If you remember the early days of computers, you saw some marketing claims that seemed to make sense but quickly evaporated when reality hit - you could store all your recipes, for example, until you realized computers were as loud as a turbo jet and used almost as much energy so it was not wise to keep them on - so keep a box with some index cards in it was much better.
You may feel the same way about adding an invisible layer of nanomaterials to the bottom of a metal put just so you can boil water using a lot less energy. While this increase in efficiency could some day have a big impact on cooling computer chips, and reducing costs for industrial boiling applications, like those early computers, it's best to wait a while before getting rid of the tea kettle.
Bringing water to a boil, and the related phase change that transforms the liquid into vapor, requires an interface between the water and air. In the example of a pot of water, two such interfaces exist: at the top where the water meets air, and at the bottom where the water meets tiny pockets of air trapped in the microscale texture and imperfections on the surface of the pot. Even though most of the water inside of the pot has reached 100 degrees Celsius and is at boiling temperature, it cannot boil because it is surrounded by other water molecules and there is no interface — i.e., no air — present to facilitate a phase change.
