An EXAFS study of the amorphous cuprum hydroxide

It was shown that for the bulk cuprum hydroxide the amorphisation is determined only by an excess of water without which the Cu(OH)2 presents in the crystal form only. In the case of the supported cuprum hydroxide, the amorphisation is achieved by stabilisation of the hydroxide particles on a high dispersed silica surface under low concentration of the cuprum ions, so that the sizes of the supported complexes are small. The data obtained suggests that the cuprum from dilute solution (4 × 10−3M) under low values of pH is adsorbed on the surface SiO2 as a polymer-like structure similar to that of Cu(OH)2 rather than as isolated ions. This inference is confirmed by previously obtained results on adsorption of Cu2+ on TiO2.