Chapter 7: Bridging Homogeneous and Heterogeneous Systems—Photoelectrodes for CO₂ Electrochemical Conversion Check Access

The energy crisis and environment pressure have driven people to search for a sustainable way for society to develop. To achieve this goal, artificial photosynthesis is a promising choice, where the CO₂ reduction reaction (CO₂RR) happens on a semiconductor catalyst driven by sunlight. CO₂, viewed as a nasty waste product, can also serve as an available carbon source to produce value-added chemicals (e.g., methanol, ethylene, formic acid and so on) through the CO₂RR. In pursuit of high efficiency for the CO₂RR, it is essential to design effective and stable semiconductor photoelectrodes via optimizing the light harvest, charge separation and transfer, and surface reaction. Besides the efficiency, CO₂RR also faces other challenges including CO₂ solubility and product selectivity. In this chapter, we will discuss these issues from three aspects of the photoelectrochemical (PEC) process: the physico-chemical process at the photoelectrode, the surface co-catalyst choice, and the influence of the electrolyte solution.