Metal Hydride-Embedded Titania Coating to Coordinate Electron Transfer and Enzyme Protection in Photo-enzymatic Catalysis

Albeit that photo-enzymatic catalysis has sparked more and more attention, its efficiency is restricted by lower electron transfer and poor compatibility between the natural enzyme and synthetic photocatalyst. Herein, a metal hydride-embedded titania (MH/TiO2) coating is engineered on graphitic carbon nitride (GCN) to coordinate electron transfer and enzyme protection for photo-enzymatic alcohol production. The MH/TiO2 coating plays two vital roles: (1) protecting alcohol dehydrogenase (ADH) from deactivation by the GCN core and MH in the coating and (2) permitting electron transfer from GCN to nicotinamide adenine dinucleotide (NAD(+)) and then to formaldehyde catalyzed by ADH. The coordinated photo-enzymatic system could produce methanol at a rate of 1.78 +/- 0.21 mu mol min(-1) mg(ADH)(-1), which is 420% higher than that of the system composed of ADH and GCN without the coating. Moreover, the coordinated system could continuously produce methanol for at least three light-dark cycles, while the system composed of GCN and ADH is completely deactivated after one light-dark cycle. Our study unveils the potential of redox-active mineral coating in coordinating synthetic and biological modules for solar chemical conversion.

Automated summary

The metal hydride-embedded titania coating plays a crucial role in protecting enzymes and facilitating electron transfer, leading to a significantly higher methanol production rate compared to systems without the coating. This coordinated photo-enzymatic system demonstrates potential for efficient solar chemical conversion.