Synthesis, Characterization, Electronic Structure, and Photocatalytic Behavior of CuGaO2 and CuGa1–xFexO2 (x = 0.05, 0.10, 0.15, 0.20) Delafossites

Abstract

The photochemical reduction of CO2 to chemicals, such as CO and CH4, is a promising carbon management approach that can generate revenue from chemical sales to help offset the costs associated with the use of carbon-management technologies. Delafossite materials of the general stoichiometry ABO2 are a new class of photocatalysts being considered for this application. Symmetry breaking in these materials, by chemical substitution, modifies the band structure of the solid, which enhances optical transitions at the fundamental gap and can therefore be used to engineer the photocatalytic performance of delafossites by adjusting the alignment of band edges with chemical redox potentials and enhancing the optical activity associated with the production of photoexcited charge carriers. The photochemical activity of CuGaO2 and CuGa1–xFexO2 (x = 0.05, 0.10, 0.15, 0.20) for the reduction of CO2 has been studied. Our results show that the CuGaO2 materials investigated have an optical gap at ∼3.7 eV in agreement with...