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The purity and uniformity issues with tunable structures are significant challenges for the fabrication of porous fibers. In the present work, we reported the fabrication of mesoporous SiC fibers via electrospinning of polyureasilazane and polyvinylpyrrolidone combined with subsequent high-temperature pyrolysis treatment. The resultant mesoporous fibers were systematically characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), and high-resolution transmission electron microscopy (HRTEM). The contents of polyureasilazane within the solutions played a critically important role in the formation of mesoporous SiC fibers, enabling the well-controlled growth of the mesoporous SiC fibers. As compared to the reported works, the as-fabricated mesoporous fibers exhibit very uniform microstructures, very high purities, and highly defined fiber shapes with well-controlled structures, which could inspire and activate their potential applications in photocatalysts and catalyst supports.

We report for the first time the synthesis of Al-doped 6H-SiC nanowires with high yield and high quality. The nanowires were obtained by the catalyst-assisted pyrolysis of polymeric precursors with FeCl2 as the catalyst. The doping concentrations were controlled by tailoring the Al concentrations in the precursors. It was observed that the Al dopants caused red-shifts of the photoluminescence bands. The results suggest a simple technique to synthesize Al-doped SiC nanomaterials in a controlled manner. The obtained nanowires could be useful for making optical and electronic nanodevices.

In this paper, we have demonstrated the Oswald ripening growth of single-crystalline Si3N4 nanoplates. The formation of the plates involves three basic steps: formation and aggregation of the nanoparticles, grain coalescence within selective areas, and growth of one coarsened grain at the expense of the rest of the nanoparticles via an Oswald ripening process assisted by the oriented attachment mechanism. The obtained nanoplates exhibit an extremely high aspect ratio with an ultrathin thickness, flat surface, and perfect crystal structure, and they could be utilized as substrates for constructing nanodevices.

We have demonstrated the growth of asymmetric ordered Si3N4 nanodendrites via the catalyst-assisted pyrolysis of a polymeric precursor. The growth of the unique structure is due to the usage of a co-catalyst composed of a Fe-Al mixture. First, Si3N4 stems grow at an early stage via a gas−solid process with Al being the catalyst. Fe is then selectively deposited on the negatively charged (010) surface of the Si3N4 stem to form catalytic droplets which promote the growth of the ordered nanowire branches. The novel nanostructures could be useful for the fabrication of nanodevices and nanocomposites. The principle demonstrated here is applicable for synthesizing ordered branched nanodendrites in other material systems.