Decoupled Artificial Photosynthesis.

Natural photosynthesis (NP) generates oxygen and carbohydrates from water and CO utilizing solar energy to nourish lives and balance CO levels. Following nature, artificial photosynthesis (AP), typically, overall water or CO splitting, produces fuels and chemicals from renewable energy. However, hydrogen evolution or CO reduction is inherently coupled with kinetically sluggish water oxidation, lowering efficiencies and raising safety concerns. Decoupled systems have thus emerged. In this review, we elaborate how decoupled artificial photosynthesis (DAP) evolves from NP and AP and unveil their distinct photoelectrochemical mechanisms in energy capture, transduction and conversion. Advances of AP and DAP are summarized in terms of photochemical (PC), photoelectrochemical (PEC), and photovoltaic-electrochemical (PV-EC) catalysis based on material and device design. The energy transduction process of DAP is emphasized. Challenges and perspectives on future researches are also presented.