Pulse-reverse electrodeposition of multi-layered lead films: Influence of deposition time and current density on microstructure, electrochemical properties, and applications in zinc electrowinning

This work explores the influence of current density and deposition time on the morphological and electrochemical characteristics of electrodeposited lead films based on lead acetate (Pb (CH 3 COO) 2 ) and ammonium acetate (NH 4 (CH 3 COO) 2 ) via Pulse reverse electrodeposition method. Deposition was performed at 20 and 40 A/m 2 for different durations. The formation, morphology, electrical resistance and Electrochemically Active Surface Area (ECSA) of deposited cathodic Pb were evaluated by Scanning Electron Microscope (SEM) observation and Electrochemical Impedance Spectroscopy (EIS) analysis, respectively. At higher current densities (40 A/m 2 ), rapid nucleation and growth produced uniform lead structures within 3 h, while lower current densities required extended deposition to achieve similar coverage. Electrical resistance measurements revealed a decrease with increasing deposition time up to 24 h, enhancing charge transport due to improved layer connectivity. The 24-h sample at 40 A/m 2 exhibited the lowest resistance (2.30Ω) and highest electrochemically active surface area (ECSA) (11.584 1/cm 2 ), making it the optimal condition. However, deviations were observed at 3 h (due to partial silver substrate exposure) and at 48 h (due to void formation and surface roughness), both of which impaired conductivity. These results demonstrate the critical role of deposition parameters in modifying lead film properties for electrochemical applications, offering insights into optimizing electrodeposition processes for use in energy-related technologies.