Guido Mul (UT)

In this presentation I will discuss how material properties and process conditions affect the performance of SrTiO3 in photocatalytic oxidation of acetone, a compound representative of pollutants typically present in indoor environments. First I will focus on the impact of Al3+ doping on the surface chemistry of well-structured, faceted SrTiO3, comparing in situ  infrared spectra of pristine and Al-doped samples. While pristine SrTiO3 exhibits facet-dependent adsorption behavior consistent with variations in surface coordination environments, we show that Al3+ incorporation suppresses these distinctions and leads to convergent acetone adsorption states across different morphologies. More importantly, photocatalytic oxidation of acetone terminates at adsorbed carboxylates and carbonates, showing that Al-doping prohibits complete mineralization of hydrocarbons.

We have used Design of Experiments (DoE) to identify “sweet spots” in process variables under realistic environmental (indoors) conditions, focusing on humidity and light intensity, and including two morphologies of SrTiO3 (STO): cubic (c-STO) and {110}-truncated (trd-STO). trd-STO outperformed cubic-STO, exhibiting high reaction rates in a broad optimum range, greater stability, and superior light efficiency under conditions of high humidity. I will demonstrate that DoE is a powerful tool for identifying “sweet spots” in VOC photomineralization and to reveal how surface facet engineering impacts photocatalytic behavior under realistic environmental conditions.