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Preparation and characterization of a new TiO2/SiO2 composite catalyst for photocatalytic degradation of indigo carmin

“…to be around 16 nm, in agreement with data in the literature for Degussa P25 titanium dioxide (Danion 2004). The rutile content was very small in our starting P25 material (2% instead of 35% in the usual Degussa P25 sample) (Girot et al 2002), so that it was hardly visible in the XRD pattern of our TiO 2 -SiO 2 catalyst.…”

Direct synthesis of A2(Ti(1−y)Zry)2O7 (A=Gd3+, Y3+) solid solutions by ball milling constituent oxides

“…Although complete transformation is not observed in our case, both polymorphs seem to coexist after the first hour as evidenced by the presence of a group of weak reflections in a region, between 28 • and 33 • (2θ), where the characteristic peaks of the monoclinic form are found [8]. High-energy ball milling is also known to induce the polymorphic transformation of anatase TiO 2 , first, into a transient high-pressure orthorhombic form having the ␣-PbO 2 structure, TiO 2 -II, and with increasing milling time, into tetragonal rutile [9,10]. However, the existence of such transformations cannot be observed with the experimental settings chosen in this work.…”

Mechanochemical preparation of nanocrystalline TiO2 powders and their behavior at high temperatures

“…One group of authors [8][9][10] induced the phase transition in the starting TiO 2 using a high-energy planetary ball-mill with various milling tools and different powder-to-ball weight ratios (R). These authors observed that R influenced only the rate of phase transition in TiO 2 , if other parameters were constant.…”