resumo
This work reports the preparation of ferromagnetic 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 mu m, 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 siloxydithio-carbamate 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 mu g.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.
palavras-chave
MAGNETIC NANOWIRES; REMOVAL; PARTICLES; NANOPARTICLES; NANOMATERIALS; REMEDIATION; ALUMINA; ARRAYS
categoria
Science & Technology - Other Topics; Materials Science
autores
Pinheiro, PC; Tavares, DS; Daniel-da-Silva, AL; Lopes, CB; Pereira, E; Araujo, JP; Sousa, CT; Trindade, T
nossos autores
Ana Luísa Daniel da Silva
Investigador Principal
Cláudia Batista Lopes
Investigador Auxiliar
Daniela Soraia dos Santos Tavares
Estudante de doutoramento
Paula Pinheiro
Bolseiro de investigação
Tito Trindade
Professor CatedráticoProjectos
agradecimentos
This work was financed by national funding from FCT (Fundacao para a Ciencia e a Tecnologia) through the project PTDC/CTM-NAN/120668/2010, by FEDER through program COMPETE, and through FCT/FEDER in the frame of projects Pest-C/CTM/LA0011/2013 and Pest-C/MAR/LA0017/2013. P. C. Pinheiro thanks FCT for the grant SFRH/BD/96731/2013. C. T. Sousa thanks FCT for the grant SFRH/BPD/82010/2011. We thank the RNME (National Electronic Microscopy Network) for microscopy facilities.