Mesoporous TiO2-WO3 thin films for photocatalysis

Titania (TiO₂) is widely studied for its photocatalytic properties, with applications in self-cleaning surfaces and water purification. This thesis focuses on the synthesis of mesoporous titania nanofilms using a self-assembly mechanism with a templating agent and investigates the effect of tungsten oxide (WO₃) addition to enhance photocatalytic activity. Three precursor routes for tungsten synthesis—tungstic acid, metallic tungsten, and sodium tungstate—were explored. Sodium tungstate and metallic tungsten yielded the best results, while tungstic acid presented deposition challenges. Thermal treatments at 350°C and a rapid crystallization method (350°C for 1 hour, followed by a rapid increase to 700°C) revealed significant temperature-dependent differences. Films treated at 350°C exhibited well-ordered porosity, whereas 700°C treatments resulted in higher crystallinity. Photocatalytic tests demonstrated that tungsten doping enhanced activity at levels up to 3%, but excessive amount reduced performance. Higher temperatures (700°C) improved photocatalytic efficiency due to the transition from amorphous to anatase phase.