Silva Caio C G, Martins Guilherme, Luís André, Rojas-Mantilla Hernán D, Rovisco Ana, Martins Rodrigo, Fortunato Elvira, Pereira Inês A C, Zanoni Maria V B, Garrido Saulo S, Conzuelo Felipe
Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa, Av. da República, 2780-157 Oeiras, Portugal.
Instituto de Química, Universidade Estadual Paulista (UNESP), Rua Professor Francisco Degni, 55, Araraquara, 14800-060, São Paulo, Brazil.
ACS Electrochem. 2025 May 21;1(7):1184-1193. doi: 10.1021/acselectrochem.5c00053. eCollection 2025 Jul 3.
Photosynthetic microorganisms are promising candidates for sustainable energy production in photobio-electrochemical systems. However, integrating them with electrodes is challenging due to the compartmentalized nature of photosynthetic organelles. Microalgae, in particular, have a more complex cell structure than cyanobacteria, leading to low electron transfer rates and compromising electrochemical communication. In this study, we propose a hybrid biophotoelectrode that integrates intact microalgae cells with a WO semiconductor electrode using polydopamine for cell entrapment and charge transfer enhancement. The biophotoelectrode delivers photocurrents of up to 24 μA cm under visible light illumination with an incident light power below 6.0 mW cm. The photoelectrode performance and the origin of electron flow are investigated, confirming a substantial contribution of immobilized microalgae to the overall photocurrent. We present a proof-of-concept application of the microalgae-based hybrid electrode in combination with a formate dehydrogenase biocathode for the implementation of a biophoto-electrochemical cell for the conversion of CO to formate assisted by light. The system demonstrates the potential for coupling photosynthetic processes with bioelectrochemical conversion, achieving efficient and sustainable production of value-added chemicals. These findings advance our understanding of photosynthetic cell-electrode interactions in hybrid systems, offering insights for developing photobio-electrochemical devices and innovative conversion strategies for waste products.
光合微生物是光生物电化学系统中可持续能源生产的有前途的候选者。然而，由于光合细胞器的区室化性质，将它们与电极整合具有挑战性。特别是微藻，其细胞结构比蓝细菌更复杂，导致电子转移速率低，并损害电化学通讯。在本研究中，我们提出了一种混合生物光电极，该电极使用聚多巴胺将完整的微藻细胞与WO半导体电极整合，用于细胞捕获和电荷转移增强。该生物光电极在低于6.0 mW cm的入射光功率下，在可见光照射下可提供高达24 μA cm的光电流。研究了光电极性能和电子流动的起源，证实固定化微藻对总光电流有重大贡献。我们展示了基于微藻的混合电极与甲酸脱氢酶生物阴极结合的概念验证应用，用于实现光辅助将CO转化为甲酸的生物光电化学电池。该系统展示了将光合过程与生物电化学转化耦合的潜力，实现了高效和可持续的增值化学品生产。这些发现推进了我们对混合系统中光合细胞-电极相互作用的理解，为开发光生物电化学装置和废物创新转化策略提供了见解。
