Transition‐metal phosphides (TMP) prepared by atomic layer deposition (ALD) are reported for the first time. Ultrathin Co‐P films were deposited by using PH₃ plasma as the phosphorus source and an extra H₂ plasma step to remove excess P in the growing films. The optimized ALD process proceeded by self‐limited layer‐by‐layer growth, and the deposited Co‐P films were highly pure and smooth. The Co‐P films deposited via ALD exhibited better electrochemical and photoelectrochemical hydrogen evolution reaction (HER) activities than similar Co‐P films prepared by the traditional post‐phosphorization method. Moreover, the deposition of ultrathin Co‐P films on periodic trenches was demonstrated, which highlights the broad and promising potential application of this ALD process for a conformal coating of TMP films on complex three‐dimensional (3D) architectures.

Copper ferrite, belonging to the wide and technologically relevant class of spinel ferrites, was grown in the form of t-CuFe₂O₄ nanocrystals within a porous matrix of silica in the form of either an aerogel or a xerogel, and compared to a bulk sample. Extended X-ray absorption fine structure (EXAFS) spectroscopy revealed the presence of two different sub-lattices within the crystal structure of t-CuFe₂O₄, one tetragonal and one cubic, defined by the Cu²⁺ and Fe³⁺ ions respectively. Our investigation provides evidence that the Jahn-Teller distortion, which occurs on the Cu²⁺ ions located in octahedral sites, does not affect the coordination geometry of the Fe³⁺ ions, regardless of their location in octahedral or tetrahedral sites.

The control over size and shape of nanoMOFs is essential for their exploitation in integrated devices such as sensors, membranes for gas separation, photoelectrodes, etc. Here, we demonstrate the synthesis of nanowires and three-dimensionally interconnected nanowire networks of Cu-based metal-organic frameworks (MOFs) by a combination of ion-track technology and electrochemical methods. In particular, Cu nanowires and nanowire networks were electrodeposited inside polymeric etched ion-track membranes, and subsequently converted by electrochemical oxidation into different Cu-based MOFs such as the well-known Cu₃(BTC)₂ (also known as HKUST-1) and the lesser known MOF Cu(INA)₂. The MOFs are formed inside the template, therefore adopting the shape of the host nanochannels. The synthesized MOF nanowires exhibit tunable diameters between 80 and 260 nm. Characterization by XRD, TGA/DSC, SEM and TEM indicate that the employed electrochemical conversion includes the formation of Cu₂O as an intermediate, as well as the initial formation of an amorphous MOF phase, which crystallizes upon longer reaction times.