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 (Co<sub>3</sub>O<sub>4</sub>) thin films were successfully synthesized under open-air conditions using atmospheric pressure plasma-enhanced chemical vapor deposition (AP-PECVD) with the Co(acac)<sub>3</sub> 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 Co<sub>3</sub>O<sub>4</sub> thin films and eliminating residual impurities such as carbon and nitrogen, as demonstrated by experiments in O<sub>2</sub>-free environments. The formation of Co<sub>3</sub>O<sub>4</sub> 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 Co<sub>3</sub>O<sub>4</sub> thin films synthesized via AP-PECVD.
