Photoelectrochemical Heterogeneous Catalysis: From Single Molecule Oxidation Toward C─X Bond Formation.

Photoelectrocatalytic (PEC) organic synthesis has emerged as a promising platform for sustainable chemical manufacturing by synergistically integrating light and electrical energy. The fundamental mechanism involves the generation of electron-hole pairs in semiconductor photoelectrodes, where photogenerated holes drive oxidative transformations at the anode and electrons facilitate reductive reactions at the cathode. This approach enables precise control over reaction pathways under mild conditions, offering enhanced energy efficiency, improved selectivity and elimination of stoichiometric oxidants. This review comprehensively summarizes the rapid development of PEC organic synthesis, beginning with its fundamental principles and common photoelectrode fabrication techniques. Recent advances are then outlined across two major domains: the photoanode-mediated oxidation of single molecules (e.g., alcohols, biomass-derived platform chemicals, alkenes, and C─H bonds) and photoelectrochemical cross-coupling reactions for constructing C─X (X = C, N, P, Cl, and Br) bonds. Finally, a forward-looking perspective on critical challenges and future directions are discussed, which will significantly improve the insight for future development of PEC organic synthesis.