The mixed-ligand strategy for structural modification of MOF materials to enhance the photocatalytic degradation and adsorption of organic pollutants: A review

Pollution of water raises many concerns for the community because these substances are considered hazardous and can be detrimental to the environment. Waste such as dyes and pesticide residues are the most significant contributors to organic pollution. These hazardous and toxic materials must be properly removed from the environment to ensure and protect human health, safety, and the environment. Adsorption and photodegradation are two effective water purification techniques with high efficiency, economy, and ease of operation, promising environmental remediation through efficient energy use. Metal-organic frameworks (MOFs) that combine metal ions with organic ligands have diverse physical and chemical properties, making them excellent materials for removing toxic pollutants. MOFs possess unique structural properties and are utilized in the latest technological advancements for removing pesticides, heavy metal ions, pharmaceutical waste, and dyes. The functionalization, modification, defects, and deformations of adsorbents can improve the adsorption and photocatalytic performance of MOFs. Several essential factors related to MOF synthesis have been studied concerning structural properties, the basis of linker functionalization, the synthetic strategy of MIX-MOF assembly, mixed ligands, and framework defects, which can improve MOF performance in certain areas. Several topics will be discussed in this review, including MOFs, the strategy of using mixed ligands in MOF synthesis, and their application for treating environmental pollution.