Recent Advances in High-Entropy Oxides for Photocatalytic Applications

This paper provides a comprehensive overview of high-entropy oxides (HEOs) and their applications in photocatalysis. The unique functionality of HEOs stems from their distinct crystal and electronic structures, achieved through the substitution of one cation with multiple cations in the lattice. This structural innovation has attracted significant attention, with increasing studies since 2019. To date, approximately 38 papers on HEOs in photocatalysis have been reported, indicating that this research is still in its early stages. Some HEOs exhibit photocatalytic performance comparable to that of conventional oxides like TiO2 and SrTiO3, highlighting their potential. This Perspective discusses the synthesis methods, crystal structures, and photocatalytic properties of HEOs, emphasizing their advantages through specific examples. Additionally, it proposes future research directions, including the development of innovative materials and prediction of properties using first-principles calculations and machine learning, to advance the application of HEOs in photocatalysis.