A Multi-Heme Flavoenzyme as a Solar Conversion Catalyst

Abstract

The enzyme flavocytochrome <i>c</i>₃ (fcc₃), which catalyzes hydrogenation across a CC double bond (fumarate to succinate), is used to carry out the fuel-forming reaction in an artificial photosynthesis system. When immobilized on dye-sensitized TiO₂ nanoparticles, fcc₃ catalyzes visible-light-driven succinate production in aqueous suspension. Solar-to-chemical conversion using neutral water as the oxidant is achieved with a photoelectrochemical cell comprising an fcc₃-modified indium tin oxide cathode linked to a cobalt phosphate-modified BiVO₄ photoanode. The results reinforce new directions in the area of artificial photosynthesis, in particular for solar-energy-driven synthesis of organic chemicals and commodities, moving away from simple fuels as target molecules