*3.3. (Photo)catalytic Experiments*

The photocatalytic tests were performed utilizing a solar lamp (OSRAM Vitalux 300 W, 300–2000 nm, OSRAM Opto Semiconductors GmbH, Leibniz, Regensburg Germany) irradiating a jacketed Pyrex batch reactor, kept at 25 ◦C. A total of 50 mg of powder was suspended in 50 mL of the reactant solution containing 5×10−<sup>5</sup> M of IMI (Sigma-Aldrich, Buchs, Switzerland). The reaction mixture was stirred for 120 min in the dark so as to achieve the adsorption/desorption equilibrium. During the tests, aliquots of the suspension were withdrawn at a given time interval to measure the IMI concentration by means of Cary 60 UV–vis spectrophotometer (Agilent Stevens Creek Blvd. Santa Clara, United States). The IMI degradation was evaluated by following the absorbance peaks at 270 nm in the Lambert–Beer regime, reporting the *C*/*C<sup>0</sup>* ratio as a function of time *t*, where *C* is the concentration of the contaminant at the time *t*, while *C<sup>0</sup>* is the starting concentration of the pollutant. The Fenton-like reaction was carried out with the same apparatus described above, adding 5 mL of hydrogen peroxide (3%, 0.9 M Fluka, Buchs, Switzerland) in the reactor without irradiation; in the photo-Fenton-like tests the solar light irradiation was employed, too. In all the catalytic tests the experimental error was 1%, i.e., within the symbol size.
