To further improve the catalytic carbonization efficiency of polymer composites for the formation of compact protective layers in the combustion process, a novel type of Fe-CNTs was prepared in large scale. The Fe-CNTs were used as nanofillers to efficiently improve catalytic carbonization, flame retardancy, and mechanical performances of epoxy resin (EP). With the incorporation of 6 wt% Fe-CNTs, the LOI value of the EP/Fe-CNTs nanocomposites was improved to 35.0 and the UL-94 V-1 rating was passed with an average (t₁ + t₂) value of 13.3. As compared to pure EP, the PHRR, THR, and TSP of EP/6 wt% Fe-CNTs nanocomposites decreased by 30.7%, 39.1%, and 48.6%, respectively. The significantly improved flame retardancy could be attributed to the compact carbonaceous ceramic layers, which significantly retarded the transfer of heat and combustible gas between the EP nanocomposites and the flame zone. Moreover, the EP/Fe-CNTs nanocomposites exhibited excellent impact and tensile strength performances due to the formation of a strong three-dimensional network structure in the EP matrix.

The reasonable design of electrode materials is crucial for tuning the electrochemical performances of advanced energy storage systems. Co–Ni–Se nanosheets uniformly growing on a butterfly-wing-derived carbon framework (Co–Ni–Se/BWCF) with strong anchoring are devised and prepared by a microwave treatment–ion exchange–chemical etching–hydrothermal selenization technique. Benefiting from its multi-components and unique structure, Co–Ni–Se/BWCF-160 exhibits excellent supercapacitor and sodium storage performances as self-supporting electrodes. When Co–Ni–Se/BWCF-160 is used as a supercapacitor electrode, its capacity is as high as 3050 F g⁻¹ at 1.0 A g⁻¹ and maintained 1006 F g⁻¹ at 20.0 A g⁻¹. The asymmetric supercapacitor based on Co–Ni–Se/BWCF-160 and a-BWC achieved a high energy density of 49.7 W h kg⁻¹ at 1052 W kg⁻¹, and the capacity retention reaches 93.3% at 10 A g⁻¹ after 5000 cycles. Evaluated as a sodium ion battery self-supporting anode, the initial discharge specific capacity is up to 703 mA h g⁻¹ at 0.1 A g⁻¹, and retains 403 mA h g⁻¹ after 100 cycles. More importantly, it still achieves 211 mA h g⁻¹ at 1.0 A g⁻¹. The overall outstanding electrochemical performances can be explained in that the Co–Ni–Se nanosheets expose more active sites, and the ordered hole arrays ensure sufficient wetting between the electrolyte and electrode materials. Additionally, this unique structure enables more efficient ion/electron transfer and diffusion between the BWCF and Ni–Co–Se, effectively accelerating the electrochemical reaction kinetics.

Silica aerogels are considered as the distinguished materials of the future due to their extremely low thermal conductivity, low density, and high surface area. They are widely used in construction engineering, aeronautical domains, environmental protection, heat storage, etc. However, their fragile mechanical properties are the bottleneck restricting the engineering application of silica aerogels. This review briefly introduces the synthesis of silica aerogels, including the processes of sol–gel chemistry, aging, and drying. The effects of different silicon sources on the mechanical properties of silica aerogels are summarized. Moreover, the reaction mechanism of the three stages is also described. Then, five types of polymers that are commonly used to enhance the mechanical properties of silica aerogels are listed, and the current research progress is introduced. Finally, the outlook and prospects of the silica aerogels are proposed, and this paper further summarizes the methods of different polymers to enhance silica aerogels.