The multiple roles of rare earth elements in the field of photocatalysis

When illuminated by light, different electron transitions occur within the energy levels due to the unique 4f energy level structure of rare earth elements. If rare earth elements are introduced into clean and sustainable photocatalysis technology, the electronic transitions in the energy level structure of the catalyst may change, forming a unique reaction mechanism and producing excellent catalytic performance. In recent years, there have been more and more studies and reports on rare earth photocatalysts due to the large number and different properties of rare earth elements. It is essential to collate and summarize these reports to gain a comprehensive understanding of their functions and applications. This article presents a review of the role and application scope of rare earth photocatalysts and provides a broad outlook on their potential future uses. We hope that this work can provide a new perspective for the development and design of novel and efficient rare earth photocatalysts. The role and classification of rare earth elements in photocatalysts are summarized, with the aim of providing suggestions for the future development of rare earth photocatalysts.