Formation and characterization of two-dimensional arrays of silver oxide nanoparticles under langmuir monolayers of n-hexadecyl dihydrogen phosphate

Abstract

Two-dimensional arrays of silver oxide nanoparticles were prepared by oxidation of silver nanoparticle arrays in air. The silver nanoparticle arrays were formed by illuminating the composite Langmuir monolayers of n-hexadecyl dihydrogen phosphate (n-HDP)/ethyl stearate (ES)/Ag+ at the air-water interface by daylight. The average diameters of the nanoclusters is found to be 2.32 ± 0.89, 2.97 ± 0.78, and 4.94 ± 0.57 nm, respectively, depending on the experimental conditions. X-ray photoelectron spectroscopy (XPS), UV-vis spectroscopy and high-resolution transmission electron microscopy (HRTEM) investigations indicate the formation of silver oxide nanoparticles. The possible formation mechanism of the 2D arrays should be attributed to the templating effect of parallel aligned linear supramolecular rows of n-HDP formed at the air-water interface.