The Sun irradiate the Earth with multicolor light, where each color corresponds to a photon (the quantum of radiation) with different energy. All of them can be collected to produce electric power or activate chemical reactions, but the current photovoltaic and photocatalytic technologies cab exploit only a small fraction, which, in the best case, reaches one third of the total available photons.

Solid, liquid or gaseous: these are the different states that matter takes according to external parameters such as temperature and pressure. Let us think of water: in fluid states it cannot be handled like a material, instead ice can even be sculpted. However, when cold, all the matter freezes and stiffens: the molecules themselves move only minimally or very slowly, instead for a solid material to be active it must be endowed with a certain degree of mobility, typical of liquids.

Lithium batteries have changed and are changing our society: almost all the portable devices we know have been developed thanks to these power sources. However, this technology is destined for an increasingly limited use in the future due to the high costs and the scarce availability of some raw materials (such as lithium itself). A possible alternative is the development of rechargeable sodium batteries, a more abundant element in nature.