Electrospinning of ultrafine metal oxide/carbon and metal carbide/carbon nanocomposite fibers

Electrospinning has emerged as a facile technology for the synthesis of ultrafine fibers and even nanofibers of various materials. While carbon nanofibers have been extensively investigated, there have also been studies reported on metal oxide and metal carbide fibers. Yet, comparative studies, especially following the same general synthesis approach, are lacking. In our comprehensive study, we use a sol gel process by which a carrier polymer (cellulose acetate or polyvinylpyrrolidone) is mixed with titanium butoxide, zirconium(IV) acetylacetonate, or niobium n-butoxide to yield nanotextured titania/carbon, zirconia/ carbon, or niobia/carbon nonwoven textiles. Carbothermal reduction between 1300 C and 1700 C effectively transforms the metal oxide/carbon fibers to metal carbide/carbon nanocomposite while preserving the fiber integrity. As a beneficial effect, the fiber diameter decreases compared to the asspun state and we obtained ultrafine fibers: 294 108 nm for ZrC/C, 122 28 nm for TiC/C, and 65 36 nm for NbC/C. The highly disordered and porous nature of the carbon matrix engulfing the metal carbide nanocrystals enables a high specific surface area of up to 450 m g 1 (TiC/C) after carbothermal reduction.