Preparation of titania-based catalysts for formaldehyde photocatalytic oxidation from TiCl4 by the sol–gel method

The valence and site occupancy of substituting metals in magnetite spinel structure Fe3−xMxO4 (M = Cr, Mn, Co and Ni) and their influence on thermal stability: An XANES and TG-DSC investigation

“…This suggests that the incorporation of these metal cations increases the surface hydroxyl amount. The surface hydroxyl groups are functional groups of iron oxides due to its vital role in surface adsorption [49], photocatalysis [50] and surface acidity (Br4nsted acid) [51]. Under dry conditions, surface Fe cations may be unsaturated in coordination.…”

A comparative study about the effects of isomorphous substitution of transition metals (Ti, Cr, Mn, Co and Ni) on the UV/Fenton catalytic activity of magnetite

“…For substituted magnetite samples, both the broadening of diffraction lines at ca. [28][29][30][31][32][33][34][35][36][37][38][39] • and the shift of peaks at ca. 35.5 • toward lower diffraction angle indicate the incorporation of substituting metals into inverse spinel structure, which is resulted from the difference in ionic radii between iron and substituting metal cations (Table 1) [21].…”

“…The surface hydroxyl groups are functional groups of iron oxides, due to its vital role in surface adsorption [37], photocatalysis [38] and surface acidity (Brønsted acid) [39]. The incorporation of substituting metals resulted in a slight distortion of magnetite lattice and accordingly increased the surface hydroxyl amount [40].…”

Effects of peptizing conditions on nanometer properties and photocatalytic activity of TiO2 hydrosols prepared by H2TiO3

“…It was found the minimum crystallite size was -9 - oxolation bonds among titanium atoms were broken and the rates of nucleation and crystal growth was changed [34,35]. This also implied that there was an optimal H + /Ti (0.75) with the smallest particle size (26.3 nm).…”