Download Nanoscale zero-valent iron–Characterization and analytical

25th Croatian meeting of chemists and chemical engineers, Poreč, 2017.
Nanoscale zero-valent iron – Characterization and analytical application
Neutralno željezo na nanoskali - Karakterizacija i analitička primjena
Ivan Nemet1, Sanda Rončević1
1
Department of Chemistry,Faculty of Science, University of Zagreb, Zagreb, Croatia
E-mail: [email protected]
Nanomaterials have gained the greatest interest over other materials as the adsorbents of
analytes such as transition metals and semimetals from complex environmental samples. [1]
Utilization of zero-valent iron nanoparticles (nZVI) is widely adopted in analytical
preconcentration and extraction procedures due to large surface area, chemical stability,
durability, corrosion resistance, and cost effectiveness. Reductive immobilization of trace
quantities of potentiallly toxic metal species on iron nanoparticles is in focus of many studies
directed toward environmental and health effects. Removal efficiency is often determined by
imaging of solid particles by scanning emission microscopy, or by X-ray diffraction. The studies
which concern the changes of solution, especially aqueous solution are rarely described in
literature. [2] Therefore, in this work we have developed the ICP-OES method for quantitative
analysis of chromium (VI) removal from water by nanoscale iron.
Zero valent iron nanoparticles (nZVI) were synthesized in ethanolic medium by the method of
ferric iron reduction using sodium borohydride as a reducing agent. A systematic
characterization of nZVI was performed using XRD and SEM studies. The extraction capabilities
of synthesized particles were tested and optimized to mass fraction used in the experiments
on model aqueous solutions containing hexavalent chromium species. The efficiency of Cr(VI)
removal from aqueous solutions was measured by ICP-OES analysis on selected chromium
emission lines. Reductive immobilization of hexavalent chromium on bare nanoparticles and
nanoparticles which were modified by addition of 1,5-diphenylcarbazide was performed. [3]
Separation of particles from solution was achieved using solid phase extraction (SPE). The
sensitive plasma spectrometry measurements of starting and residual chromium content
showed that better removal efficiency (96 %) was obtained in lower concentration range (1-5
mg L-1) of Cr(VI) and with the addition of 1,5-diphenylcarbazide reagent.
References:
[1] X. Jiang, K. Huang, D. Deng, H. Xia, X. Hou, and C. Zheng, Trends Anal. Chem. 39 (2012) 38-59.
[2] P. Huang, Z. Ye, W. Xie, Q. Chen, J. Li, Z. Xu, M. Yao, Water Res. 47 (2013) 4050-4058.
[3] Z. Fang, X. Qui, R. Huang, X.Qiu, M.Li, Desalination 280 (2011) 224-231