Inorganic Photocatalytic Enhancement: Activated RhB Photodegradation by Surface Modification of SnO2 Nanocrystals with V2O5-like species

SnO2 nanocrystals were prepared by precipitation in dodecylamine at 100°C, then they were reacted with vanadium chloromethoxide in oleic acid at 250°C. The resulting materials were heat-treated at various temperatures up to 650°C for thermal stabilization, chemical purification and for studying the overall structural transformations. From the crossed use of various characterization techniques, it emerged that the as-prepared materials were constituted by cassiterite SnO2 nanocrystals with a surface modified by isolated V(IV) oxide species. After heat-treatment at 400°C, the SnO2 nanocrystals were wrapped by layers composed of vanadium oxide (IV-V mixed oxidation state) and carbon residuals. After heating at 500°C, only SnO2 cassiterite nanocrystals were obtained, with a mean size of 2.8nm and wrapped by only V2O5-like species. The samples heat-treated at 500°C were tested as RhB photodegradation catalysts. At 10-7M concentration, all RhB was degraded within 1h of reaction, at a much faster rate than all pure SnO2 materials reported until now.