Photoelectrochemical Alkene Epoxidation with Water Using a TiO₂-Ru Anode

Keywords

photoelectrochemistry - alkene epoxidation - water splitting - bromine-mediated oxidation

Significance

A dye-sensitized photoelectrode was fabricated by the deposition of RuP on a mesoporous TiO₂-coated FTO composite (TiO₂/FTO-RuP). Photoelectrochemical Br-mediated epoxidation of styrenes with water as an oxygen source was examined using TiO₂/FTO-RuP (anode) and platinum (cathode) in the presence of LiBr under 400 nm photoirradiation to afford up to 99 % yield of styrene oxide along with H₂ evolution with high Faradaic efficiency.

Comment

The redox potential of TiO₂/FTO-RuP (Ru^II/III) was determined to be 1.38 V vs. normal hydrogen electrode (NHE) being suitable for the oxidation of LiBr. Aromatic halides (F, Cl, Br) were well tolerated under the photoelectrochemical conditions. RuP exhibited high stability on TiO₂. Thus, the metal-to-ligand charge transfer (MLCT) absorption loss for RuP on TiO₂ was only 5 % during five hours of photoirradiation.

Publication History

Article published online:
20 December 2024