Artificial photosynthetic processes using carbon dioxide, water and sunlight: can they power a sustainable future?

Solar-driven carbon dioxide reduction (CO₂RR) mimics natural photosynthesis by harnessing sunlight to convert water and CO₂ into chemicals, thereby enabling the storage of solar energy in energy-dense molecules for on-demand use. With the accelerated advancement of solar-driven CO₂-to-chemicals conversion technologies, this approach holds promise for contributing to the realisation of a zero-carbon society, a target increasingly prioritised by governments worldwide. Here, we argue that despite these promising developments, substantial challenges persist at both the material and system levels, extending beyond the catalytic process itself to include upstream CO₂ capture and downstream product separation and purification. We also present a techno-economic assessment of current solar-driven CO₂RR platforms and conclude that they remain well below the thresholds necessary for commercial-scale deployment. To address this gap, we propose several directions for future progress. From a fundamental perspective, the integration of machine learning models and data-driven approaches, in conjunction with operando spectroscopic techniques, may accelerate the discovery and optimisation of materials by providing rational design principles. From a practical standpoint, the deployment of CO₂RR systems in non-traditional environments, such as desert regions or aquatic platforms, and their coupling with alternative oxidation reactions (e.g., waste photoreforming) may improve system viability by reducing the capital cost and extracting added value from oxidation products. We hope that these analyses and proposals will help advance next-generation solar fuel production systems and enhance their prospects for real-world applications.