Interfacial Photoelectrochemistry in Organic Synthesis

Photoelectrodes have traditionally enjoyed widespread attention as heterogeneous catalysts for the activation of water and CO₂ in energy research, while photoelectrochemistry with homogeneous molecular catalysts dominates the activations of more complex molecules in organic synthesis. Nonetheless, interfacial photoelectrochemistry (iPEC) offers great benefits to organic synthesis, including catalyst cost-efficiency, reusability, and stability. This review aims i) for a comprehensive collection of historical and recent examples of iPEC and ii) to present the field in manner and language accessible to synthetic chemists. Conceptual comparisons from photoelectrodes to homogeneous (electro-activated) photocatalysts to dye-sensitized photoelectrodes will be drawn, with advantages and limitations of each catalyst archetype discussed. Surface techniques for fabrication of photoelectrodes will be introduced. Future semiconductor photoelectrode materials, substrate targets, and conceptual challenges in the field will be highlighted.