Ferromagnetic Sorbents Based on Nickel Nanowires for Efficient Uptake of Mercury from Water

• Published in: ACS applied materials & interfaces 2014-06, Vol.6 (11), p.8274-8280
• Main Authors: Pinheiro, Paula C, Tavares, Daniela S, Daniel-da-Silva, Ana L, Lopes, Cláudia B, Pereira, Eduarda, Araújo, João P, Sousa, Célia T, Trindade, Tito
• Format: Article
• Language: English
• ISSN: 1944-8244; 1944-8252
• DOI: 10.1021/am5010865

This work reports the preparation of ferro-magnetic nickel nanowires (NiNW) coated with dithiocarbamate-functionalized siliceous shells and its application for the uptake of aqueous Hg­(II) ions by magnetic separation. NiNW with an average diameter and length of 35 nm and 5 μm, respectively, were firstly prepared by Ni electrodeposition in an anodic aluminum oxide template. The NiNW surfaces were then coated with siliceous shells containing dithiocarbamate groups via a one-step procedure consisting in the alkaline hydrolytic co-condensation of tetraethoxysilane (TEOS) and a siloxydithiocarbamate precursor (SiDTC). A small amount of these new nanoadsorbents (2.5 mg·L–1) removed 99.8% of mercury ions from aqueous solutions with concentration 50 μg·L–1 and in less than 24 h of contact time. This outstanding removal ability is attributed to the high affinity of the sulfur donor ligands to Hg­(II) species combined with the high surface area-to-volume ratio of the NiNW.