Synthesis of submicrometer-sized Cu2O with morphological evolution in a one-pot reaction

• The preparation of Cu2O is a simple one-pot reaction using environment-friendly reductants.
• Novel ‘balsam pear’ rod and star shapes of Cu2O were first synthesized at 70 °C.
• Cu2O cubes were prepared at 25 °C with ascorbic acid as a reductant.
• Reaction temperature and PVP dispersant are important to Cu2O morphology.

Different morphologies of Cu2O materials were synthesized with a simple one-pot reaction by adding reductant into a Benedict mixing solution containing copper sulfate, sodium carbonate, and sodium citrate. Effects of reducing agent, dispersant, and temperature on material structures were investigated. Novel ‘balsam pear’ rod and star shapes of Cu2O were obtained at a reaction temperature of 70 °C when glucose was used as a reductant. The cubic shape of Cu2O was prepared at 25 °C with ascorbic acid as a reductant. Moreover, the size of the cube increased and the crystal faces sharpened when the temperature increased. The products were characterized using X-ray diffraction, X-ray photoelectron spectroscopy, scanning electron microscopy, and transmission electron microscopy. The results showed uniform morphology of Cu2O in each condition. The synthesis method is simple, environmentally-friendly, and highly repeatable.