C–C-Coupled Two-Dimensional Conjugated Polymer Nanosheets as Highly Efficient Photocatalysts for NADH Regeneration and Biocatalytic Artificial Photosynthesis

Two-dimensional (2D) polymers, due to their abundance of active sites and fast charge separation and transfer efficiency, have been regarded as ideal candidates for high-performance photocatalysts. However, current 2D polymers suffer from drawbacks of harsh preparation conditions, limited thermal/photostability, and poor structural diversity. In this work, the C–C-coupled 2D polymer 2D@COP-DBTS was synthesized via isopropanol-assisted exfoliation of the corresponding layerlike linear polymer. The obtained 2D@COP-DBTS demonstrates a competitive conversion of 60.8% in NADH regeneration. DFT calculations reveals that the photocatalyst has strong affinities to reactive substrates, guaranteeing quick electron transfer and prominent catalytic efficiency. When the in situ NADH regeneration is combined with formate dehydrogenase, an extremely high amount of formate (572.92 mmol, turnover frequency (TOF) of 63500 mmol gcat–1 h–1) is accumulated. In addition, 0.0351 mmol of l-glutamate (TOF of 0.488 mmol gcat–1 h–1) is also obtained in the 2D@COP-DBTS/glutamate dehydrogenase mixture, indicating high feasibility of formate and l-glutamate production in the polymer/enzyme-coupled system.