Capture and Photocatalytic Conversion of Low‐Concentration CO2 Using a Self‐Assembled CdSe @Carbonic Anhydrase Biohybrid System

Currently, there are large demands for efficient carbon capture and utilization technologies, particularly for low‐concentration CO 2 . While photocatalytic conversion remains a promising sustainable way, its efficiency is often limited by low CO 2 solubility and competitions of side reactions under diluted CO 2 conditions. To improve this situation, a self‐assembled biohybrid system consisting of CdSe quantum dots (QDs) and carbonic anhydrase (CdSe@CA) is designed and synthesized. The biohybrid achieves a CO 2 conversion rate of 47.3 μmol g −1 h −1 in a 100% CO 2 atmosphere with 100% selectivity for CO production. Remarkably, under a 50 vol% CO 2 condition, the CdSe@CA maintains a similar reduction rate, while the performance of CdSe QDs alone drastically drops to 7.6 μmol g −1 h −1 . Even under simulated flue gas condition (15 vol% CO 2 ), the biohybrid can still capture and convert CO 2 at a rate of 8.2 μmol g −1 h −1 . Mechanistic analysis reveals that the synergistic effects between CA's ability to rapidly accumulate the reaction substrate, CO 2 (aq), and rich amide groups to stabilize the reaction intermediate Cd‐CO 2 * together contribute to the biohybrid's excellent low‐concentration CO 2 conversion efficiency. This study presents a promising strategy for capturing and utilizing low‐concentration CO 2 .