Trace to the Source: Self-Tuning of MOF Photocatalysts

Benefitting from ultra-high porosity, large specific surface area (SSA), and rich active sites, metal-organic frameworks (MOFs) have emerged as a star material in energy and environment related applications, especially in photocatalysis. In comparison with conventional photocatalysts, MOFs can be customized in terms of electronic structure, photo-responsiveness, and morphological dimensions by rational design, which means that MOFs eliminate the need for other species to achieve enhanced photocatalytic performance, such as metals, compounds, and polymers, which may introduce extra costs, be time-consuming, be multi-phase, or have an unclear mechanism. Most previous review works related to MOF photocatalysis have mixed self-tuning and assisted-tuning, which often gives an incomplete understanding. In this work, the self-tunning of MOFs by analyzing component (as clusters, ligands, and inclusions), defect (defect engineering, as linkers, clusters, and oxygen vacancies (OVs), and crystal (as facets, dimensions, and amorphization) is summarized. Then, outstanding examples of these strategies applied to water redox, CO2/N-2 reduction, organic conversion, and environmental treatment are discussed. Finally, the opportunities and challenges faced in the self-tuning of MOFs are analyzed from different perspectives. This paper is a comprehensive and systematic review on the self-tuning of MOFs to enhance photocatalytic activity.