The photocatalytic activity of the TiO2 samples was tested
for the photodegradation of gaseous benzene in air. Figure 6
shows the conversion of benzene under UV irradiation. The
HNT sample shows the highest performance in this photocatalytic
process. The photocatalytic conversion ratio of benzene
over HNT is 95.9% after 150 min, and Fig. 7 shows that the
amount of CO2 produced over HNT is up to 375.84 mg/m3,
which is much higher than that produced over P25 (192.01
mg/m3). In contrast to the HNT catalyst, the conversions of
benzene over NNT, ANT, PT, and commercial P25 are 91%,
72.7%, 84.6%, and 67%, respectively. The data in Fig. 8 show
that the photocatalytic conversion of benzene generally follows
first‐order kinetics, and the rate constant for HNT (k =
18.7×10–3 min–1) is higher than those for PT (k = 11.9×10–3