Bulk and Thin Films of Bismuth Vanadates Prepared from Hybrid Materials Made from an Organic Polymer and Inorganic Salts

A new precursor route for the preparation of bulk oxides and thin films of bismuth vanadates is proposed. The method involves the thermal treatment under air and mild conditions of hybrid organic−inorganic precursors, made from a zwitterionic salt-free polymer matrix and selected inorganic species. Monoclinic BiVO4 was obtained in the form of bulk oxide by calcination of the powdered homogeneous hybrid materials at 600 °C, from precursors containing Bi and V in stoichiometric amounts. In the same way, thermodiffractometry studies performed on a hybrid material exhibiting a Bi/V molar ratio of 2 revealed that the ionic conductor γ-Bi4V2O11 phase can be stabilized under very soft thermal conditions (300 °C). Additionally, thin films of yellow monoclinic BiVO4 were for the first time fabricated, by thermal treatment of the same hybrid polymeric precursors deposited on quartz substrates by spin coating, using a layer-by-layer technique. The presence of the target phase at the surface of the plates was confirmed by X-ray diffraction as well as UV−vis measurements.