The treatment of dye polluting water is one of the most important tasks that are concerned with water resources. Herein, a nanofiber composite membrane (NCM) is fabricated with an aim to effectively degrade organic dyes. First, α‐Fe2O3 nanoparticles are loaded on the surface of graphene oxide (GO) sheets through hydrothermal method. Then the as‐prepared α‐Fe2O3@rGO sheets are deposited on polyacrylonitrile (PAN) nanofiber mat via vacuum filtration to obtain α‐Fe2O3@rGO/PAN NCM. Thus, the NCM has a double‐layer structure with α‐Fe2O3@rGO as the upper layer and PAN nanofiber as the lower layer (support layer), providing structural advantages in photocatalytic degradation in solution. The composition, morphology, and structure of the NCM are characterized in detail. Photocatalytic experiments show that the NCM can effectively degrade a variety of organic dyes, among which the degradation rate of methylene blue is as high as 98.5% within 2 h. Moreover, the degradation rate still remains at high level after 5 cycles and the NCM remains intact, indicating the reusability of the NCM. It is in particular worth highlighting that high degradation efficiency is obtained even under natural sunlight, demonstrating great potential applications of the NCM in industrial dye wastewater treatment.

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The hydroxyls on SiC nanosheet provide local protons, stabilize the intermediates and localize the electrons for deep photoreduction of CO2.

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Ceramic fiber has the advantages of low density, high strength, high temperature resistance and good mechanical vibration resistance. It is the critical high temperature thermal insulation materials especially in thermal protection fields such as aerospace vehicles, nuclear power plants and chemo-metallurgical industry, etc. The traditional ceramic fiber with large diameter (> 5 μm), high brittleness and high thermal conductivity has been greatly restricted in high temperature thermal insulation fields. In recent years, more and more attention has been paid to the preparation of micro-nano ceramic fibers by decreasing the diameter of fiber, which is not only beneficial to improve the mechanical properties of the fibers, but also to enhance their high temperature thermal insulation properties. Further, by finely regulating the composition and structure of the micro-nano ceramic fibers that intrinsically affecting the heat transfer (heat conduction of gas, heat conduction of solid and radiative heat transfer) mechanism in micro-nano ceramic fibers, the high temperature thermal insulation performance can be effectively improved, which is the current focus of the micro-nano ceramic fibers in high temperature thermal insulation fields. The thermal insulation 无 机 材 料 学 报 第 36 卷 mechanism of the micro-nano ceramic fibers was firstly introduced. Then, based on the research at home and abroad, this review divides the current micro-nano ceramic fibers into three categories according to the difference of their composition and structure, namely fibers aerogels, hollow/porous fibers and composite fibers. The latest research progress on composition and structure optimization of micro-nano ceramic fibers for high temperature thermal insulation is reviewed, and the future development tendency is prospected.

Exploitation of low‐cost and efficient photocatalysts for selective reduction of CO2 into fuels such as methane or methanol is highly desired in the field of solar‐to‐fuel conversion. Herein, ultrathin SiC nanosheets (NSs) with high crystallinity are prepared using two‐dimensional reduced graphene oxide as sacrificial template. The ultrathin feature of SiC NSs readily shortens the migration distance of photoexcited carriers, thereby reducing the recombination probability and providing more energetic electrons to participate in CO2 reduction. Consequently, both the yield (3.11 μmol h−1 g−1) and selectivity (90.6%) of CH4 over SiC NSs demonstrate dramatic improvements in comparison with that of micro‐size SiC (0.76 μmol h−1 g−1, 77.9%) and commercial TiO2 (1.46 μmol h−1 g−1, 61.0%). The initial absorption and activation of CO2 molecules on the surface of SiC NSs is confirmed by the in situ diffuse reflectance infrared Fourier transform spectroscopy. The SiC NSs can promote the deep reduction of carbon intermediate into CH4 thanks to the strong reduction potential of photoexcited electrons. This work not only proves ultrathin SiC NSs to be a promising photocatalyst for CO2 reduction, but also provides novel insights into deep photoreduction of CO2 to CH4.

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