PREPARATION AND GROWTH-MECHANISM OF UNIFORM COLLOIDAL COPPER-OXIDE BYTHE CONTROLLED DOUBLE-JET PRECIPITATION

Monodispersed crystalline CuO particles of different morphologies were synthesized by the controlled double-jet precipitation (CDJP) techniq ue using NaOH and Cu(NO3)(2) as the reactants. The effects of temperat ure, reaction time, pH, and the concentrations of chemicals on the cha racteristics of final products were investigated. With lower [NaOH]/[C u(NO3)(2)] molar ratios and temperatures, colloidal gerhardtite Cu-2(O H)(3)NO3 precipitated, while tenorite CuO particles of various morphol ogies were obtained at higher temperatures and [NaOH]/[Cu(NO3)(2)] rat ios. Time resolved electron microscopy indicated that nanosized primar y particles formed immediately after mixing the reactants, followed by aggregation into larger uniform particles of submicrometer size. (C) 1997 Academic Press