Development and integration of gate insulators that offer a low equivalent oxide thickness (EOT) while maintaining a physically thicker layer are critical for advancing transistor technology as device dimensions continue to shrink. Such materials can deliver high gate capacitance and yet reduce gate leakage, thereby minimizing static power dissipation without compromising performance. These insulators should also provide the necessary interface quality, thermal stability, switching endurance, and reliability. Here, we demonstrate that nanosheets derived from titanium diboride (NDTD), synthesized at room temperature using a scalable dissolution-recrystallization method, exhibit EOT ∼ 2 nm irrespective of the physical thickness when used as top gate dielectrics for monolayer MoS