Significant stability enhancement in photocatalytic CO2 reduction via flow-driven strategies

Abstract

Abstract Achieving long-term stability remains a major challenge in photocatalytic CO 2 reduction. Unlike natural photosynthesis, most artificial systems exhibit severe activity losses within hours due to catalyst deactivation and surface degradation. This study investigates the effect of continuous CO 2 and H 2 O flow during the photocatalytic process. Under optimized flow conditions, widely used photocatalysts such as TiO 2 , ZnO, CdS, and C 3 N 4 show up to 50-fold improvement in operational stability, with TiO 2 retaining 80% of its initial activity over 15 days. CO 2 flow plays a more dominant role than H 2 O flow, mitigating product accumulation and preventing catalyst deactivation. Surface and structural analyses reveal that systems without flows suffer from product and intermediate accumulation, while flow-enabled systems maintain clean catalytic surfaces. X-ray absorption spectroscopy confirms the suppression of structural degradation under flow. Here, we establish flow control as a design principle for durable photocatalytic CO 2 reduction, providing a pathway for scalable solar-to-chemical energy conversion.