The synthesis of Pac-Man like particles is described in detail in previous publications. Briefly, 4.57 w/v % of Pluronic P123 (Mn = 5800 g mol -1 , Sigma-Aldrich (Germany)) is taken in a 35 mL solvent mixture of acetic acid (100%, VWR chemicals (Germany)), hydrochloric acid (37 wt%, VWR chemicals (Germany)), and tetrahydrofuran (≥ 99.9%, Riedel-de Haën (Germany)) in volume ratio of 0.057:0.086:0.857. Following dissolution of the polymer in the solvent mixture, 3 mL of Titanium (IV) butoxide (97%, Sigma-Aldrich (Germany)) and 200 µL of DI water are added dropwisely with continuous stirring. This solution is heated in a water bath at 40 • C for 24 h to obtain a transparent gel. 2 g of this gel is weighed in a 50 mL Teflon vessel and autoclaved at 70 • C for 24 h. The obtained white precipitate is washed with methanol, dried and calcined at 350 • C for 3 h in a N 2 atmosphere, followed by