Simultaneous detection and removal of fluoride from water using smart metal-organic framework-based adsorbents

The fluoride ion is usually added to drinking water because of its prominent role in treating osteoporosis and improving dental health. However, fluoride contents over the optimal level (>1.5 ppm) in water resources has been found to have harmful effects on human health such as bone and dental fluorosis, Alzheimer's syndrome, DNA damage, infertility, kidney failure, acute gastric problems, thyroid disorder, brain damage, and even cancer. Therefore, sensitive and selective detection of fluoride ions and their removal from drinking water are of great significance. The unique features of metal–organic frameworks (MOFs), such as chemical activities, a broad range of functionalities, high stability, and modification opportunities for specific molecule detection or adsorption, make them broadly applicable in detecting and removing fluoride ions from water. The present review summarizes recent developments for detecting and removing fluoride ions from water by MOFs. The recent progress in fluoride removal via MOFs will be discussed in depth. The actual adsorption performance of various MOFs toward fluoride will be elaborated using partition coefficient (PC), independent of operating conditions. The detection and adsorption mechanisms are fleshed out comprehensively, providing insights and a roadmap to address current challenges and shed light on future study directions.