New types composite copper (Cu) and activated carbon (C) for electromagnetic wave absorber materials

Enhanced Visible-Light Absorption of Fe2O3 Covered by Activated Carbon for Multifunctional Purposes: Tuning the Structural, Electronic, Optical, and Magnetic Properties

“…The local bonding between a C atom and another C atom is dominantly covalent and metallic, and has an ionic character in a few clusters of crystal structures . For 15% AC, the shift to the lower 2θ, probably due to the crystal structure’s local strain and bond asymmetry from the C atoms, was not in the stable position in the lattice structure. ,, …”

“…About 40% of the dyes used globally contain organic synthetic bound chlorine, which affects the environment by reducing oxygen concentration and preventing light at the water surface, consequently damaging the aquatic ecosystem. , This in turn cause diseases in humans, who are exposed to the organic synthetic bound chlorine through the water and contaminated food. The chlorine’s effects can vary from cough and chest pain to water retention in the lungs, , and irritation in the skin, eyes, and the respiratory system. − The increasing demand for electronic devices has consequently increased their production, which has directly led to increase in electromagnetic interference (EMI) waves. − EMI has been identified as a new type of pollution that interferes with electronic communications devices and causes threats to human health. − ,− Humans can absorb the pollution and radiation from the electromagnetic (EM) waves; therefore, scientists globally are looking for a way to efficiently shield and absorb these EM waves. There are two main problems with increase in the population globally, which have side effects on human health, they are the availability of clean water and energy.…”

“…The innovations in multifunctional materials have led to photodegradation of wastewater and EM wave absorption by tuning the electronic (band gap), magnetic, and optical properties to increase the absorption from UV light to visible light. − ,− A semiconductor material has unique properties that make it easy to tune these properties, so it is suitable for electromagnetic wave absorption and photocatalyst applications. − Among the semiconductor materials, one of the binary semiconductors is Fe 2 O 3 , with a band gap of about 2 eV, natural abundance, electrochemical stability, and low toxicity. , The limitations of this material are its poor electrical conductivity and optical properties for absorbing the solar spectrum only for wavelengths >600 nm. By doping with high-band-gap materials, the optical absorption is enhanced in the visible regions .…”

“…By doping with high-band-gap materials, the optical absorption is enhanced in the visible regions . Activated carbon (AC) increases the band gaps of CuO and Fe 3 O 4 for absorbing EM wave interference. ,, AC is used to tune the structural, magnetic, and optical properties of the semiconductor by doping it with various materials ,,, depending on the application. ,− In our previous study, we successfully used Co/Fe 2 O 3 –AC for EM absorbers, but the physical phenomena between Fe 2 O 3 and AC are still not fully understood. Several questions exist regarding the relations between the optical, magnetic, electronic, and structural properties that support the applications of multifunctional materials.…”