Effect of Morphology of Titanium Dioxide Nanoparticles on Photocatalytic Activity

Abstract

Dispersing nanoparticles into the matrix is a simple but effective method to improve properties of coating layer. Titanium dioxide (TiO2), known for its photocatalytic activity (PCA) to degrade organic substances and to protect microbial infection, is considered to be potential candidate. However, intense light is required to achieve high PCA. Scattering layer composing of hollow TiO2 nanoparticles, known as light harvester in solar cell devices, may be suitable for photocatalysis at lower light intensity. In this work, we studied the effect of hollow morphology to the PCA of TiO2 nanoparticles. Hollow TiO2 nanoparticles were successfully synthesized using hard-template-assisted sol-gel method. Transmission Electron Microscope (TEM) images show hollow TiO2 nanoparticles possessing 125-nm hollow core and 50-nm TiO2 shell. X-ray Diffraction (XRD) results revealed no crystalline peak for both calcined and non-calcined samples, but difference for each sample was reported by Ultraviolet-Visible Diffuse Reflectance Spectroscopy (UV-DRS). UV-DRS spectrum showed the higher diffuse reflectance for both hollow TiO2 samples than the dense counterpart, suggesting multiple light scattering and high reflection. However, energy bandgaps of amorphous and calcined hollow TiO2 samples are higher than dense counterparts.