
529Chemical Nanosensors
conduction band edge at the surface, while the thickness is set to the gap (L)
between adjacent crystals.
How does gas adsorption on small crystals differ from that on larger ones?
What is meant by regional and volume depletion? Consider the situation after
the depletion depth has reached the radius of spheres or necks. Such a
situation ensues easily when the spheres are more compact in size or gas
adsorption is strengthened. The gas adsorption equilibrium on small crys-
tals is much different from that on large crystals. There are two different
cases: (i) In the case of large crystals, depletion ...