Carbon Dots and [FeFe] Hydrogenase Biohybrid Assemblies for Efficient Light-Driven Hydrogen Evolution

Abstract

Artificial photosynthesis is seen as a path to convert and store solar energy into chemical energy for our society. In this work, highly fluorescent aspartic acid-based carbon dots (CDs) are synthesized and employed as a photosensitizer to drive photocatalytic hydrogen evolution with an [FeFe] hydrogenase (CrHydA1). The direct interaction in CDs from l-aspartic acid (AspCDs)/CrHydA1 self-assembly systems, which is visualized from native gel electrophoresis, has been systematically investigated to understand the electron-transfer dynamics and its impact on photocatalytic efficiency. The study discloses the significant influence of the electrostatic surrounding generated by sacrificial electron donors on the intimate interplay within the oppositely charged subunits of the biohybrid assembly as well as the overall photocatalytic performance. The system reaches an external quantum efficiency of 1.7% at 420 nm and an initial activity of 1.73 μmol­(H2) mg–1(hydrogenase) min–1 under favorable electrostatic conditions. Owing to the ability of the synthesized AspCDs to operate efficiently under visible light, in contrast to other materials that require UV illumination, the stability of the biohybrid assembly in the presence of a redox mediator extends beyond 1 week.

Conjugated nanomaterials for solar fuel production

“…Composites are particularly exciting in this respect, and interfaces with biology, such as enzymes offer further potential directions. 82 Beyond this there are many other photocatalytic applications that have not yet been studied with conjugated nanomaterial photocatalysts such as CO 2 reduction, hydrogen peroxide production and nitrogen fixation, and it can be expected that conjugated nanoparticular photocatalysts will be applied to these areas soon too.…”

A Periplasmic Photosensitized Biohybrid System for Solar Hydrogen Production

“…[5][6][7][8] Accordingly, considerable efforts have been made to fabricate the purified hydrogenase biohybrid systems. [9][10][11][12][13][14][15][16] However, the low yield and complicated purification process of hydrogenase severely restrict the wide application of these biohybrid systems.A novel approach using whole cells expressing hydrogenases as the biocatalyst has shown obvious advantages over purified hydrogenases biohybrid system due to the easy fabrication and high stability. To date, two classes of whole-cell biohybrid systems were pursued, in the form of the extracellular photosensitized biohybrid system and the cytoplasmic photosensitized biohybrid system.…”

“…[5][6][7][8] Accordingly, considerable efforts have been made to fabricate the purified hydrogenase biohybrid systems. [9][10][11][12][13][14][15][16] However, the low yield and complicated purification process of hydrogenase severely restrict the wide application of these biohybrid systems.…”

[FeFe] Hydrogenase based Prototype Photosensitizer-Catalyst Dyad for Hydrogen Generation under Visible Light

“…Few exceptions are given by e.g. xanthene dyes, (zinc) porphyrins [1d, 4] or carbon dots [5] as light harvesters. Recently, we reported another fully precious metal-free example, a dibenzosilole photosensitizer directly attached to the catalyst, yield a TON of 539 for HER under UV light (254 nm).…”