Z-scheme photocatalytic systems for carbon dioxide reduction. Where are we now?

Transforming CO${}_2$ into fuels by utilizing sunlight is promising to synchronously overcome global warming and energy-supply issues. It is crucial to design efficient photocatalysts with intriguing features such as robust light-harvesting ability, strong redox potential, high charge-separation, and excellent durability. Hitherto, a single-component photocatalyst is incapable to simultaneously meet all these criteria. Inspired by natural photosynthesis, constructing artificial Z-scheme photocatalysts provides a facile way to conquer these bottlenecks. In this review, we firstly introduce the fundamentals of photocatalytic CO${}_2$ reduction and Z-scheme systems. Thereafter we discuss state-of-the-art Z-scheme photocatalytic CO${}_2$ reduction, whereby special attention is placed on the predominant factors that affect photoactivity. Additionally, further modifications that are important for efficient photocatalysis are reviewed. (© 2020 Wiley‐VCH GmbH)