ABSTRACT
Shape control of inorganic nanoparticles generally requires the use of surfactants or ligands to passivate certain crystallographic planes. Additive free shape control methods utilize the differences in the growth rates of crystallographic planes. We combined this approach with the sonochemical method to synthesize copper hydroxysulfate (Brochantite) with morphologies ranging from flowers, to bricks, belts and needles. Sodium peroxydisulfate, which was used as the sulfate and hydroxide source, was decomposed thermally and/or sonically under various pH and temperature conditions. The relative release rates of the sulfate and hydroxide anions determined the final form of the crystals. This technique yielded products even at acidic pH, marking a distinction from the literature reactions, which start with stoichiometric amounts of sulfate and hydroxide anions and yield only a single crystal morphology.
Subject(s)
Copper Sulfate/chemical synthesis , Copper Sulfate/radiation effects , Sonication/methods , Water/chemistry , High-Energy Shock Waves , Particle Size , Radiation DosageABSTRACT
CuS hollow spheres were quickly synthesized under mild conditions with spherical aggregates of Cu(2)O nanoparticles as sacrificial templates. The mechanism involved in the synthesis process has been studied using transmission electron microscopy, high-resolution transmission electron microscopy, scanning electron microscopy, X-ray diffraction, thermal gravimetry, and Fourier transform infrared spectra. The results show that the formation of loose aggregates of Cu(2)O nanoparticles is the key to the fast synthesis of hollow spheres at low temperature. The thickness of the shell can be controlled easily by adjusting the aggregation degree of the Cu(2)O nanoparticles.
