Titanium dioxides (TiO2) nanoarchitectures including microspheres surrounded by nanosheets were synthesized using simple, quick and effective hydrothermal method with moderate temperature (150 °C). We systematically investigated how reaction time affected final morphologies
of TiO2. At reaction times equal to 4 and 8 hours (named as TS-4 and TS-8, respectively), TiO2 formed with morphology of irregular microspheres. At longer reaction times (12 hours, named as TS-12), urchin-like TiO2 nanocrystals formed. Photocatalytic activities
of the formed TiO2 with different morphologies were evaluated against decomposition of methylene orange and blue (MO and MB, respectively) as well as rose-bengal (RB). Urchin-like TiO2 demonstrated high degradation ratio similar to the commercial catalyst PS 25 on MO
(96%). Degradation ratios of samples synthetized for 4 and 8 hours were much lower: 60 and 80%, respectively. During 30 minutes reaction time, TiO2 with urchin-like morphology showed much higher selectivity towards neutralization of MB (99.5%) than towards MO (73%) and RB (88.7%).