Synthesis of Cu/CuO hydrides for enhanced removal of iodide from water.

In order to improve the removal capacity of CuO for I anions from water, Cu/CuO hybrids have been synthesized through a facile hydrothermal route, characterized by using SEM, XRD, XPS, and applied to remove I anions under different experimental environments. The results demonstrate that the Cu content and morphology of samples can be tuned by the adding amount of ammonia. Meanwhile, the possible crystalline mechanism, CuO formed firstly and then metallic Cu generated, was presented. With the increasing of Cu doped amount, the removal capacity of Cu/CuO hybrids increased significantly from 0.02mmolg to 0.18mmolg. Furthermore, a reaction mechanism of I anions and CuO, which generated from the disproportionation reaction of metallic Cu and CuO, has been proposed according to the characterization analyses of the composites before and after adsorption, explaining the highly efficient removal of I anions. In addition, Cu/CuO hybrids showed excellent selectivity for I anions in the presence of large concentrations of competitive anions such as SO and NO and could work in an acidic and neutral environment. This study is hopefully to prompt CuO to grow up to be a new and highly efficient adsorbent for the removal of iodide from solutions.