TECHNOLOGY FOCUS - INORGANIC CHEMISTRY - Preferred Method: In the method (I), each of the metal oxide nanoparticles has a first end and a second end, which face each other, and the anionic surfactant covers the first end and the second end of the metal oxide nanoparticle, and a side portion of the metal oxide nanoparticle is spaced apart from the anionic surfactant. In the method (I), a coupling reaction rate at the side portion of the metal oxide nanoparticle is faster than that at each of the first end and the second end of the metal oxide nanoparticle. The step of fabricating of the metal oxide sheet comprises horizontally coupling the metal oxide nanoparticles to each other, where the surfactant is provided to upper and lower ends of the metal oxide nanoparticle. The anionic surfactant is dissociated into a cation and an active agent in the precursor solution, the active agent comprises a hydrophobic functional group and a hydrophilic functional group coupled to the hydrophobic functional group, and the metal oxide nanoparticle is disposed between the hydrophilic functional group and the cation of the anionic surfactant. The hydrophilic functional group of the anionic surfactant is provided on the metal cation of the metal oxide nanoparticle, and a cation of the anionic surfactant is provided on the oxygen anion of the metal oxide nanoparticle. The step of forming of the metal oxide nanoparticles and the fabricating of the metal oxide sheet are performed by thermally treating the precursor solution. In the method (II), the cationic surfactant is coupled to at least one metal cation of the metal oxide nanoparticle, and the oxygen anion of the one metal oxide nanoparticle is spaced apart from the cationic surfactant. The oxygen anion of one of the metal oxide nanoparticles is coupled to the other one of the metal oxide nanoparticles. The cationic surfactant is dissociated into a quaternary ammonium cation and an anion in the precursor solution. Preferred Components: The precursor solution comprises zinc nitrate hexahydrate and base solution comprises hexamethylenetetramine. EXAMPLE - No suitable example given.