A General Preparation of Solid Solution-Oxide Heterojunction Photocatalysts through Metal-Organic Framework Transformation Induced Pre-nucleation

Solid solution-oxide heterostructures combine the advantages of solid solution and heterojunction materials to improve electronic structure and optical properties by metal doping, and enhance charge separation and transfer in semiconductor photocatalysts by creating a built-in electric field. Nevertheless, the effective design and synthesis of these materials remains a significant challenge. Here, we develop a generally applicable strategy that leverages the transformable properties of metal-organic frameworks (MOFs) to prepare solid solution-oxide heterojunctions with controllable structural and chemical compositions. The process consists of three main steps. First, MOFs with different topological structures and metal centers are transformed, accompanied by pre-nucleation of a metal oxide. Second, solid solution is prepared through calcination of the transformed MOFs. Finally, a heterojunction is formed by combining solid solution with another metal oxide group through endogenous overflow. DFT calculations and study on carrier dynamics show that the structure of the material effectively prevents electrons from returning to the bulk phase, exhibiting superior photocatalytic reduction performance of CO2. This study is expected to promote the controllable synthesis and research of MOF-derived heterojunctions.