Wireless Monolithic Tandem Leaf for Semi-Artificial Photosynthesis

Abstract Biocatalytic semi-artificial photosynthesis enables selective solar-to-chemical conversion by harnessing photoelectrocatalytic platforms to drive redox biocatalysis. However, the reliance of most photoelectrochemical (PEC)-based devices on transparent conductive oxides (TCOs) or wired configurations introduces resistive losses and architectural complexity, limiting the translation of biosolar conversion beyond laboratory-scale systems. Here, we report a wireless, monolithic semi-artificial leaf device toward scalable and practical solar biosynthesis. The PEC tandem, composed of a poly(ethylene glycol) (PEG)-modified BiVO4 (PEG:BiVO4) photoanode and a tunnel-oxide-passivated-contact (TOPCon) Si photovoltaic (PV), supplies sufficient photovoltage to reduce O2 to H2O2 on an anthraquinone-2-carboxylic acid (AQC)-functionalized carbon-fiber paper (CFP) cathode under solar light, sustaining over 100 h of stable operation. The photogenerated H2O2 reacts with peroxygenases to catalyze the oxyfunctionalization of substituted benzenes, alkanes, and fatty acids with record-high total turnover numbers of 166,100 (unspecific peroxygenase) and 3,700 (cytochrome P450). Furthermore, the scaling of the PEC device allows the direct conversion of natural light into enantiopure alcohols.