Bottom-up preparation of porous metal-oxide ultrathin sheets with adjustable composition/phases and their applications.

A facile bottom-up synthesis approach is developed to prepare porous metal-oxide ultrathin sheets, e.g., SnO(2), Fe(2)O(3), and SnO(2)-Fe(2)O(3), with thicknesses of ∼5 nm. Graphene sheets are used as the sacrificing template. Such a process can be extended to the synthesis of multiphased porous metal-oxide thin sheets. These porous thin sheets show interesting applications as gas sensors, effective platforms for matrix-assisted laser desorption/ionization-time-of-flight mass spectrometry, and supercapacitors.