“…Nanostructured spinel cobalt(II,III) oxide has been receiving enormous attention because of its various applications in electrochemistry, catalysis, gas sensing, and batteries and energy storage. − In particular, the use of cobalt oxide as an efficient electrocatalyst for water oxidation − is of paramount importance as the water oxidation reaction is typically the key kinetic bottleneck in most electrocatalytic and photoelectrocatalytic water-splitting systems, which are currently envisaged as highly promising approaches to secure the future supply of low-cost and sustainable energy. − In general, the activity of electrocatalysts and their applicability in solar-driven water-splitting devices depends on various factors, including their composition, morphology, thickness, and optical properties. ,,,, The development of methods allowing for precisely controlled deposition of cobalt oxide films is therefore of crucial importance. Typical methods for the fabrication of cobalt oxides include sol–gel processes, − spray pyrolysis, − electrodeposition, or physical vapor deposition (PVD). − However, in terms of the precise control over the phase and thickness, these methods are outperformed by chemical vapor deposition (CVD) and atomic layer deposition (ALD) . Out of these techniques, in particular ALD represents a unique and powerful technique that is capable of depositing films with exceptional conformality, distinct morphology, and phase control on a nanometer scale , including deposition of materials over complex-shaped substrates.…”