Nanocomposites with a well-defined sandwich-like nanostructure were prepared via in situ growing NiCo-layered double hydroxide nanosheets with tunable Ni/Co ratios on reduced graphene oxide (rGO). Electrochemical impedance spectra and N₂ adsorption/desorption isotherms confirmed that these sandwich nanostructures effectively promoted charge transport and enlarged the specific surface area. The nanocomposites with Ni : Co = 2 : 1 exhibited a maximum specific capacitance of 2130 F g⁻¹ at 2 A g⁻¹, excellent rate capability (72.7% retention at 15 A g⁻¹), and cycling stability. Asymmetric supercapacitors were assembled with these nanocomposite cathodes and rGO as a negative electrode (anode), and demonstrated an energy density of 34.5 W h kg⁻¹ at a power density of 772 W kg⁻¹, while maintaining a capacity retention of 86.7% after 10 000 cycles at 5 A g⁻¹. The robust electrochemical properties indicate the composites as promising electrodes for electrochemical energy storage devices.

Carbon-based materials derived from metal–organic frameworks (MOFs) have drawn increasing research attention for high-performance electromagnetic wave absorption due to their unique microstructure. In this work, MOF-derived ZrO₂/C octahedra have been successfully synthesized from UIO-66. The ZrO₂ nanoparticles (4–6 nm) were evenly distributed inside the octahedral carbon matrix with an average edge length of 500 nm. Benefiting from the suitable carbonization treatment, which leads to a strong attenuation capacity and a harmonious impedance matching characteristic, superb electromagnetic wave absorption performances with a minimum reflection loss (RL) value of −58.7 dB (16.8 GHz, 1.5 mm) have been achieved. And the effective absorption bandwidth (EAB; RL < −10 dB) could cover 91.3% (3.4–18.0 GHz) of the measured frequency within the thickness range of 1.0–5.0 mm. Thus, the MOF-derived ZrO₂/C nanocomposites with light weight, thin thickness, high stability, strong absorption intensity and ultra-wide absorption bandwidth exhibit huge application potential as high-performance electromagnetic wave absorption materials.

The sensing mechanisms and effective strategies for enhancing the formaldehyde detection performance of metal oxide semiconductors have been reviewed.

Flower-like heterogeneous Co/MnO@C composites were facilely synthesized for highly efficient electromagnetic wave absorption. The effect of Co contents on the electromagnetic performance and the absorption mechanism was thoroughly investigated.