Carbon-Coated Nanopowder as Sintering Aid for Water-Atomized Iron Powder

The influence of carbon coating on the nanopowder when used as a sintering aid for water-atomized iron powder is explored. Iron nanopowder without such a coating was used as a reference sintering aid to isolate and depict the influence of the carbon coating. Both nanopowder variants were characterized using XPS and HRTEM, and the results showed a core-shell structure for both nanopowder variants. Iron nanopowder is covered by a 3-4 nm thick iron oxide layer, while the carbon-coated nanopowder is encapsulated with a number of nanometric carbon layers. Thermogravimetry carried out in a pure hydrogen environment shows a multipeak behaviour for carbon-coated nanopowder, while a single peak behaviour is observed for the iron nanopowder. This difference was correlated with chemical analysis. Two types of micro/nanobimodal powders were obtained by mixing the nanopowder with water-atomized iron powder. An improved linear shrinkage was observed when carbon-coated iron nanopowder was added. This can be explained by the reduced surface diffusion in the nanopowder due to the carbon coating, which allows the nanopowder to sinter at higher temperatures and improves densification.

Recent Research Trends for Improving the Stability of Organo/Inorgano Halide Perovskites

Because of their superior optical, and electrical properties, lead halide perovskites have emerged as potential materials for light-emitting-diodes. However, some obstacles have yet to be overcome for practical applications including low exciton binding energy, the difficulty of fabricating uniform perovskite films,, and their instability to heat, light, and moisture. In this review, we focus on strategies to improve the lifetime, and stability of perovskites such as core-shell structure, ligand exchange, and doping.

Heterogenisation of a Carbonylation Catalyst on Dispersible Microporous Polymer Nanoparticles

The methanol carbonylation catalyst, cis-[Rh(CO)2I2]–, has been heterogenised within a dispersible microporous polymer support bearing cationic functionality. The microporous polymer has a core-shell structure in which the porous and insoluble...