*2.2. Characterization of Photocatalysts*

The synthesized solids were micro-structurally characterized using: X-ray diffraction (XRD), Fourier Transformed Infrared Spectroscopy (FTIR), Raman spectroscopy, and transmission electron microscopy (TEM). To perform the IR spectroscopy analysis, the solid was homogenized with spectroscopic grade potassium bromide (99%, Fischer, Pittsburgh, USA) in an agate mortar. The mixture was subjected to pressure through a 318 stainless steel die until forming a translucent pellet. The sample was analyzed with a Nicolet IR-200 infrared spectrophotometer equipped with EZOMINIC 32 software. A total of 32 scans were conducted at a resolution of 16 cm<sup>í</sup><sup>1</sup> /s. For the XRD study of the powder samples, a PANalytical X'Pert Pro X-ray diffractometer was used with Bragg Brentano geometry, equipped with CuKĮ (Ȝ = 1.5406 Å) radiation source, operating with 45 mA current and voltage of 45 kV. Powder X-ray diffraction patterns (PXRD) were registered within the 1 to 10° interval, as well as between 10° and 70°, in 2ș, at 0.5 °/min scan rate. The samples were observed with transmission electron microscopy (Jeol 1200 EX, JEOL, Pleasanton, CA, USA) with an electron beam electric potential acceleration of 80 kV. Raman spectra were obtained through EZRaman-N and ProRaman-L-905 (Enwave Optronics, Irvine, USA) Raman analyzers coupled to a Leica DM300 microscope (with a Leica objective that has a magnification/numerical aperture ratio of 40×/0.65), using excitation laser sources of 905 nm (maximum power ̱400 mW). The adsorption/desorption of nitrogen was carried out at í196 °C in a Micromeritics ASAP 2010 (micromeritics, USA). The samples were previously treated under high vacuum at 150 °C for 12 h. Finally, elemental composition was determined by SEM-EDX in a Stereoscan 440 Leica microscope (Leica Microsystems, Mannheim, Germany) equipped with an energy dispersive X-ray (EDX) elemental analysis system.
