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ZnO/Co/C/reduced graphene oxide (RGO) composites are synthesized through carbonization of ZnCo-MOF-5/GO under an Ar/H2 flow. The abundant active sites (e.g., functional groups and lattice defects), copious heterointerfaces (among Co, ZnO, C, and RGO), and wrinkled architecture trigger multiple dipole polarization, interface polarization, and enhanced conductive loss. By adjusting the content of RGO, the electromagnetic parameters for ZnO/Co/C/RGO composites were effectively regulated. The minimum reflection loss (RLmin) of ZnO/Co/C/RGO-50 composites is −52.72 dB at 1.70 mm, and the EAB is 3.57 GHz. Futhermore, CST simulation results further confirm the remarkable RCS reduction capacity for ZnO/Co/C/RGO-50 composites. The reduction value of RCS is 22.84 dB m2, and effective absorption can reach the entire angle range. The superior microwave absorption property for ZnO/Co/C/RGO composites is benefited from cooperative action of dielectric loss (dipole polarization, interface polarization, conductive loss) and magnetic loss (natural resonance and exchange resonance). [ABSTRACT FROM AUTHOR]

Herein, an efficient one-dimensional (1D) N-doped Co/C nanotube absorber was designed by a cobalt source and solvent ratio comodulation strategy. First, we explored the influences of different cobalt sources (CoCl2, Co-(OAc)2, Co-(NO3)2, and CoSO4) on the morphology and microwave absorption (MA) property, which showed that CoCl2 facilitated the formation of nanotubes with a relatively uniform diameter and length. Notably, the Co/C nanotubes displayed an ultrawide effective absorption bandwidth (EAB) of 6.885 GHz at 2.2 mm when the filling ratio was only 8 wt %. Then, by adjusting the solvent ratio of isopropanol (IPA) and water, Co/C showed a strong absorption of −44.51 dB with an EAB of 5.44 GHz at 2.35 mm. The outstanding MA performance is ascribed to the synergistic effect of dielectric and magnetic components, which is conducive to optimizing the impedance matching, thus broadening the EAB. In addition, the 1D nanostructure is good for constructing three-dimensional (3D) conductive networks and enhancing conductive loss. Since Co nanoparticles are wrapped in carbon nanotubes (CNTs), the confinement effect can effectively prevent the agglomeration of ferromagnetic nanoparticles, adjusting the MA performance. It is worth mentioning that the maximum Radar cross section (RCS) value of Co/C can be reduced by 28.8 dB m2. Furthermore, the RCS values are all lower than −10 dB m2 from −90 to 90° and the minimum RCS value can reach −46.8 dB m2. This work provides a strategy for designing lightweight MA absorbers with strong RL and ultrawide EAB. [ABSTRACT FROM AUTHOR]

Quaternary nanostructured Cu(In1 − xGax)Se2 (CIGS) arrays were successfully fabricated via a novel and simple solution-based protocol on the electroless deposition method, using a flexible, highly ordered anodic aluminium oxide (AAO) substrate. This method does not require electric power, complicated sensitization processes, or complexing agents, but provides nearly 100% pore fill factor to AAO templates. The field emission scanning electron microscopy (FE-SEM) images show that we obtained uniformly three-dimensional nanostructured CIGS arrays, and we can tailor the diameter and wall thicknesses of the nanostructure by adjusting the pore diameter of the AAO and metal Mo layer. Their chemical composition was determined by energy-dispersive spectroscopy analysis, which is very close to the stoichiometric value. The Raman spectroscopy, x-ray diffraction (XRD) pattern, and transmission electron microscopy (TEM) further confirm the formation of nanostructured CIGS with prominent chalcopyrite structure. The nanostructured CIGS arrays can support the design of low-cost, highlight-trapping, and enhanced carrier collection nanostructured solar cells. [ABSTRACT FROM AUTHOR]