The effect of the precipitation conditions on the morphology and the sorption properties of CuS particles

Resumo

The effect of the nature of the copper salt precursor anion and the pH of a solution on the morphology and the phase composition of CuS particles has been studied upon precipitation from thiourea solutions. It has been established that, irrespective of the precipitation conditions, generation of the CuS phase and the chalcanthite impurity phase CuSO₄ • 5H₂O is recorded according to the X-ray diffraction analysis data. At pH 8 and a c((NH₂)₂CS): c(Cu²⁺) ratio of 1: 1, from nitrate solutions a fine powder is formed that consists of spherical particles smaller than 100 nm in size. An increase in the c((NH₂)₂CS): c(Cu²⁺) ratio and in the precipitation pH results in coarser particles of up to 1.5 μm in size. The replacement of the salt precursor anion by SO₄^2- facilitates the decrease in the spherical particle size to 1 μm and that by Cl^– to 0.7 μm. The synthesis conditions of the CuS sorbent that control the latter’s morphological properties have an effect on the sorption of cadmium from aqueous solutions.