High-performance artificial leaf: from electrocatalyst design to solar-to-chemical conversion

Abstract

The development of sustainable energy sources is critical to the continued progress of humanity in the face of a growing population and escalating energy demands. The conversion of solar energy into chemical feedstocks provides a long-term energy storage strategy, opening the way for the synthesis of fuels and chemicals. Usually, there are three categories that mimic natural photosynthesis, involving direct photocatalysis (PC), photoelectrocatalysis (PEC), and photovoltaic–electrocatalysis (PV–EC). In terms of solar-to-chemical conversion, PV–EC that couples efficient electrocatalysts and state-of-the-art photovoltaic solar cells is more appealing. In this configuration, one or more light absorbers are used to provide photo-generated electrons for the electrocatalytic reduction reactions, such as the hydrogen evolution reaction (HER), CO₂ reduction reaction (CO₂RR) and N₂ reduction reaction (NRR), while the photo-generated holes are used for the oxygen evolution reaction (OER). This review discusses the recent advances in electrocatalyst design and device construction for solar-driven conversion of small molecules into value-added chemicals in terms of activity, selectivity, and stability. Finally, we discuss the existing issues and future outlook of this promising field.