3.1. Morphology and Crystal Structure. Figure 1a,b depicts
typical TEM images of the products prepared in water without
SDS surfactant at lower and higher magnifications. Nanorods
with the morphology of single straight needle were observed
on the amorphous carbon film. The average width of nanorods
is 32.2 nm. The nanorods have sharp edges as shown in Figure
1b. Figure 1c reveals the corresponding SAED pattern of the
nanorods shown in Figure 1b. A transmission electron diffraction
pattern from a single crystal can be obviously recognized. The
diffraction pattern can be indexed as the [011h0] zone axis pattern
of a hexagonal closed-pack structure. The lattice constants of
the nanorods estimated from the pattern was confirmed to
coincide with those of wurtzite ZnO (P63mc, JCPDS No. 36-
1451, a ) 0.325 nm, c ) 0.521 nm). Some diffuse streaks
around the diffraction spots were observed along reciprocal
[2h110] and [21h1h0] directions. The directions of major axes in
all nanorods are parallel to the [0001] direction of each ZnO
crystal.