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A family of Metal–Organic Frameworks (MOFs) based on the ligands pyrazine (pyz) and dicyanamide (dca) and the metal centers Fe, Co and Ni with the unit formula M(dca)2pyz has been studied as anodes for Li-Ion Batteries (LIBs). These compounds are analogs of transition metal nitrides (TMNs) but synthesized following an environmentally friendly process. Fe(dca)2pyz provides the best electrochemical performance with a specific capacity of 519 mA h g−1 and 375 mA h cm−3 after 450 cycles at 200 mA g−1 and a capacity retention of 90% with respect to the first cycle. This performance is better than most of the Fe nitrides reported to date, highlighting its potential as an anode for LIBs. The high capacity is due to the conversion and displacement reaction occurring with the Fe atoms and the insertion of Li+ into the ligands. In contrast, the specific capacities of Co(dca)2pyz and Ni(dca)2pyz are lower due to a partial reduction of the Co atoms in the first case, and to the oxidation of the Ni atoms which hinders the Li+ intercalation process in the second. As a result, the specific capacities after 450 cycles at 200 mA g−1 are 148 mA h g−1 for Co(dca)2pyz and 57 mA h g−1 for Ni(dca)2pyz. Powder-XRD and TEM characterizations after cycling of the three samples reveal that Fe(dca)2pyz and Co(dca)2pyz samples become amorphous while the Ni(dca)2pyz material does not. This suggests that the amorphization process is relevant for obtaining anodes with improved electrochemical performance. This study demonstrates that MOFs obtained by a cost-effective and environmentally friendly method can act as precursors for obtaining high performance anodes for LIBs without the need for an energy intensive carbonization process, since they undergo an in situ amorphization process, giving rise to AMorphous Organometallic (AMO) electrodes. [ABSTRACT FROM AUTHOR]

Herein, we show how electron microscopy can provide atomic-level understanding of FAPbBr3, where electron diffraction and high-resolution imaging were combined allowing not only the characterization of the pristine material but also the identification of different intermediates upon its structural disintegration. Additionally, a minor tetragonal phase was also identified whose structure was also solved. [ABSTRACT FROM AUTHOR]

Herein, we show how electron microscopy can provide atomic-level understanding of FAPbBr3, where electron diffraction and high-resolution imaging were combined allowing not only the characterization of the pristine material but also the identification of different intermediates upon its structural disintegration. Additionally, a minor tetragonal phase was also identified whose structure was also solved. [ABSTRACT FROM AUTHOR]

Thermal atomic layer deposition (TALD) and plasma atomic layer deposition (PALD) were used for producing thin NiO x films from nickel(II) acetylacetonate Ni(acac) 2 , employing different oxidizing agents (deionized water H 2 O, ozone O 3 , and molecular oxygen O 2 ). The films were deposited at 300 °C (TALD) and 220 °C (PALD) over glass substrates; their physical and chemical properties were considerably influenced by the choice of oxidizing agents. In particular, ALD(H 2 O) samples had a low growth per cycle (GPC) and a high concentration of defects. The best NiO x parameters were achieved with PALD(O 2 ), featuring high GPC (0.07 nm/cycle), high optical transparency in the visible region, electrical resistivity (1.18 × 10 4 Ω·cm), good carrier concentration (8.82 × 10 13 cm -3 ), and common mobility (5.98 cm 2 /V·s). The resulting NiO x films are polycrystalline and homogeneous in thickness and composition. According to ultraviolet photoelectron spectroscopy (UPS), work function φ and the valence band maximum E V can be tuned by the choice of the coreactant employed, with variations of up to ∼1 eV between TALD and PALD synthesis. Our results suggest that PALD permits one to achieve a better energy band alignment of NiO x and CsFAMAPbBrI perovskite, which is promising for solar cell applications., Competing Interests: The authors declare no competing financial interest., (© 2024 The Authors. Published by American Chemical Society.)