Nanofiber immobilized CeO2/dendrimer nanoparticles : an efficient photocatalyst in the visible and the UV

The contribution of a nanofiber based support and dendrimer coating on the visible light photocatalytic activity of CeO2 (ceria) nanoparticles towards phenol and azorubine dye was investigated. CeO2 nanoparticles were immobilized on electrospun nanofiber mats obtained from pullulan/poly(vinyl alcohol)/poly(acrylic acid) (Pul/PVA/PAA) blends and the CeO2 surface was modified with generation 3.0 PAMAM dendrimer. The catalytic activity was studied between pH 4 and 11 and it was compared with free CeO2- and free TiO2-nanoparticles for reference. The supported catalyst was photocatalytically active towards both phenol and azorubine and immobilization increased its reactivity by a factor of three. The mat type nature of the immobilized catalyst was also beneficial for simple recycling. XPS spectra revealed the presence of a Ce3+ state and the formation of hydroxyl radicals was shown using fluorescence spectroscopy.