Variations of electronic properties on the behavior of visible light-triggered TiO2 + Au photocatalysts

• The shape of the TiO 2 support influences the catalytic activity. • TiO 2 + Au with a lower SBH shows a higher activity under visible-light illumination. • Superoxide anion radicals are the most important ROS for the degradation of BPA. • The oxygen reduction reaction does not take place at higher SBH between TiO 2 and Au. • The ferromagnetic character of Au affects the behavior of the TiO 2 + Au catalysts. In this study, we investigated the influence of TiO 2 supports on the structural and catalytic properties of TiO 2 + Au catalysts (1 wt% Au) using anatase TiO 2 nanorods (TNR, S BET = 106 m 2 /g) or nanospheres (TNP, S BET = 86 m 2 /g). The majority of Au particles in the prepared TiO 2 + Au catalysts were in the range of 20–30 nm, with slight differences observed between the TNR + Au and TNP + Au samples. It is noteworthy that the addition of Au did not significantly change the specific surface area and crystallinity of the TiO 2 supports. Evaluation of photocatalytic activity using ABTS •+ cation oxidation, DMPO/DMSO spin trapping and bisphenol A (BPA) degradation under visible-light illumination showed different behaviour of TNR + Au and TNP + Au catalysts. The TNR + Au catalyst produced mainly e - , while the TNP + Au catalyst exhibited efficient O 2 •- production, which was confirmed by electron paramagnetic resonance spin trapping analyses. Conversely, due to its high Schottky barrier height (SBH) and the properties of the Au nanoparticles, the TNR + Au catalyst could not facilitate an oxygen reduction reaction but effectively produced e - as it reduced ABTS •+ . The results show that the degradation of BPA in the presence of the TNR + Au photocatalyst occurs through the involvement of e - and a small amount of hydroxyl radicals (OH • ). Comprehensive characterization techniques provided insights into the intricate relationships between catalyst structure, composition and catalytic activity.