From metal-organic frameworks (MOFs) to metal-doped MOFs (MDMOFs): Current and future scenarios in environmental catalysis and remediation applications

Metal-organic frameworks (MOFs) represent an impressively ordered and crystalline class of hybrid materials of organic ligands and metal clusters or ions. MOFs are associated with numerous unique properties that make them materials of choice for different biological, environmental and industrial uses. Recently, the synthesis, characterization and application of doped MOFs, especially metal-doped MOFs (MDMOFs), are gaining particular attention because of their magnified properties and performance. This review aims to describe the collection of different applications of doped MOFs for the first time. In this report, many applications of MDMOFs such as gas reduction and storage, wastewater treatment (as adsorbents), catalysis (as catalysts), sensing, energy and other areas are surveyed and summarized. A literature survey revealed that MDMOFs can improve the reaction rates up to 57 times and can be recycled up to 7 times with more than 80% efficiency. More so, doping can also remarkably increase the gas intake potential of MOFs up to 450% (toluene), 63% (H₂), and 1700% (CO₂). The MDMOFs are also used as effective catalysts for gas reduction especially for CO₂. Moreover, faradaic efficiencies as high as 74% are possible with doped MOFs. The adsorption capacities for MO and CR have been reported to be 23.4 and 31.4 % higher as compared to parent MOFs. The doping also improves the sensing and biosensing properties of MOFs for humidity, ethanol, and OTA detection. The improved properties and performance of MDMOFs as compared to pristine MOFs are attributed to the increase in the number of adsorption sites, optimized electronic structure and chemically active surface area.