Facile preparation of Ti3+ self-doped TiO2 microspheres with lichi-like surface through selective etching

Abstract

A novel composite Al(acac)3/Al-TiO2 is synthesized via facile flame thermal method and Ti3+self-doped TiO2 microspheres with lichi-like surface is prepared by selective etching the composite with HCl. The samples are investigated by scanning electron microscopy (SEM), inductively coupled plasma-atomic emission spectrometry (ICP), X-ray diffraction (XRD), electron paramagnetic resonance (EPR) and X-ray photoelectron spectra (XPS), respectively. SEM shows that microspherical TiO2 with lichi-like surface is obtained and the rough surface is resulted by etching Al(acac)3 in the composite, which is further confirmed by ICP and iodoform reaction from the characterizations to the etching solution. EPR and XPS indicate the presence of Ti3+on the surface of the microspheres after HCl etching. The XPS results also imply that Ti3+may be formed by removing the partly doped Al in the resulted samples. No reducer or reducing condition are needed through the whole synthesis procedures and it would be a new strategy for the preparation of nanostructured TiO2.