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Mn co-precipitation method combined with Raman spectroscopy were used to determine trace heavy metals (copper, zinc, cadmium and lead) in water sample. Different concentrations of heavy metals including copper, zinc, cadmium and lead in water samples were separated and enriched by Mn²⁺-phen-SCN- ternary complex co-precipitation procedure. The Raman spectra of co-precipitation sediments were collected using confocal micro-Raman spectrometry. Different preprocessing treatments and regression calibration methods were compared. The best models using partial least squares regression (PLS) of copper, zinc, cadmium and lead were built with a correlation coefficient of prediction (R_p) of 0.979, 0.964, 0.956 and 0.972, respectively, and the root mean square error of prediction (RMSEP) of 6.587, 9.046, 9.998 and 7.751 μg/kg, respectively. The co-precipitation procedure combined with Raman spectroscopy method are feasible to detect the amount of heavy metals in water.

Yttrium oxide–magnesium oxide (Y₂O₃–MgO) composite nanopowders were synthesized via three distinct methods: sol–gel, co-precipitation and glycine–nitrate process. The synthesized powders were calcined at various temperatures, and their microstructure, specific surface area and particle size were characterized. A comparative study was conducted to assess the impact of the synthesis method on the microstructure and transparency of the resulting ceramic sintering. Notably, the powder synthesized by the sol–gel technique exhibited the highest specific surface area and superior light transmittance, reaching a maximum of 85.33% at a wavelength of 5.31$\mu$m.

Cobalt-Molybdenum alloy nanopowder has magnetic properties and is used as catalyst for production of carbon nanotubes. Properties of this nanopowder depend on, for example, its size, morphology and internal residual stress. Synthesis of nanopowder of Molybdenum-Cobalt alloy by co-precipitation in an aqueous media using NH₄OH as precipitating agent followed by calcination and reduction was investigated. The synthesis was started by dissolving salts of Cobalt and Molybdenum in water. A suspension of alumina or silica powders was used as a bed for precipitation. The effect of bed materials on size and morphology of the precipitate was investigated. The particles observed with scanning electron microscope possess a spherical shape and a needle shape for the samples participated on alumina and silica beds, respectively. XRD analysis of the calcined precipitate showed the formation of mixed oxide of CoMoO₄ as well as single oxides of Co₃O₄ and MoO₃. Particle size of the precipitate observed with transmission electron microscope was about 100 nm. Finally, the powders were reduced by hydrogen gas in a tubular furnace to prepare metallic nanopowder with composition of Co₃Mo.

A series of Nano MgAl_2-2xY_2xO₄ (x = 0.00, 0.07 & 0.10) was prepared by chemical co-precipitation technique. X-ray diffraction (XRD) analysis reveals that a secondary phase appears at x = 0.10 along with the spinel phase. The broad peaks in the XRD pattern and particle size analysis by Transmission electron microscopy (TEM) confirmed nanocrystalline nature of the samples. Room temperature dielectric response as a function of frequency (1 kHz to 1MHz) shows that dielectric constant loss tangent and ac conductivity decreases with increase in yttrium content. The variation of dielectric constant as a function of frequency indicates the dielectric dispersion due to Maxwell-Wagner Polarization. The variation of AC conductivity with frequency suggests the conduction mechanism due to small polaron hopping.