Hydrothermal synthesis of uniform cuprous oxide microcrystals with controlled morphology

Cuprous oxide (Cu2O) with controlled morphology was synthesized via a hydrothermal method by reducing copper nitrate with formic acid. Reactant concentration, reaction temperature, and time show strong effects on the phase formation and morphology of the products. The products were characterized by X-ray power diffraction (XRD), scanning electron microscope (SEM), and UV-vis diffuse reflectance spectroscopy. The possible crystal growth processes have been proposed. The band gap versus different morphology was also studied.