The Progress of Electrochromic Materials Based on Metal Organic Frameworks

Electrochromic (EC) materials can reversibly transform their optical properties (including transmittance, reflectance, absorption, color, etc.) under an external electric field and have shown great potential applications in smart devices. Metal-organic frameworks (MOFs) are porous crystalline materials composed of metal centers and organic bridging ligands through coordination bonds. Considering the unlimited possibility of inorganic and organic components, large specific surface area, unique permanent porosity, facile structural and surface properties, MOFs have both the characteristics of organic-inorganic hybridization and rich nanoporous structure, which inherently meets the requirements for improving the performance of EC materials, and is expected to become a new generation of excellent EC materials. This review aims to systematically summarize the latest advances in MOFs-based EC materials, including four types, MOFs with redox active linkers, MOFs with redox active metal centers, MOFs with entrapped redox active guest molecules in their pores or channels, and MOF derivatives. Hopefully, this review can inspire more and more researchers to enrich the MOF-based EC materials to fully release the application potential of MOFs as EC materials and provide assistance for the future smart devices.