Transforming Petroleum asphalt into Carbon Fibers and Related Metal/Oxide Composites by Electrospinning Synthesis

Abstract

Petroleum asphalt, due to its low cost and high carbon content, is a promising precursor for high-value carbon materials. However, electrospinning-based fabrication requires complex pretreatments and a high amounts of additives like polyacrylonitrile (PAN), polyvinyl pyrrolidone (PVP), or polystyrene (PS), which limits asphalt utilization. Furthermore, comparative studies on different types of supported asphalt-based carbon fibers remain limited. Here, N,N-dimethylacetamide (DMA) was employed as a solvent to achieve a mass ratio of asphalt to PAN of 2:1, facilitating the preparation of asphalt-based carbon fibers loaded with various metal salts, including metalloporphyrin salts, nitrates, and metal oxides. Comparative analysis indicated that small amounts of nitrates promoted the formation of well-defined fiber morphologies, whereas oxides interacted with asphalt to create unique bead-on-string structures. Additionally, the presence of oxides delayed the release of gaseous products during carbonization, resulting in carbon fibers with finer diameters. Electrochemical evaluations demonstrated that the bead-on-string structures exhibited notable advantages in oxygen evolution reaction (OER) activity. These findings offer valuable insights for the design of carbon fibers with high asphalt content for advanced applications.