Next-generation carbon-negative composites: A paradigm shift in materials science through CO₂–derived carbon fiber synthesis

A critical strategy in mitigating climate change is the conversion of captured CO₂ into durable, high-value materials. This perspective focuses on an emerging carbon capture and utilization pathway: the electrochemical synthesis of high-performance carbon fibers. This technology offers a dual benefit by simultaneously sequestering a greenhouse gas and producing a superior lightweight material. However, as detailed in this work, the net carbon balance is highly dependent on the energy source and system boundaries; carbon-negative operation is only achieved when renewable electricity is used. A quantitative LCA framework is provided. It examines the key technologies involved, from point-source capture and direct air capture methods that supply the CO₂ feedstock, to molten salt electrochemical and tandem catalytic processes that convert gaseous CO₂ into solid carbon nanofibers and carbon nanotubes. This pathway represents a frontier in next-generation materials engineering, where the source molecule dictates a novel microstructure and enables strong sustainability credentials. The perspective details the core reaction mechanisms and analyzes the exceptional mechanical properties of the resulting carbon composites, which may contribute to advancements in lightweighting in the automotive and aerospace industries. Recent advances in CO₂ electroreduction have demonstrated tunable CNT synthesis via fluoride-assisted carbonate conversion at temperatures as low as 500°C, achieving Faradaic efficiencies up to 93.6% with CNT diameters as small as 18.7 nm, suggesting that electrochemical synthesis conditions can be optimized for specific nanomaterial morphologies. It further explores the integration of these materials into advanced manufacturing techniques such as 3D printing and automated fiber placement to improve production efficiency. Crucially, when powered by renewable energy, this approach offers a route to carbon-negative manufacturing by embedding atmospheric carbon into long-lived products. The perspective concludes by assessing current technological readiness, addressing challenges in energy consumption and scalability, and outlining the research and policy frameworks required to advance this technology toward industrial viability. Unlike prior reviews that focus either on capture or on conventional fiber manufacturing, the present work integrates both fields with critical analysis of trade-offs, literature bias, and end-of-life scenarios. This perspective provides the first quantitative cradle-to-grave LCA framework for CO₂-derived carbon fibers, including uncertainty ranges, sensitivity to electricity carbon intensity, and stage-wise contribution analysis, as well as a techno-economic assessment with CAPEX/OPEX estimates and a commercialization roadmap.