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To cope with sophisticated application scenarios, carbon materials can provide opportunities for integrating multi-functionalities into superior electromagnetic interference (EMI) shielding properties. Nevertheless, carbon materials usually possess high electrical conductivity, which allows them to counteract electromagnetic waves by reflection. Moreover, the identification of factors that dominate the shielding mechanisms has typically been result-oriented, leading to a reliance on a trial-and-error approach for the development of shielding materials. Thus, it is crucial to identify the dominant factors for EMI shielding and elucidate the mechanism underlying the coordination of the balance between reflection and absorption in carbon materials. In this study, we developed a promising and viable approach to create Co@CNTs embedded in carbonized wood (CW) viachemical vapor deposition, producing Co@CNTs/CW foams. The CNTs, densely grown on the CW surface, tightly encapsulated the Co nanoparticles within them. By manipulating the Co content, the defect density and CNT length varied within the Co@CNTs. Through first-principles calculations, these variations substantially influenced the work function, charge density, and dipole moment of the Co@CNTs. Thus, defect-induced and interfacial polarizations were improved, inducing a transformation of the shielding mechanism from reflection to absorption. Regarding the Co@CNTs/CW foams, while high conductivity was essential for achieving satisfactory shielding performance, the enhanced polarization loss dominated the contribution of absorption to the overall shielding effectiveness. Taking advantage of the enhanced polarizations, the Co@CNTs/CW foams exhibited an impressive shielding effectiveness of 42.0 dB, along with an absorptivity of 0.64, which were instrumental in effectively minimizing secondary reflections. Remarkably, these as-prepared foams possessed outstanding hydrophobicity and Joule heating features with a water contact angle of 138° and a saturation temperature of 85.5 °C (2.5 V). Through the stimulation of voltage-driven Joule heating, the absorptivity of Co@CNTs/CW foams can be significantly enhanced to a range of 0.61 to 0.73, irrespective of the Co content. This research would provide a new avenue for designing carbon materials with an absorption-dominated mechanism integrated into EMI shielding performance.

Featherlike PbTe dendrites were synthesized via a simple potentiostatic electrochemical deposition method at room temperature, employing Pb(NO3)2and Na2TeO3as the precursors and tartaric acid as capping molecule. PbTe dendrites were deposited at the potential of −0.2 V for 5 min. This experiment was against the previous report (Chem. Mater.2008, 20, 3306–3314), which considered that the potential oscillation led to the formation of PbTe dendrites. The phase and morphology of the as-prepared product were characterized by means of powder X-ray diffraction (XRD), energy dispersive spectrometry (EDS), (high resolution) transmission electron microscopy (HR/TEM), and scanning electron microscopy (SEM). Some factors influencing the formation of featherlike PbTe dendrites were systematically investigated, including the depositing time, potential, complexant, the original amount of tartaric acid, and Pb2+ion sources. A time-dependent shape evolution process showed that the growth of PbTe underwent three stages from near-spherical nanoparticles, to flowerlike structures, finally to featherlike dendrites.