Recent advances in multi-metallic organic frameworks and their derivatives for catalysis, electro-/photocatalysis and sensing applications

Abstract

The growing global demand for advanced porous materials for a wide range of applications has spurred significant interest in metal–organic frameworks (MOFs). These structures are highly valued for their engineering versatility, combined with multifunctionality, vast chemical space, and structural diversity. Various strategies have been developed to enhance the performance of MOFs in different applications, with one of the most promising approaches being the incorporation of multiple metals into their structure to form multi-metallic organic frameworks (MMOFs). MMOFs exhibit outstanding performance compared to MOFs due to the tunable synergistic effect among diverse metals, enabled by precise structural engineering. The simultaneous presence of several metals imparts exceptionally enhanced properties to MMOFs, including active site tunability, which optimizes their catalytic, photocatalytic, and electrocatalytic performance. Additionally, MMOFs exhibit superior sensing capabilities, characterized by higher sensitivity and precision, and demonstrate improved medicinal properties. This review provides a comprehensive, critical view of MMOFs, focusing on their synthesis strategies, challenges, and the specific or preferential role of each metal when they are present in MMOFs. Further, this review also covers their applications in various fields, such as catalysis, photocatalysis, electrocatalysis, electrical energy storage, gas separation, adsorption, sensing, and medicine. Furthermore, the review offers guidelines in the selection of metals for tailoring MMOFs to specific applications. Numerous existing examples show the superior performance of MMOFs compared to single-metal MOFs (SMOFs), underscoring the synergistic effects arising from the combination of multiple metals present in the structure. This favorable synergy makes MMOFs the most efficient material in a wide range of technological and industrial applications.