Air-stable nZVI formation mediated by glutamic acid: solid-state storable material exhibiting 2D chain morphology and high reactivity in aqueous environment
We report a new chemical approach toward air-stable nanoscale zero-valent iron (nZVI). The uniformly sized (approx. 80 nm) particles, formed by the reduction of Fe(II) salt by borohydride in the presence of glutamic acid, are coated by a thin inner shell of amorphous ferric oxide/hydroxide and a secondary shell consisting of glutamic acid. The as-prepared nanoparticles stabilized by the inorganic–organic double shell create 2D chain morphologies. They are storable for several months under ambient atmosphere without the loss of Fe(0) relative content. They show one order of magnitude higher rate constant for trichlorethene decomposition compared with the pristine particles possessing only the inorganic shell as a protective layer. This is the first example of the inorganic–organic (consisting of low-molecular weight species) double-shell stabilized nanoscale zero-valent iron material being safely transportable in solid-state, storable on long-term basis under ambient conditions, environmentally acceptable for in situ applications, and extraordinarily reactive if contacted with reducible pollutants, all in one.
KeywordsIron Nanoparticles TCE decomposition Moessbauer spectroscopy Magnetism
Dr. Dalibor Jančík is thanked for the analysis of SAED data, Bc. Jan Kolařík for AAS measurements, and Dr. Giorgio Zoppellaro for his valuable comments and encouragement. Financial support by P108/11/P657 Grant awarded by GACR, the project of the Ministry of Industry and Business of the Czech Republic (project ID: FR-TI3/196), the Operational Program Research and Development for Innovations - European Regional Development Fund (project CZ.1.05/2.1.00/03.0058 of the Ministry of Education, Youth and Sports of the Czech Republic), the projects of the Ministry of Education of the Czech Republic (1M6198959201 and MSM6198959218), and the project of the Academy of Sciences of the Czech Republic (KAN115600801) is gratefully acknowledged.
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