Typical Synthesis and Environmental Application of Novel Ti Nanoparticles - Advanced Materials for Agriculture, Food and Environmental Safety - page 441

1.0

0.8

0.6

NMT1
NMT2
P25 T1
NMT3
CMT
ZMT
NM
NT
1

0.4

0.2

0.0 0

2 3 4 5 6

Irradiation Time (h)

Figure 15.13 Photocatalytic activity on methyl orange and band gap energy of NMT1
and other prepared ctalysts in presence of UV light.

found that Bi 12 TiO 20 and perovskites Bi 4 Ti 3 O 12 shows high photocatalytic
activity against methyl orange [149-150]. It has been demonstrated that
the dopant ions or oxides can increase the quantum ei ciency of the het-
erogeneous photocatalytic property by acting as electron/hole traps or by
altering the e - /h + pair recombination rate, and are therefore an ef ective way
to enhance the photocatalytic activity. Yao et al. have observed that 0.5 at%
Ba doping in Bi 12 TiO 20 , La (Fe)-doped bismuth titanate, shows maximum
photocatalytic activity compared to Bi 12 TiO 20 [151]. Figure 15.14A shows
TEM images of NM x BT 1−x ( x = 0.01) composite [89], which has maximum
photocatalytic activity under the experimental condition. h e average par-
ticle size of NM x BT 1−x ( x = 0.01) was found to be around 30±2 nm calcu-
lated from images of TEM using ImageJ sot ware; the SAD (selected area
dif raction) pattern as well as the high-resolution TEM of a highlighted
particle from Figure 15.14B are presented in Figure 15.14C and 15.14D.
h e SAD pattern of NM x BT 1−x ( x = 0.01) clearly indicates that the crys-
tal structure is close to parent compound Bi 2 Ti 4 O 11 . h e high-resolution
transmission electron microscopy (HRTEM) for the sample NM x BT 1−x ( x
= 0.01) shown in Figure 15.14D, clearly demonstrates the lattice fringes for
the monoclinic phase of Bi 2 Ti 4 O 11 . From the micrograph the lattice spacing
in the particle is determined to be 2.969Å, which corresponds to the (113)
plane of the monoclinic phase of these materials.
h e UV-vis dif use rel ectance spectrum of various compositions of
NM x BT 1−x (x = 0.01, 0.05, 0.1) composite and of Bi 2 Ti 4 O 11 and NiMoO 4
are also presented in Figure 15.15. h e band gap absorption edges of