3.1.2. Scanning electron microscopy
Morphologies of N-doped TiO
revealed by SEMmicrographs are
shown in Fig. 3. All samples appeared as agglomerations of smaller
particles. Cluster sizes of the as-synthesised catalyst were strongly
dependent on the type of nitrogen dopant. The TiO
2
powder in all
cases presented aggregates consisting of smaller particles (100 nm
for TiO
2
/TEN) to larger particles (about 500 nm for TiO
2
/DEA) with
a high tendency for crystallisation. Fine particles with a very homogeneous
size distribution can be seen in TiO
/urea.
TEM images (Fig. 4) of N-doped TiO
2
2
show significant differences
amongst the studied samples. The anatase phase in TiO
/DEA
was in a uniform dimension with an average crystal size of about
2
2