Self-assembled structures of CuO primary crystals synthesized from Cu(CH3COO)2–NaOH aqueous systems

This paper reports self-assembled microstructures of CuO particles synthesized from Cu(CH3COO)2–NaOH aqueous systems. The assembled CuO particles are composed of CuO primary single crystal nanoparticles, which are bounded by three {100} planes. The morphology of these CuO primary crystals is determined by the surface energy of the exterior crystallographic planes and influenced by NaOH concentration in the solution. The electrical polarity on opposite surfaces of the {100}-CuO primary crystals facilitates their self-aligned assembly into various microstructures. Depending on the NaOH concentration in the solution, different 3D or 2D structures of CuO particles are formed, including lenticular plates, elliptical plates and pseudo-3D structures, as influenced by selective adsorption of OH− ions on the exterior crystal planes of CuO primary crystals.