Recent Progress in Designing Nanomaterial Biohybrids for Artificial Photosynthesis.

In natural photosynthesis, solar energy is utilized to convert water and CO into energy-rich compounds. However, in practice, the maximum quantum efficiency of natural photosynthesis is limited to 6.0%. Conversely, artificial photosynthesis (AP) systems utilize solar energy to convert CO into biosynthetic solar fuels and value-added chemicals. To mimic natural photosystems, AP integrates light-harvesting chemical catalysts with the enzyme-mediated biological catalysis occurring in microorganisms. Similar to solar energy-based optoelectronic power sources, AP has also been recognized as a promising option for reducing carbon emissions generated by the fossil fuel-based power sector. Typical quantum efficiency of AP is 5-10%; in some cases, it exceeds 20%. Recent advancements have focused on nanomaterial biohybrids (NBHs), combining nanomaterial-based photocatalysts/photosensitizers with microorganisms/enzymes for enhanced oxidation/reduction reactions. The synergistic interaction between nanomaterials and microorganisms, facilitated by their comparable size and tunable surface properties, enables improved solar energy absorption, charge separation, and conversion. NBHs offer a versatile platform for sustainable solar energy harvesting and conversion, overcoming the limitations of natural and fully abiotic photosynthesis systems. This review highlights recent breakthroughs in diverse platforms of sunlight and visible light-driven NBH-based AP systems for CO fixation, H production, water splitting, and value-added chemical synthesis. The synthesis strategies, operating mechanisms, and challenges are highlighted.