Synthesis and characterisation of nano-composite copper oxalate powders by a surfactant-free stripping–precipitation process

The use of surfactants has been reported for controlling the particle size and morphology of metal oxalates and hydroxide precipitates in chemical precipitation processes. However, the mechanism involved is not clearly understood and the removal of surfactants from synthesized precipitates can be an obstacle for its large-scale industrial applications. In this study, a surfactant-free stripping–precipitation approach was proposed to synthesize nano-composite powders of copper oxalate. Copper ions were extracted by an organic extractant and oxalic acid-ethanol aqueous solution was employed to strip and precipitate copper. The effect of extractant, organic phase copper concentration, stripping phase ethanol content, temperature and time were investigated. The copper precipitates were characterised by X-ray diffractometry, scanning electron microscopy, transmission electron microscopy and laser particle analyzer.