Plasma-engraved Co₃O₄ nanostructure toward improved formaldehyde oxidation performance: Insight into the structure–activity relationship

Improving the surface area and the number of oxygen vacancy are vital for superior catalytic oxidation performance. Here, plasma-engraved technique was used for surface modification of Co₃O₄ nanostructure (cube and sphere morphology), which was applied to formaldehyde oxidation reaction. It was found that the formaldehyde oxidation can be boosted over plasma-engraved Co₃O₄ nanostructure, and efficiently realized at room temperature. Based on varied characterizations, it revealed that the plasma-treatment endowed the Co₃O₄ nanostructure with surface reconstruction (notches and broken fragments on surface), along with high surface area and rich oxygen vacancies. These factors contribute very important effort for improved activity. Besides, surface reaction mechanism was also proposed based on the in-situ DRIFTs, during which the CHOH was transformed to key intermediates (DOM, formate and/or carbonate), and finally to CO₂ and H₂O. This study also provides a very efficient strategy for surface modification of heterogeneous solid catalyst and their expand application in environmental catalysis.