Formation Mechanism of Electrodeposited Sb/Sb2O3 Micro-Composites

Antimony (Sb) and antimony oxide have (Sb2O3) gained attention in research and industry in recent years because of their potential use in secondary batteries and as materials for sensor applications. As shown in recent studies, Sb/Sb2O3 composites with different nanostructures and compositions can be fabricated by a straightforward electrochemical deposition process. In the present work the nucleation and growth mechanism of Sb/Sb2O3 composites is investigated by means of electrochemical and chemical methods combined with electron microscopy and X-ray diffraction. A local pH shift, caused by the electrodeposition of Sb and leading to the co-deposition of Sb2O3, is verified experimentally for the first time. The Sb nucleation mechanism is investigated by fast transient measurements. The formation of Sb2O3 is examined by titration with KOH. Based on the results, a nucleation and growth model is proposed that explains the development of different Sb/Sb2O3 structures and compositions depending on the applied electrochemical process parameters.