Inkjet printing of photocatalytically active TiO2 thin films from water based precursor solutions

In this work, aqueous chemical solution deposition route suited for inkjet printing is used for the synthesis of photocatalytically active TiO2 coatings. Environmentally friendly precursor solutions with electromagnetic ink-jet printing, allows cheap and simple processing of TiO2 films on glass. The hydrolysis reaction of water sensitive titanium alkoxide (Ti-alkoxide) precursor is controlled by adding complexing agents as citric acid and triethanolamine prior to water addition, and aqueous stable solutions are achieved. The pH of the solutions is brought to neutral to guarantee flexible processing, avoid damage to substrates and equipment. Solution parameters are adapted to obtain optimal gelation conditions and good jettability. The influence of processing parameters on the phase formation and surface morphology is studied by thermogravimetric analysis and differential thermal analysis (TGA/DTA), X-ray diffraction (XRD), scanning electron microscopy (SEM) and atomic force microscopy (AFM). The photocatalytic activity of the films is evaluated by the degradation of methyl orange.