Properties of Mechanochemically Synthesized Famatinite Cu3SbS4 Nanocrystals

In this study, we report the optoelectric and thermoelectric properties of famatinite Cu3SbS4 that was mechanochemically synthesized in a planetary mill from powder elements for 120 min in an inert atmosphere. The tetragonal famatinite Cu3SbS4 was nanocrystalline with a crystallite size of 14 nm, as endorsed by Rietveld refinement. High-resolution transmission electron microscopy showed several crystallites in the range of 20–50 nm. Raman spectroscopy proved the purity of the synthesized famatinite Cu3SbS4 and chemical-state characterization performed by X-ray photoelectron spectroscopy confirmed that the prepared sample was pure. The Cu1+, Sb5+, and S2− oxidation states in Cu3SbS4 sample were approved. The morphology characterization showed homogeneity of the prepared sample. The photoresponse of Cu3SbS4 was confirmed from I–V measurements in the dark and under illumination. The photocurrent increase reached 20% compared to the current in the dark at a voltage of 5 V. The achieved results confirm that synthesized famatinite Cu3SbS4 can be applied as a suitable absorbent material in solar cells. The performed thermoelectric measurements revealed a figure of merit ZT of 0.05 at 600 K

Leaching of Silver from Mechanically Activated Naumannite

In this paper, the structure, morphology, chemical composition and leaching of naumannite (Ag2Se) were studied. Mechanical activation of Ag2Se in a planetary ball mill resulted in increasing its specific surface area. The influence of milling time on the particle size was studied by particle size distribution analysis and scanning electron microscopy. The leaching kinetics of non-activated and mechanically activated samples in 3.5–7.9 mol/L HNO3 solutions were examined. Subsequently, the effect of leaching temperature in the range of 25–50°C on the recovery of silver from mechanically activated naumannite was documented. The maximum yield of silver 94% was achieved after 120 min of leaching in 7.9 mol/L HNO3 at 50°C for the sample mechanically activated for 30 min. Based on calculated activation energy values from the Arrhenius equation, a mixed leaching mechanism consisting of diffusion and surface chemical reaction as the rate-controlling steps of the solid-liquid reaction was assessed.Fil: Gáborová, Katarína. Slovak Academy of Sciences. Institute of Botany; EslovaquiaFil: Achimovičová, Marcela. Slovak Academy of Sciences. Institute of Botany; EslovaquiaFil: Skácha, Pavel. No especifíca;Fil: Marquez Zavalia, Maria Florencia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza. Instituto Argentino de Nivología, Glaciología y Ciencias Ambientales. Provincia de Mendoza. Instituto Argentino de Nivología, Glaciología y Ciencias Ambientales. Universidad Nacional de Cuyo. Instituto Argentino de Nivología, Glaciología y Ciencias Ambientales; ArgentinaFil: Briančin, Jaroslav. Slovak Academy of Sciences. Institute of Botany; EslovaquiaFil: Sestinová, Oľga. Slovak Academy of Sciences. Institute of Botany; Eslovaqui