One-step green synthesis of cuprous oxide crystals with truncated octahedra shapes via a high pressure flux approach

Cuprous oxide (Cu2O) was synthesized via reactions between cupric oxide (CuO) and copper metal (Cu) at a low temperature of 300 deg. C. This progress is green, environmentally friendly and energy efficient. Cu2O crystals with truncated octahedra morphology were grown under high pressure using sodium hydroxide (NaOH) and potassium hydroxide (KOH) with a molar ratio of 1:1 as a flux. The growth mechanism of Cu2O polyhedral microcrystals are proposed and discussed. - Graphical Abstract: The Cu2O crystals with truncated octahedral shape were one-step synthesized in high yield via high pressure flux method for the first time, which is green and environmentally friendly. The mechanisms of synthesis and crystal growth were discussed in this paper. Highlights: → Cuprous oxide was one-step green synthesized by high pressure flux method. → The approach was based on the reverse dismutation reactions between cupric oxide and copper metal. → This progress is green, environmentally friendly and energy efficient. → The synthesized Cu2O crystals were of truncated octahedra morphology.