Photocatalytic activity of titanium dioxide coatings: Influence of the firing temperature of the chemical gel

摘要: Heterogeneous photocatalysis can be exploited for the decomposition of micro-organisms which have developed on surfaces building materials. In this work, efficiency titanium dioxide coatings fired clay products is examined. The sol-gel method used to synthesize a fine TiO2 powder with specific surface area 180 m2 g−1. Thermal treatment chemical gel at 340 °C leads crystallisation in anatase phase and further temperature increase, crystallite growth. For thermal treatments range 580-800 °C, there progressive transition from rutile. However, despite decrease attributed aggregation/agglomeration, coherent domain size deduced X-ray diffraction measurements remains almost constant 23 nm. Once completed, increase above 800 growth rutile phase. thermally treated titania powders were then sprayed onto substrates photocatalytic activity was assessed by aptitude coating degrade methylene blue when exposed ultraviolet light. These tests revealed that important controlling factor rather than or anatase/rutile polymorph ratio.