<p>Heavy metal pollution in water presents persistent and significant risks to the environment and public health that must be addressed through innovative and sustainable solutions. Magnetite nanoparticles (MNPs) have emerged as novel adsorbents due to their tunable surface chemistry, magnetic recoverability, and large surface area. However, their efficiency may be limited especially when used in complex systems without surface functionalization. This review evaluates various coating materials applied to MNPs and the mechanisms through which they improve heavy metal adsorption, selectivity, and material stability. Multiple synthesis and adsorption studies using these coatings for MNP functionalization demonstrate heavy metal adsorption under controlled laboratory-scale systems. The enhanced adsorption performance and stability of functionalized MNPs in comparison to bare counterparts suggest potential applications on a larger scale. Challenges involving cost-effectiveness, regeneration, and adsorption in multi-metal ion systems are yet to be addressed systematically. There is also a need to explore alternative synthesis methods such as electrochemical and one-step approaches to improve scalability, reduced reagent use, and controlled physicochemical properties. The present work consolidates recent developments in the past decade on selected surface coatings for MNPs. It places emphasis on key parameters including adsorption capacity, synthesis conditions, removal efficiency, and specific adsorption mechanisms. The studies evaluated can provide direction for both MNP research efforts and development of industrial-scale treatment systems for heavy metal adsorption in aqueous environments.</p>