Optimised Synthesis of Rhombic dodecahedral Cu2O Nanoparticles: A Pathway to Superior Morphological Control

Cuprous oxide (Cu2O) nanoparticles hold significant promise for photocatalytic applications due to their narrow bandgap and high surface reactivity. This study focuses on the synthesis of rhombic dodecahedral Cu2O (RD-Cu2O) nanoparticles, totally enclosed by {110} facets, known to exhibit superior photocatalytic performance over the other low-index crystallographic facets. The precise control over the synthesis conditions can significantly enhance the exposure of this highly active face and therefore improve the catalytic performance of Cu2O nanoparticles, making them superior for applications in pollutant degradation, organic reactions, and artificial photosynthesis. We systematically optimised the synthesis parameters, including reactants concentration, pH and other reaction conditions, to achieve a significant scale up of well-defined RD- Cu2O nanoparticles production, strictly necessary for the use of this photocatalyst on a larger scale. The optimised and scaled up synthesis require 2.0 mmol of CuCl2, 6.0 mmol of Sodium dodecyl sulphate (SDS), 9.6 mmol of NH2OH ⋅ HCl and 7.0 mmol of NaOH added in this order to 400 ml of water at 25 °C. The optimised nanoparticles demonstrated a narrow size distribution and a high degree of crystallographic control. Characterisation techniques such as FESEM, XRD, EPR, UV-Vis spectroscopy, and XPS confirmed the improved morphological and structural properties of the synthesised RD-Cu2O nanoparticles.