In-situ catalytic preparation and characterization of SiC nanofiber coated graphite flake with improved water-wettability

摘要

SiC nanofiber coated graphite flake was fabricated at a relatively low temperature via a novel in-situ catalytic reaction route using Fe(NO3)(3).9H(2)O as a catalyst precursor. The effects of catalyst content, firing temperature, and graphite/Si ratio on the formation of SiC nanofiber and water wettability of modified graphite were investigated. The in-situ formed Fe catalyst facilitated the formation of SiC nanofiber, and its optimal content was found to be 0.6-0.8 wt%. Single-crystalline SiC nanofibers with diameter < 100 nm were resulted from preferential growth along the [111] direction. According to the density functional theory (DFT) calculations, the catalytic effect of in-situ Fe catalyst could be attributed to the increased bond length and weakened bond strength in CO (g) and SiO (g) molecules upon their adsorption onto the Fe catalyst. The water contact angle of SiC nanofiber-coated graphite could be reduced to as low as 6 within just 2.3 s contact time, indicating its substantially improved water wettability.