Light‐Carbon Double Transfer Membrane for Carbon Fixation in Microalgae

ABSTRACT The carbon fixation technology based on microalgae has garnered significant attention due to its efficient photosynthesis and resource utilization. However, as algal density increases, light attenuation and insufficient CO ₂ supply become major bottlenecks. This study proposes a light‐carbon double transfer membrane (LCTM) that simultaneously facilitates light and CO ₂ transmission. By employing refractive index matching, the membrane improves transmittance by reducing light scattering and enhances CO ₂ enrichment and permeation efficiency through the incorporation of CO ₂ ‐affinity materials. The LCTM, fabricated using non‐solvent‐induced phase separation combined with coating techniques, achieves a transmittance of 89% and a CO ₂ permeation rate of 1867 GPU, while exhibiting excellent flexibility. When applied in photobioreactors, it enables efficient simultaneous transfer of light and CO ₂ , increasing microalgal biomass by 80.8% to 3.20 g/L. Under 12% CO ₂ aeration conditions, CO ₂ fixation rates surpassed those achieved with air aeration by 50%, reaching 0.68 g/L/d. A 120‐day continuous test demonstrated the stability and reproducibility of LCTM. This study not only offers an innovative solution to the challenges of light attenuation and CO ₂ supply limitations in microalgal carbon fixation but also establishes a foundation for sustainable carbon sequestration technology.