Comprehensive evolved gas analysis of amorphous precursors for S-doped titania by in situ TG–FTIR and TG/DTA–MSPart 1. Precursor from thiourea and titanium(IV)-isopropoxide

Decomposition of an amorphous precursor for S-doped titania (TiO2) nanopowders, prepared by controlled sol–gel hydrolysis–condensation of titanium(IV) tetraisopropoxide and thiourea in aqueous isopropanol, has been studied up to 800°C in flowing air by simultaneous thermogravimetric and differential thermal analysis coupled online with quadrupole mass spectrometer (TG/DTA–MS) and FTIR spectrometric gas cell (TG–FTIR) for analysis of gases and their evolution dynamics (by evolved gas analysis, EGA) in order to explore and model thermal annealing processes of fabrication techniques leading to S:TiO2 photocatalysts with photocatalytic activities under visible light.