Preparation of nanometer-sized manganese oxides by intercalation of organic ammonium ions in synthetic birnessite OL-1

Potassium manganese oxide materials having the synthetic birnessite structure K-OL-1 were synthesized by reduction methods. K-OL-1 has been ion-exchanged with H⁺ to produce H-OL-1, which was utilized in further intercalating reactions. The tetraalkylammonium hydroxides including tetramethylammonium hydroxide, tetraethylammonium hydroxide, tetrapropylammonium hydroxide, and tetrabutylammonium hydroxide and diamines such as ethylenediamine, 1,6-diaminohexane, and 1,10-diaminooctane were used to intercalate H-OL-1. Elemental analyses, X-ray diffraction, FT-IR spectroscopy, scanning electron microscopy and energy-dispersive X-ray analysis, UV-vis spectroscopy, and transmission electron microscopy have been used to characterize the samples. Structural models of both wet and dry samples are given. The intercalation and deaquation processes of TAA and DA-OL-1 were studied. Their particle sizes were determined and nanometer-sized TAA-OL-1 samples were prepared in TAA systems.