Synthesis and enhanced photocatalytic activity of regularly shaped Cu2O nanowire polyhedra

A series of unique nanowire superstructures, Cu2O nanowire polyhedra, have been synthesized through a cost-effective hydrothermal route. Three types of nanowire polyhedra, namely octahedra, concave octahedra, and hexapods, were formed in high morphological yields (90%) by reducing cupric acetate with o -anisidine or o -phenetidine in the presence of carboxylic acids. The architectures of these Cu 2 O nanowire polyhedra were examined by electron microscopy, which revealed ordered, highly aligned Cu 2 O nanowires within the polyhedral outlines. The growth of the Cu 2 O nanowire polyhedra is controlled by the orientation and growth rates of the nanowire branches which are adjusted by addition of carboxylic acids. Compared to the Cu 2 O samples reported in the recent literature, the Cu 2 O nanowire octahedra exhibit notably enhanced photocatalytic activities for dye degradation in the presence of H 2 O 2 under visible light, probably due to the high-density charge carriers photoexcited from the branched nanowires with their special structures. Additionally, the discussion in the recent literature of the photocatalytic activity of Cu 2 O in the absence of H 2 O 2 for direct photodegradation of dyes seems questionable.