Titanium dioxide, TiO2, is an important photocatalytic material that exists as two main polymorphs, anatase and rutile. The presence of either or both of these phases impacts on the photocatalytic performance of the material. The present work reviews the anatase to rutile phase transformation. The synthesis and properties of anatase and rutile are examined, followed by a discussion of the thermodynamics of the phase transformation and the factors affecting its observation. A comprehensive analysis of the reported effects of dopants on the anatase to rutile phase transformation and the mechanisms by which these effects are brought about is presented in this review, yielding a plot of the cationic radius versus the valence characterised by a distinct boundary between inhibitors and promoters of the phase transformation. Further, the likely effects of dopant elements, including those for which experimental data are unavailable, on the phase transformation are deduced and presented on the basis of this analysis.

https://link.springer.com/content/pdf/10.1007%2Fs10853-010-5113-0.pdf

Review of the anatase to rutile phase transformation

Electroactive phases of poly(vinylidene fluoride) : determination, processing and applications

Progress in the production and modification of PVDF membranes

Applications of nanotechnology in water and wastewater treatment

Asymmetric multicomponent reactions involve the preparation of chiral compounds by the reaction of three or more reagents added simultaneously. This kind of addition and reaction has some advantages over classic divergent reaction strategies, such as lower costs, time, and energy, as well as environmentally friendlier aspects. All these advantages, together with the high level of stereoselectivity attained in some of these reactions, will force chemists in industry as in academia to adopt this new strategy of synthesis, or at least to consider it as a viable option. The positive aspects as well as the drawbacks of this strategy are discussed in this Review.

Asymmetric multicomponent reactions (amcrs): the new frontier

Characterization of PVDF membranes by vibrational spectroscopy

FT Raman and FTIR/FTFIR skeletal spectra of different TiO2 powders, of both synthetic and commercial origin, and of Sr, Ba, Co and Ni metatitanates are reported and discussed in relation to the predictions of factor group analyses. The ability of vibrational techniques to show the presence of brookite impurities in both anatase and rutile, and of rutile in anatase, as well as to give morphological and surface information is emphasized. The spectra of SrTiO3, BaTiO3, NiTiO3 and CoTiO3 are also discussed in relation to their different structures (pervoskite and ilmenite-type).

FT Raman and FTIR studies of titanias and metatitanate powders

Preparation and properties of novel organic–inorganic porous membranes

Mixed oxide powders belonging to the system CdMoxW1-xO4 have been prepared by a hydrothermal method. They have been characterized by the Rietveld analysis of their XRD patterns and by IR and Raman skeletal spectroscopies. Virtually pure wolframite-type structures have been obtained for x ≤ 0.25 and virtually pure scheelite-type structures have been obtained for x ≥ 0.75. The vibrational spectra of both phases have been interpreted on the basis of the correlation method. In both solid solutions the Raman peaks due to the stretching modes of “terminal” W,Mo−O bonds split, while the corresponding IR bands shift significantly. The effect of the nature of tungsten coordination on the vibrational spectra is briefly discussed in relation to the use of vibrational spectroscopies to determine the structure of the surface species in supported tungsten oxide catalysts.

Paolo Piaggio

Papers

Characterization of PVDF membranes by vibrational spectroscopy

FT Raman and FTIR studies of titanias and metatitanate powders

Preparation and properties of novel organic–inorganic porous membranes

Vibrational and XRD Study of the System CdWO4−CdMoO4

Poly(vinylidene fluoride) with improved functionalization for membrane production