A Semi‐artificial Photoelectrochemical Tandem Leaf with a CO₂‐to‐Formate Efficiency Approaching 1 %

Abstract

Semi‐artificial photoelectrochemistry can combine state‐of‐the‐art photovoltaic light‐absorbers with enzymes evolved for selective fuel‐forming reactions such as CO2 reduction, but the overall performance of such hybrid systems has been limited to date. Here, the electrolyte constituents were first tuned to establish an optimal local environment for a W‐formate dehydrogenase to perform electrocatalysis. The CO2 reductase was then interfaced with a triple cation lead mixed‐halide perovskite through a hierarchically structured porous TiO2 scaffold to produce an integrated photocathode achieving a photocurrent density of −5 mA cm−2 at 0.4 V vs. the reversible hydrogen electrode during simulated solar light irradiation. Finally, the combination with a water‐oxidizing BiVO4 photoanode produced a bias‐free integrated biophotoelectrochemical tandem device (semi‐artificial leaf) with a solar CO2‐to‐formate energy conversion efficiency of 0.8 %.

The role of semi-artificial photosynthetic systems in energy and environmental solutions: a critical review

“…However, specialized carbon-fixing bacteria have emerged as valuable assets in effectively utilizing CO2 under mild reaction conditions, offering high selectivity and diversity. Integrating synthetic materials has significantly improved the energy conversion efficiency of biocatalysts (Edwardes Moore et al, 2021;Liu et al, 2023a). As a result, SAPS have made notable strides in converting CO2 into a wide range of organic compounds.…”