Non-aqueous metathesis as a general approach to prepare nanodispersed materials: Case study of scheelites

P. Afanasiev (1)

1 CATREN - IRCELYON-Catalyse Hétérogène pour la Transition Energétique

A general approach to the preparation of inorganic nanoparticles is proposed, using metathesis of precursor salts in non-aqueous liquids. Nanoparticles of scheelites AMO(4) (A=Ba, Sr, Ca; M=Mo, W), were obtained with a quantitative yield. Precipitations in formamide, N-methylformamide, propylene carbonate, DMSO and polyols often provide narrow particle size distributions. Advantageous morphology was explained by strong ionic association in non-aqueous solvents, leading to slow nucleation and negligible Ostwald ripening. Mean particle size below 10 nm and high specific surface areas were obtained for several Ca(Sr)Mo(W)O-4 materials, making them promising for applications as adsorbents or catalysts. Zeta-potential of scheelites in aqueous suspensions showed negative values in a wide range of pH. Systematic study of optical properties demonstrated variation of optical gap in the sequences W > Mo and Ba > Sr > Ca. The observed trends were reproduced by DFT calculations. No quantum confinement effect was observed for small particles, though the surface states induce low-energy features in the optical spectra. (C) 2015 Elsevier Inc. All rights reserved.

Domaines: Catalyse; Environnement et Société

P. Afanasiev. Non-aqueous metathesis as a general approach to prepare nanodispersed materials: Case study of scheelites. Journal of Solid State Chemistry, 2015, 229, pp.112-123. ⟨10.1016/j.jssc.2015.05.006⟩. ⟨hal-01198956⟩