In the paper spent coffee grounds were used as a precursor to obtain activated carbons. The raw material was impregnated with phosphoric acid(V) at the different impregnations ratios: 0.5, 1, 1.5, 2. Carbonization was carried out according to two procedures differing in activation atmosphere (N 2 or CO 2). The obtained activated carbons were characterized on the basis of low-temperature nitrogen adsorption/desorption, thermal analysis, potentiometric titration method, X-ray diffraction, Raman spectroscopy and scanning electron microscopy. Carbons obtained according to procedure 2 (activation in CO 2) were characterized by better developed porosity, e.g. surface (S BET to 720.9 m 2 /g) and pore volume (V p to 0.334 cm 3 /g). All obtained carbons had surface acidic (mainly carboxyl) groups and exhibited the amorphous structure. The thermal analysis showed that the obtained materials were thermally stable up to the temperature ~ 420 °C.

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The formation of hierarchical, multimodal porosity materials with controlled shape and size of pores is the essential challenge in materials science. Properties of silica materials depend largely on different features: crystal structure, dispersity, surface composition, and porosity as well as the method of preparation and possible modification. In this paper, multimodal silicas obtained using different additives are presented. A-50 and A-380 aerosils and wide-porous SiO 2 milled at 300 rpm were used as the additives in the sol stage at 20 • C, the sol-gel stage followed by hydrothermal modification (HTT) at 200 • C, or in the mechanochemical treatment (MChT) process. The characterizations were made by application of N 2 adsorption/desorption, SEM imaging, quasi-isothermal thermogravimetry (Q-TG), dynamic thermogravimetry/derivative thermogravimetry/differential thermal analysis (TG/DTG/DTA), and cryoporometry differential scanning calorimetry (DSC) methods. Results showed that such a one-step preparation method is convenient and makes it possible to obtain multimodal silicas of differentiated porous structures and surface chemistry.

In the study the mechanochemical synthesis was used to prepare photocatalytic materials based on TiO2, SiO2, and Fe2O3. During the preparation the impact of composition, milling speed, and calcination process on the properties of the composites was investigated. The structural and thermal properties of photocatalysts were determined using the N2 adsorption/desorption, XRD, and FT-IR/PAS methods. The thermal stability of the obtained materials was also examined (TG/DTG). Moreover, their photocatalytic activity was tested in relation to Methylene Blue at UV and Vis radiation. The results indicate that the mechanochemical synthesis in the high-energy planetary mill is an effective method for obtaining materials with photocatalytic properties at the UV and Vis radiation. It was shown that the removal process of MB may be described by the pseudo-first-order kinetics.