Efficient and Clean Photoreduction of CO₂ to CO by Enzyme-Modified TiO₂ Nanoparticles Using Visible Light

A hybrid enzyme-nanoparticle system is described for achieving clean reduction of CO(2) to CO using visible light as the energy source. An aqueous dispersion of TiO(2) nanoparticles modified by attachment of carbon monoxide dehydrogenase (CODH) and a Ru photosensitizer produces CO at a rate of 250 mumol of CO (g of TiO(2))(-1) h(-1) when illuminated with visible light at pH 6 and 20 degrees C.