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Aluminum nitride (AlN) has high thermal conductivity, good insulation, low thermal expansion coefficient, non-magnetic, and other excellent properties used as a key material for high-end equipment in semiconductor, electric vacuum, and other fields. Especially in aerospace, rail transportation, new energy equipment, high-power LED, 5G communication, power transmission, industrial control, and other fields of power devices, AlN has an irreplaceable role. The high-grade powders are the basis for the preparation of high-performance ceramics. The properties of AlN powders directly affect the forming, sintering, microstructure, and performance of the AlN ceramics. Carbothermal reduction-nitridation method is a promising method to produce the AlN powders with high purity, fine particle size, and high sintering property. The evaluation indexes of the AlN powders and the research progress on the carbothermal reduction-nitridation of AlN powders were reviewed in this paper, and the direction and trend of future research and industrialization were proposed.

Owing to sluggish reaction kinetics and high potential, oxygen evolution reaction (OER) electrocatalysts face a trade-off between activity and stability. Herein, an innovative topological strategy is presented for preparing 2D multimetallic (oxy)hydroxide, including ternary CoFeZn, quaternary CoFeMnZn, and high-entropy CoFeMnCuZn. The key to the synthesis lies in using Ca-rich brownmillerite oxide as a precursor, which possesses inherent structural flexibility enabling tailored elemental adjustments and topologically transforms from a point-shared structure of metal-oxygen octahedrons into an edge-shared structure under alkaline conditions. The presence of Zn in the catalysts causes a shift in the center of the O2p band toward the Fermi level, resulting in more Co 4+ species, which drive holes into oxygen ligands to promote intramolecular oxygen coupling. The triggered lattice oxidation mechanism is identified by detecting peroxo-like (O 2 2- ) negative species using tetramethylammonium chemical probe, along with 18 O isotope labeling experiments. As a result, the catalyst demonstrates an overpotential of 267 mV at 10 mA cm -2 , ranking it among the top-performing non-Ni-based catalysts. Importantly, the catalysts also show high Fe-leaching resistance during OER compared to conventional NiFe and CoFe hydroxides/(oxy)hydroxides. The assembled zinc-air battery enables stable operation for over 225 h at a low charging voltage of 1.93 V., (© 2024 Wiley‐VCH GmbH.)