Huifang Wang

Low-temperature catalytic synthesis of SiC nanopowder from liquid phenolic resin and diatomite

ABSTRACT 3C–SiC nanopowder was catalytically synthesised at 1400°C for 3u2005h in argon using industrial diatomite powder and phenolic resin as raw materials, and cobalt nitrate as a catalyst precursor. Phase composition and microstructure of product samples were characterised using X-ray diffraction analysis, scanning electronic microscopy and transmission electronic microscopy. The effects of temperature, catalyst content and reaction time on the formation of SiC were examined. The results indicated that (1) phase pure 3C–SiC can be synthesised at 1400°C for 3u2005h using 1.0u2005wt-% Co catalyst; (2) if no catalyst was used, only little 3C–SiC was formed under the identical firing condition; (3) as-prepared 3C–SiC nanoparticles had irregular shapes with overall sizes of 30–300u2005nm. Density functional theory calculations further reveal that the Co catalyst assisted Si–O bond breaking and thus the SiC formation.

Lotus-Seedpod-Bioinspired 3D Superhydrophobic Diatomite Porous Ceramics Comodified by Graphene and Carbon Nanobelts

Hydrophobic and oleophilic sorbents play an important role in the remediation processes of oil spills/leakages occurring globally from time to time. In this work, for the first time, lotus-seedpod-bioinspired 3D superhydrophobic diatomite porous ceramics with good mechanical strength and thermal stability were fabricated, using inexpensive porous diatomite as a substrate, and graphene/carbon nanobelts as modifiers. Thanks to the presence of graphene coating and in situ formed carbon nanobelts, the surface energy of the final porous ceramics was reduced and their surface roughness increased, conferring superhydrophobicity on them. As-prepared porous ceramics demonstrated 3-30 times higher adsorption capacity in oil/water separation than their conventional inorganic sorbent materials, and had compressive strength 70-270 times higher than that of a sponge/graphene-based sorbent material. The present work could additionally offer a new strategy for the treatment/recycle of waste plastics, the so-called white pollution.