Selective tailoring of covalent bonds on graphitized hollow carbon spheres towards controllable porous structure and wideband electromagnetic absorption

Hollow Porous Bowl-like Nitrogen-Doped Cobalt/Carbon Nanocomposites with Enhanced Electromagnetic Wave Absorption

“…With rapid development and growth in science, technology, and economy, there are extensive research efforts focused on eliminating the current limitations of electromagnetic devices such as electromagnetic interference, pollution, and leakage. , Many endeavors have been devoted to developing electromagnetic microwave absorbing materials with the features of ultrathin, strong, and broadband absorption. − Researchers have attempted to adopt a component-morphology strategy and selected suitable components and complementary microstructures to prepare electromagnetic absorbers with highly efficient electromagnetic wave absorption (EMA). − The shape and size of absorbents are crucial factors to their performance in electromagnetic attenuation . Structures and components always play a decisive effect on the electromagnetic parameters and microwave absorption ability of a material. − …”

Engineering defects in 2D g-C3N4 for wideband, efficient electromagnetic absorption at elevated temperature

“…At a suitable temperature, H 2 O 2 decomposes into strong oxidizing free radicals such as Oc, which break C-N bonds and subsequently incorporates various oxygen-containing species to form C]O bonds. 30 Selectively tailoring the formation of covalent bonds leads to the simultaneous formation of nanopores in the CN. We note here that the cleavage of C]N bonds requires higher energy compared with C-N bonds.…”

Cubic-like Co/NC composites derived from ZIF-67 with a dual control strategy of size and graphitization degree for microwave absorption

“…However, as the carbonization temperature continues to increase, the discontinuous graphitization region gradually merges and becomes larger, and the dipole center at the edge of the graphitization region/disorder region decreases, thus reducing the dipole polarization. 48 In addition, the improvement of the crystallinity of Co can enhance the interfacial polarization of Co/C to a certain extent. 49,50 It is the common adjustment of these polarization mechanisms that leads to the change in the dielectric constant and the Cole-Cole semicircle.…”