Microstructure and Electronic Properties of Low-Index Stoichiometric CuFeO2 Surfaces: DFT Calculations

As a potential and efficient photocatalyst, CuFeO 2 has attracted increasing attention. However, the surface structures and properties of CuFeO 2 have not been investigated in detail until now. In this work, the density functional theory calculations have been used to analyze the microstructures and electronic structures of low-index stoichiometric CuFeO 2 surfaces. It is evident that atoms on the outermost surfaces with dangling bonds lead to the presence of surface states. The surface states at the valence band maximum and conduction band minimum facilitate the separation of photogenerated electron-hole pairs, in the cases of relaxed (012) and (110) surfaces. In contrast, the continuous surface states in the forbidden band increase the recombination of photogenerated electron-hole pairs, in the cases of relaxed (001), (100) and (101) surfaces. In all considered surfaces of CuFeO 2 , the relaxed (001) surface is the most stable, due to the minimum dangling bond density. According to the Wulff rule, the thermodynamic equilibrium shape of CuFeO 2 is finally constructed. Among them, the {001} surface is the dominating exposed crystal facet (49.54%). These findings reveal the correlation between the surface microstructure and photocatalytic performance of CuFeO 2 and provide further theoretical support for the subsequent development of more efficient CuFeO 2 -based photocatalysts.