A review of the emerging role of engineered nanomaterials as nanoadsorbents in enhanced drinking water defluoridation

Abstract Access to safe drinking water remains a serious global concern, especially in regions where high levels of naturally occurring fluoride put millions at risk of serious health issues. Among the various treatment options, adsorption has emerged as a reliable and practical method for removing excess fluoride, largely due to its affordability, simplicity, and adaptability. In recent years, nanomaterials have gained significant attention for their exceptional ability to adsorb fluoride thanks to their high surface area, chemical flexibility, and fast reaction times. This review takes a closer look at how different types of nanomaterials, including metal oxides, carbon-based structures, aluminium derivatives, magnetic composites, and advanced core–shell designs, are shaping the future of defluoridation. We explore not just how well these materials perform in lab conditions, but also their underlying mechanisms, such as how they bond with fluoride, how particle size affects adsorption, and how surface chemistry impacts selectivity. Special attention is given to graphene-based materials, which show remarkable potential but come with real-world challenges like cost, regeneration, and environmental impact. By connecting material science with practical water treatment concerns, this review aims to provide a direction to future research and innovation toward scalable, sustainable solutions that bring safe water to more people. Graphical Abstract