The structural and photoluminescence studies related to the surface of the TiO2 sol prepared by wet chemical method

The stable anatase TiO2 sol was prepared firstly. The crystallinity and morphology were investigated by XRD, TEM and Raman patterns. The photo-luminescence was used to study the surface electronic structure of TiO2 sol with respect to the particle size, UV illumination, pH and electron acceptor addition. The PL spectra show that the photoinduced carriers are easy to transfer to surface in the case of small particles; the acidic environment can destroy the surface electronic structure because the surface recombination is quenched, but the bulk recombination is still clearer. The PL spectra also show that the UV illumination can obviously change surface electronic structure; the Ag+ addition can increase electron transportation to Ag+.