Towards Solar Factories: Prospects of Solar‐to‐Chemical Energy Conversion using Colloidal Semiconductor Photosynthetic Systems

Abstract Solar‐to‐chemical (STC) energy conversion is the fundamental process that nurtures Earth's ecosystem, fixing the inexhaustible solar resource into chemical bonds. Photochemical synthesis endows plants with the primary substances for their development; likewise, an artificial mimic of natural systems has long sought to support human civilization in a sustainable way. Intensive efforts have demonstrated light‐triggered production of different solar fuels, such as H2, CO, CH4 and NH3, while research on oxidative half‐reactions has built up from O2 generation to organic synthesis, waste degradation and photo‐reforming. Nevertheless, while extensive utilization of the radiant chemical potential to promote a manifold of endergonic processes is the common thread of such research, exploration of the chemical space is fragmented by the lack of a common language across different scientific disciplines. Focusing on colloidal semiconductor materials, this Viewpoint discusses an inclusive protocol for the discovery and assessment of STC redox reactions, aiming to establish photon‐to‐molecule conversion as the ultimate paradigm beyond fossil energy exploitation.