Unassisted visible-light–driven NADH regeneration based on a dual-photoelectrode system

Abstract

NADH regeneration is crucial for biocatalytic processes. One promising example is visible-light–driven NADH regeneration using water as an electron source. Here, we demonstrate for the first time, to the best of our knowledge, visible-light–driven electrochemical NADH regeneration using water as an electron source without the need for an external bias. This is achieved by combining an IrO_x/TaON (or RhO_x/TaON) photoanode, CdS/CuInS₂ photocathode and [Cp*Rh(bpy)(H₂O)]²⁺, as a catalyst for regioselective reduction of NAD⁺. Furthermore, application of this system to the production of L-lactate from pyruvate using lactate dehydrogenase was attempted.