Cobalt Oxide (Co3O4) Thin Films Synthesized by Atmospheric Pressure PECVD: Deposition Mechanisms and Catalytic Potential
Mallmann J., Chemin J.B., Cardenas Morcoso D., Philippe A.M., Bulou S., Chaabane N., Rouillard F., Choquet P., Boscher N.D.
ACS Applied Energy Materials, vol. 8, n° 11, pp. 7038-7051, 2025
Crystalline and electrocatalytically active cobalt oxide (Co3O4) thin films were successfully synthesized under open-air conditions using atmospheric pressure plasma-enhanced chemical vapor deposition (AP-PECVD) with the Co(acac)3 precursor. This study explored the influence of process parameters on the composition, crystallinity, and quality of the resulting thin films. It was found that the substrate temperature had a negligible effect due to the inherent heating by the plasma afterglow. The presence of atmospheric oxygen was identified as crucial for forming Co3O4 thin films and eliminating residual impurities such as carbon and nitrogen, as demonstrated by experiments in O2-free environments. The formation of Co3O4 was attributed to radical-mediated reactions, where the reactive species generated in the plasma interacted with oxygen-rich molecules from the surrounding air. These findings provide valuable insights into the deposition mechanisms and catalytic potential of Co3O4 thin films synthesized via AP-PECVD.