Crystal-plane effect of Cu2O templates on compositions, structures and catalytic performance of Ag/Cu2O nanocomposites

Abstract

Various Ag/Cu₂O nanocomposites were prepared via the galvanic replacement reaction involving AgNO₃ reacting respectively with uniform Cu₂O cubes and octahedra. Their compositions and structures were comprehensively characterized microscopically and spectroscopically. The results reveal that the crystal plane of employed Cu₂O solid templates determines the compositions and structures of the resulting Ag/Cu₂O nanocomposites. A smooth surface mixed with nanoneedles or nanosheets of Ag/c-Cu₂O structures was fabricated on Cu₂O cubes while flocculent Ag/o-Cu₂O structures were fabricated on Cu₂O octahedra. The catalytic performance of Ag/Cu₂O nanocomposites were evaluated in CO oxidation with excess O₂. In situ surface restructuring occurs on various Ag/Cu₂O nanocomposites to form Ag–CuO/Cu₂O nanocomposites. The catalytic activity of the resulting Ag–CuO/Cu₂O nanocomposites depends on the structures of CuO and Ag that are affected by the original crystal plane of Cu₂O solid templates and the Ag loading. These results broaden the crystal-plane effect of Cu₂O nanocrystals as solid templates for synthesis of multicomponent nanocomposites via liquid–solid interfacial reactions.