Systematic variation of preparation time, temperature, and pressure in hydrothermal synthesis of macro-/mesoporous TiO2 for photocatalytic air treatment

Publication date: Available online 21 April 2019Source: Journal of Photochemistry and Photobiology A: ChemistryAuthor(s): Alireza Haghighat Mamaghani, Fariborz Haghighat, Chang-Seo LeeAbstractA series of porous TiO2 photocatalysts are prepared, by systematically varying the preparation conditions (time, temperature, or pressure (i.e. filling ratio)), characterized, and evaluated in photocatalytic oxidation of toluene and methyl ethyl ketone (MEK) to explore preparation-property-performance relationships. A detailed characterization has been conducted via X-ray diffraction (XRD), N2 adsorption-desorption, scanning electron microscopy (SEM), transmission electron microscopy (TEM), Fourier transform infrared (FTIR), and UV-vis spectroscopy. Furthermore, hydroxyl radical (•OH) generation on the surface of TiO2 is measured by a photoluminescence (PL) method using terephthalic acid (TA) as probe molecule. All the hydrothermally-prepared samples possessed good crystallinity (79.5-89 %), large surface area (134.9-237.2 m2/g), small crystal size (5.9-10 nm), and mesoporous structure. SEM images revealed presence of macropores and marcochannels, and N2 adsorption-desorption and TEM analyses indicated a significant amount of mesopores. PL and XRD results demonstrated a good proportionality between surface area normalized •OH generation and crystallinity. The complex interplay among various properties (especially crystallinity and surface area) led to appearance of activity optim...

Source: Journal of Photochemistry and Photobiology A: Chemistry - April 22, 2019 Category: Chemistry Source Type: research