*Maja Koblar^1,3, Sandra Drev¹, Bojan Ambrožič¹, Špela Trafela^1,3, Gavrilo Sekularac⁴, Kristina Rožman Žužek^1,3, Sašo Šturm^1,3, Miran Čeh^1,3
1Jozef Stefan Institute, Ljubljana, Slovenia; ²Institute for Chemistry, Technology, and Metallurgy, Belgrade, Russia; ³Jožef Stefan International Postgraduate School, Ljubljana, Slovenia
Understanding the phenomenon of electrochemical deposition of metals from solutions is important for the processing of thin films. In-situ TEM analytical techniques using unique specimen holders with micro-electro-mechanical systems chip design (MEMS) comprising a three-electrode system for electrochemical studies, allow us to perform an in-situ investigation of dynamic processes of nucleation process and film growth during electrochemical deposition. Ni thin nanostructured films can be readily used as catalytic or/and sensor materials as well as for protective coatings. In our work, we studied electrochemical deposition of Ni from 1 mM and 5 mM NiSO₄ aqueous solutions under varying electrochemical potential between the Pt working electrode and the Pt pseudo reference electrode. Our results showed that Ni deposition from 1 mM NiSO₄ aqueous solutions resulted in nucleation and formation of dendritic metal Ni films while higher Ni concentration in solution, i.e. 5 mM, yielded uniform Ni metal film on work electrode.