Pressure Dependent Synthesis and Enhanced Photocatalytic Activity of TiO2 Nano-Structures

摘要

In this work, three dimensional TiO2 nanostructures have been successfully synthesized by using microwave assisted hydrothermal technique. The samples were characterized in detail by XRD, SEM, and UV-visible spectrometry techniques. Besides, photocatalytic characteristics were evaluated through measuring the degradation rate of methylene blue in aqueous solution. We were able to control the morphology and growth mode of TiO2 nanostructures by changing the hydrothermal pressure during synthesis. The samples possessed a rutile matrix and the crystallinity of the samples was significantly enhanced when the hydrothermal pressure was increased from 125 to 200 psi. FE-SEM image shows that the TiO2 nanostructures consist of several nanorods coming out of a single core and have very sharp edges. Also, it was observed that changing the hydrothermal pressure results change in the aspect ratio of TiO2 nanostructures. The sample with high aspect ratio (AR similar to 13) shows enhanced photocatalytic activity. We established a correlation between the aspect ratio and the photocatalytic characteristics of the TiO2 nanostructures.