Room Temperature Engineering Crystal Facet of Cu(2)O for Photocatalytic Degradation of Methyl Orange

Cuprous oxide (Cu(2)O) has received enormous interest for photocatalysis owing to its narrow band gap of 2.17 eV, which is beneficial for visible-light absorption. In this work, we succeeded in synthesizing Cu(2)O nanocrystals with two morphologies, cube and sphere, at room temperature via a simple wet-chemistry strategy. The morphologies of Cu(2)O change from cube to sphere when adding PVP from 0 g to 4 g and the mainly exposed crystal faces of cubic and spherical Cu(2)O are (100) and (111), respectively. The photocatalytic properties of the as-prepared Cu(2)O were evaluated by the photocatalytic degradation of methyl orange (MO). Cubic Cu(2)O(100) showed excellent photocatalytic activity. After the optical and photoelectric properties were investigated, we found that cubic Cu(2)O(100) has better photoelectric separation efficiency than spherical Cu(2)O(111). Finally, the possible mechanism was proposed for cubic Cu(2)O(100) degrading MO under visible light.