thesis, University of Aix, Marseille, France, 1986;
M.
Trabelsi
,
K.
Madih
, and
J. P.
Coulomb
,
Phase Transit.
30
,
103
(
1991
);
K.
Madih
,
B.
Croset
,
J. P.
Coulomb
, and
H. J.
Lauter
,
Europhys. Lett.
8
,
459
(
1989
).
This content is only available via PDF.
You do not currently have access to this content.