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The large‐scale application of water electrolysis, for clean H2 production, requires the development of eco‐friendly and low‐cost electrocatalysts with high activity for hydrogen evolution reaction (HER) in alkaline media. The excellent alternatives to the benchmark noble metal‐based HER electrocatalyst are transition metal oxides (TMO). Because of the nontoxicity, cost‐effectiveness, availability, and easy electronic structure tuning, zinc oxide (ZnO) is a good TMO candidate. However, ZnO shows poor performance for HER electrocatalysis and therefore has been much less reported. Herein, it is reported that ZnO can be developed as a good HER electrocatalyst in alkaline media through simultaneously proper cobalt loading at the precursor level (coordination polymer) and defects engineering. The optimum amount of cobalt in ZnO shows an overpotential of 385 mV at 10 mA cm−2 (lower than that of ZnO and Co3O4) and a small Tafel slope of 76 mV dec−1. The introduction of cobalt at the precursor level and subsequently in the wurtzite frame of ZnO as revealed by the analyses, allows to considerably lower the bandgap and increasing the number of defects in the structure, thereby boosting the electrocatalytic performance. This work highlights the potential of cheap and environmentally friendly TMO as alternative HER electrocatalysts for large‐scale alkaline water electrolysis. [ABSTRACT FROM AUTHOR]

An extensive thermodynamic study of N-methylformamide (CAS RN: 123-39-7) and N,N-dimethylformamide (CAS RN: 68-12-2), is presented in this work. The liquid heat capacities of N-methylformamide were measured by Tian–Calvet calorimetry in the temperature interval (250–300) K. The vapor pressures for N-methylformamide and N,N-dimethylformamide were measured using static method in the temperature range 238 K to 308 K. The ideal-gas thermodynamic properties were calculated using a combination of the density functional theory (DFT) and statistical thermodynamics. A consistent thermodynamic description was developed using the method of simultaneous correlation, where the experimental and selected literature data for vapor pressures, vaporization enthalpies, and liquid phase heat capacities and the calculated ideal-gas heat capacities were treated together to ensure overall thermodynamic consistency of the results. The resulting vapor pressure equation is valid from the triple point to the normal boiling point temperature. [ABSTRACT FROM AUTHOR]

The growing demand for substitutes of lithium chemistries in battery leads to a surge in budding novel anion‐based electrochemical energy storage, where the chloride ion batteries (CIBs) take over the role. The application of CIBs is limited by the dissolution and side reaction of chloride‐based electrode materials in a liquid electrolyte. On the flipside, its solid‐state electrolytes are scarcely reported due to the challenge in realizing fast Cl− conductivity. The present study reports [Al(DMSO)6]Cl3, a solid‐state metal–organic material, allows chloride ion transfer. The strong Al‐Cl bonds in AlCl3 are broken down after coordinating of Al3+ by ligand DMSO, and Cl− in the resulting compound is weakly bound to complexions [Al(DMSO)6]3+, which may facilitate Cl− migration. By partial replacement of Cl− with PF6−, the room‐temperature ionic conductivity of as‐prepared electrolyte is increased by one order of magnitude from 2.172 × 10−5 S cm−1 to 2.012 × 10−4 S cm−1. When they are assembled with Ag (anode)/Ag–AgCl (cathode) electrode system, reversible electrochemical redox reactions occur on both sides, demonstrating its potential for solid‐state chloride ion batteries. The strategy by weakening the bonding interaction using organic ligands between Cl− and central metallic ions may provide new ideas for developing solid chloride‐ion conductors. [ABSTRACT FROM AUTHOR]

MAX phases represent a crucial building block for the synthesis of MXenes, which constitute an intriguing class of materials with significant application potential. This study investigates the catalytic properties of the Mo 2 TiAlC 2 MAX phase and the corresponding Mo 2 TiC 2 T x MXene for the hydrogen evolution reaction (HER). Characterization by X-ray diffraction (XRD), scanning electron microscopy (SEM), energy-dispersive spectroscopy (EDS), and X-ray photoelectron spectroscopy (XPS) revealed that despite the presence of secondary phases, the HER catalytic activity is primarily influenced by the MAX phase and its derived MXene. Interestingly, the catalytic activity of the MXene improves over time, attributed to the formation of MoO 2 as identified by XPS. This work enhances the understanding of MXene-based materials for electrochemical applications, highlighting crucial structural and chemical transformations that optimize their performance in energy conversion technologies., Competing Interests: The authors declare no competing financial interest., (© 2024 The Authors. Published by American Chemical Society.)