Discovery of Novel Delafossite-type Compounds Composed of Copper(I) Lithium Titanium with Photocatalytic Activity for H₂ Evolution under Visible Light

Abstract

Novel delafossite-type compounds Cu(Li_1/3Ti_2/3)O₂ with 3R- and 2H-type structures have been discovered through the reaction between Li₄Ti₅O₁₂ and Cu₂O. Cu(Li_1/3Ti_2/3)O₂ is the first Cu(I)-titanate containing no dⁿ (n = 1–9) metal ions. It has been found that Cu(Li_1/3Ti_2/3)O₂ with a band gap of 2.1 eV functions as a photocatalyst for H₂ evolution under visible light irradiation.