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Metal-organic framework (MOF) derivatives have attracted tremendous attention in electromagnetic (EM) wave absorption owing to their unique properties such as structural diversity, tailorable components and light weight. However, they fail to demonstrate decent EM attenuation performance due to inadequate heterostructures and multiple reflections. Here, 3D carbon skeleton (CS)/MOF derivatives are prepared via an in situ growth and pyrolysis strategy which is based on chitosan derived CS and the MOFs ZIF-8 and ZIF-67. As a result, CS/ZIF-8 600 °C demonstrates excellent EM absorption, whose minimum reflection loss is -41.85 dB with an effective absorption bandwidth of 2.56 GHz. In addition, the CS/MOF composites exhibit splendid corrosion resistance in complex environments such as neutral, acidic and alkaline.

To address the intrinsic limitations of both TiO 2 and MXenes, we propose an effective strategy for the engineering of a 3D Ti 3 C 2 /TiO 2 nanorod hybrid, where the in situ synthesized TiO 2 nanorods are homogeneously decorated onto the surface of 3D Ti 3 C 2 MXene via simple oxidation. As the LIB anode, it demonstrates exceptional long-term cycling stability with a specific capacity of 384.1 mA h g -1 after 600 cycles at 1.0 A g -1 .

A vertically-stacked MXene/rGO composite membrane with ultrashort transport channels is reported here, which demonstrated outstanding molecular sieving, i.e. , H 2 /CO 2 selectivity of up to 83 together with high H 2 permeance of 2.7 × 10 -7 mol m -2 s -1 Pa -1 at 120 °C, highlighting its applicability for H 2 /CO 2 separation in CO 2 capture and sequestration.

The employment of electromagnetic (EM) absorbers integrating elaborate architecture, enhanced microwave absorption and multifunctional features remains a formidable challenge in practical applications including military stealth and incoming 5G electronic information era. Herein, a novel microwave absorber has been fabricated by in-situ growing carbon nanotubes (CNTs) on the prismatic nickel-cobalt (NiCo) clusters derived from Ni-Co layered double hydroxides (NiCo-LDH) via catalytic carbonization of ethyl acetate. The NiCo/CNTs composites with highly porous texture could provide sufficient open space to balance the impedance and introduce magnetic loss mechanism. Accordingly, the absorbers achieved remarkable EM absorption performance with a minimum reflection loss of -46.2 dB at 1.5 mm and broad bandwidth of 5.8 GHz owing to synergistic magnetic-dielectric effects and distinct structural merits. The NiCo/CNTs absorber manifests superior radar wave attenuation by the radar cross section simulation and density functional theory (DFT) was also performed to elucidate the potential mechanisms of the heterostructure formation and performance enhancement in the NiCo/CNTs composites. This work is expected to provide new insights or inspirations to modulate EM properties by rationally designing heterostructure for the elimination of severe EM pollution., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2022 Elsevier Inc. All rights reserved.)

Biomass-derived carbon materials have received a surge of scientific attention to develop lightweight and broadband microwave absorbers. Herein, rodlike porous carbon materials derived from cotton have been fabricated with uniformly dispersed CoFe 2 O 4 nanoparticles via facile and scalable process. The combination of magnetic particles and carbonaceous material is advantageous to realize the magnetic-dielectric synergistic effect which could effectively promote the dissipation of incident waves, giving rise to an optimal reflection loss value of -48.2 dB over a qualified bandwidth (4.8 GHz) at 2.5 mm. The cotton-derived carbon rods with conductive network not only act as a supporter to carry the CoFe 2 O 4 nanoparticles, but also provide massive heterointerfaces to facilitate the interfacial polarization. In consideration of the renewable and abundant resource of cotton, the as-prepared CoFe 2 O 4 /C composites would meet the increasing demand of lightweight and highly efficient microwave absorbers., (© 2022 IOP Publishing Ltd.)

Heterogeneous electrocatalytic reactions only occur at the interface between the electrocatalyst and reactant. Therefore, the active sites are only necessary to be distributed on the surface of the electrocatalyst. Based on this motivation, here, we demonstrate a systematic study on surface tuning for a carbon-based electrocatalyst from metal-free (with the heteroatoms N and S, NS/C) to metal-containing surfaces (with Co, N, and S, CoNS/C). The CoNS/C electrocatalyst was obtained by pyrolyzing the Co precoordinated and p -toluenesulfonate-doped polypyrrole (PPy). It was found that the coordination of Co on the PPy ring tuned the final carbon electrocatalyst into a catalyst with a CoN x moiety-rich surface. In addition, the as-synthesized CoNS/C was determined to have a very high loading of cobalt up to 2.02 wt %. The pyrolysis of the cobalt-containing precursor tends to proceed toward a characteristic of a higher sp 2 carbon content, a higher surface area, and more nitrogen as well as active nitrogen sites than its metal-free counterpart. The most distinguished feature for such a catalyst is that the truly most active component is only distributed on the surface, in contrast with that of the conventional metal-N-based catalyst present throughout the bulky structure. Especially, the electrocatalytic activity toward oxygen evolution reaction (OER) has been investigated experimentally and theoretically. The results showed that the OER performance of the carbon-based electrocatalyst was remarkably boosted after the introduction of Co with an overpotential decrease from 678 to 345 mV at 10 mA cm -2 . Furthermore, CoNS/C displayed an excellent durability upon a long-term measurement. The apparent activation energy measurements revealed that the metal-rich surface contributed to overcome the energy barrier for OER. In addition, density functional theory calculations have been conducted to explain the correlated OER mechanism. This study is expected to provide an effective strategy for the design and the synthesis of highly active metal-nitrogen-type electrocatalysts with a high metal loading for various electrocatalytic reactions.