Olivier Monfort

An efficient Nb-modified BiVO4 film for photo-induced bacterial inactivation and photocatalytic removal of organic pollutants

Using a Nb-modified BiVO4 film, the photo-induced properties in Methicillin-resistant Staphylococcus aureus (MRSA) inactivation under simulated solar light reached 43% after 1 hour of irradiation, while 72% of Rhodamine B was degraded after 3 hours. To evaluate the efficiency of Nb–BiVO4, its photo-performance was compared with that of BiVO4/TiO2 composites and pure BiVO4.

Bismuth vanadate-based semiconductor photocatalysts: a short critical review on the efficiency and the mechanism of photodegradation of organic pollutants

The number of publications on photocatalytic bismuth vanadate-based materials is constantly increasing. Indeed, bismuth vanadate is gaining stronger interest in the photochemical community since it is a solar-driven photocatalyst. However, the efficiency of BiVO4-based photocatalyst under sunlight is questionable: in most of the studies investigating the photodegradation of organic pollutants, only few works identify the by-products and evaluate the real efficiency of BiVO4-based materials. This short review aims to (i) present briefly the principles of photocatalysis and define the photocatalytic efficiency and (ii) discuss the formation of reactive species involved in the photocatalytic degradation process of pollutants and thus the corresponding photodegradation mechanism could be determined. All these points are developed in a comprehensive discussion by focusing especially on pure, doped, and composite BiVO4. Therefore, this review exhibits a critical overview on different BiVO4-based photocatalytic systems with their real efficiency. This is a necessary knowledge for potential implementation of BiVO4 materials in environmental applications at larger scale than laboratory conditions.

Formation of Vanadium Oxide Thin Films Prepared from Aqueous Sol-Gel System

Vanadium oxide thin films are promising materials for various applications. Much attention has been devoted to thermotropic VO2(M/R) films which exhibit semiconductor-conductor phase transition at 67 °C making them excellent materials for switching applications. Non-thermotropic VO2(B) films are semiconducting and have layered structure which makes them interesting for gas sensing applications. Vanadium pentoxide films are also of great interest for photocatalytic production of H2 by H2O decomposition as well as for gas sensing. In this paper the preparation of vanadium oxide thin films by using the spin coating of V2O5·nH2O aqueous gel on Si/SiO2 and lime-glass substrates is reported. The as-deposited films were annealed in either air or H2/Ar atmosphere at normal or low pressure in order to prepare V2O5 and VO2 thin films. The obtained samples were characterized by XRD and SEM.