Sustainable synthesis strategies of metal-organic frameworks (MOFs) using unconventional precursors: Advances and challenges

Metal-Organic Frameworks (MOFs) are a new type of porous material with large surface areas, configurable porosity, and with potential for a wide range of applications due to their chemical and structural tunability. They are also observed to have diverse applications in gas storage, catalysis, and environmental remediation, among others. However, in traditional MOF synthesis processes, the requirements for high-purity metal salts and conventionally derived organic linkers are often expensive, environmentally unsustainable, and hence hinder MOF commercialisation efforts. Recent progress in MOF synthesis using unconventional precursors is changing the narrative. This review article focuses on recent advances and challenges for the use of naturally occurring inorganic minerals, biomass-derived linkers, and industrial metal-rich waste materials as unconventional feedstocks for MOF synthesis. The study categorises these alternative materials based on their chemical makeup and suitability, while also examining their impact on the structure and function of MOFs. The review's findings suggest that employing unconventional precursors is a viable technique for producing MOFs in an inexpensive and sustainable manner. The study further emphasises the need for more research into the environmental implications of large-scale use, precursor reactivity, and structural integrity. The proposed approach of using alternative or unconventional precursors presents new opportunities for integrating MOF synthesis strategies with circular economy approaches.