Carbon-based electromagnetic wave absorbing materials (absorbers) adhered with metallic sulfide nanoparticles of good electrical conductivity attract increasing researchers’ attention. In this study, on the basis of carbon fiber (C_f)@Fe₃O₄ nanocomposites obtained by the electrostatic spinning and reflow method, C_f@FeS₂ nanocomposite was successfully prepared during a further hydrothermal process. The products exhibit excellent electromagnetic wave absorption performances with a minimum reflection loss (RL_min) of −54.11 dB at 2.13 mm matching thickness. At the same time, the optimal effective absorption bandwidth (EAB) value of 6.04 GHz at a thickness of 1.98 mm covers the whole Ku band, suggesting its excellent electromagnetic wave absorption performances. In addition, the interlaced network structure constructed by carbon fiber, outstanding conductivity of FeS₂ nanoparticles, and interfacial polarization from hetero-structure play significant parts in enhancing the electromagnetic parameters and absorption performances. All these results suggest that the C_f@FeS₂ nanocomposites can be taken as a new electromagnetic wave-absorbing material under their low density, simple craft, and strong absorption characteristics.

In the last decade, electromagnetic pollution has caused people’s considerable attention. Developing absorbing material with low cost, lightweight, simple preparation, and high electromagnetic attenuation efficiency has become a feasible means to deal with this problem. In this work, core–shell SiC_NWs@MnO₂@PPy (NWs: nanowires, PPy: polypyrrole) heterostructures composed of SiC nanowires core, MnO₂ nanosheets inter-layer, and PPy coating were successfully prepared through chemical vapor deposition and two-step electrodeposition process. Taking advantage of the interfacial polarization and dipole polarization, the obtained product displays excellent electromagnetic wave absorption performances with the minimum reflection loss (RL_min) of −50.59 dB when the matching thickness is 2.41 mm, and the optimal effective absorption bandwidth (EAB) value reaches to 6.64 GHz at a matching thickness of 2.46 mm, revealing that the SiC_NWs@MnO₂@PPy nanocomposite could be served as a promising electromagnetic wave absorbing material. On the basis of systematic analysis concerning the electromagnetic parameters, the dissipation process of the incident electromagnetic wave was demonstrated reasonably, which may provide a referable preparation strategy for novel heterostructures, especially nonmagnetic lightweight absorbing material.

Development of a general regulatory strategy for efficient overall water splitting remains a challenging task. Herein, a simple, cost-fairness, and general fluorination strategy is developed to realize surface reconstruction, heteroatom doping, and vacancies engineering over cobalt phosphide (CoP) for acquiring high-performance bifunctional electrocatalysts. Specifically, the surface of CoP nanoarrays (NAs) becomes rougher, meanwhile F doped into CoP lattice and creating amounts of P vacancies by fluorination, which caused the increase of active sites and regulation of charge distribution, resulting the excellent electrocatalyst performance of F-CoP NAs/copper foam (CF). The optimized F-CoP NAs/CF delivers a lower overpotential of only 35 mV at 10 mA·cm⁻² for hydrogen evolution reaction (HER) and 231 mV at 50 mA·cm⁻² for oxygen evolution reaction (OER), and the corresponding overall water splitting requires only 1.48 V cell voltage at 10 mA·cm⁻², which are superior to the most state-of-the-art reported electrocatalysts. This work provides an innovative and feasible strategy to construct efficient electrocatalysts.

Cobalt phosphide (CoP) is considered to be a potential candidate in the field of electrocatalysis due to its low-cost, abundant resources and high electrochemical stability. However, there is a great space for further improvement of its electrocatalytic performance since its charge transfer rate and catalytic activity have not reached a satisfactory level. Herein, we design and fabricate a three dimensional urchins like V-doped CoP with different amounts of V-doping on nickel foam electrode. The V-doped CoP/NF electrode with optimized amounts of V-doping (10%) exhibits outstanding hydrogen evolution reaction (HER) performance under universal-pH conditions and preeminent oxygen evolution reaction (OER) performance in alkaline media. Notably, the assembled water-splitting cell displays a cell voltage of only 1.53 V at 10 mA·cm^-2 and has excellent durability, much better than many reported related bifunctional catalysts. The experiment results and theoretical analysis revealed that vanadium atoms replace cobalt atoms in CoP lattice. Vanadium doping can not only raise the density of electronic states near the Fermi level enhancing the conductivity of the catalyst, but can also optimize the free energy of hydrogen and oxygen-containing intermediates adsorption over CoP, thus promoting its catalytic activity. Moreover, the unique nanostructure of the catalyst provides the various shortened channels for charge transfer and reactant/electrolyte diffusion, which accelerates the electrocatalytic process. Also, the in situ growth strategy can improve the conductivity and stability of the catalyst.