Effect of Nb(V) doping on the Structure and Oxygen Chemisorption on Nanocrystalline TiO2

This work is devoted to the study of the effect of niobium doping on the structural characteristics and chemisorption of oxygen on the TiO2 surface. Pure and Nb doped TiO2 was obtained by flame spray pyrolysis and characterized using SEM, TEM, XRD, low‐temperature nitrogen adsorption XRF, XPS, TPR‐H2 methods. The introduction of niobium stabilizes the anatase phase, increases the specific surface area of TiO2 and the concentration of chemisorbed oxygen. By in situ conductivity measurements depending on the oxygen partial pressure, it is shown that an increase in the Nb concentration leads to the growth of the fraction of chemisorbed oxygen with a lower effective charge. The heterovalent Nb(V) doping leads to the following changes in the properties of nanocrystalline TiO2: (i) increase in the specific surface area; (ii) stabilization of the anatase phase; (iii) increase in total concentration of chemisorbed oxygen on the TiO2 surface accompanied by the growth of the fraction with a lower effective negative charge.