A cobalt(ii)heteroarylalkenolate precursor for homogeneous Co₃O₄ coatings by atomic layer deposition

We present a new and efficient cobalt precursor, Co^II(DMOCHCOCF₃)₂, to prepare Co₃O₄ thin films and conformal coatings. In the synthesis of this Co complex, heteroaryl moieties and CF₃-groups were combined leading to the precursor with high thermal stability and volatility. The suitability of this precursor for ALD deposition was tested on flat silicon substrates and TiO₂/C nanofibers upon process optimization. Deposition at 200 °C results in homogeneous and smooth Co₃O₄ thin films with a growth rate of 0.02 nm per cycle. Conformal coatings have been successfully obtained on TiO₂/C nanofibers, making them an attractive platform for surface chemistry studies on high aspect ratio structures for future photocatalysts, sensors, supercapacitors and batteries.