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Direct Synthesis of Novel and Reactive Sulfide-modified Nano Iron through Nanoparticle Seeding for Improved Cadmium-Contaminated Water Treatment.

Su Y, Adeleye AS, Huang Y, Zhou X, Keller AA, Zhang Y - Sci Rep (2016)

Bottom Line: Syntheses monitoring experiments show that seeding accelerates the reduction rate from Fe(2+) to Fe(0) by 19%.Both X-ray diffraction and Mössbauer analyses further confirm that increased nanoparticle seeding results in formation of more Fe(0) crystals.The synthesized nanohybrid has high cadmium removal capacity and holds promising prospects for treatment of metal-contaminated water.

View Article: PubMed Central - PubMed

Affiliation: State Key Laboratory of Pollution Control and Resources Reuse, Tongji University, Shanghai 200092, China.

ABSTRACT
Magnetic sulfide-modified nanoscale zerovalent iron (S-nZVI) is of great technical and scientific interest because of its promising application in groundwater remediation, although its synthesis is still a challenge. We develop a new nanoparticle seeding method to obtain a novel and reactive nanohybrid, which contains an Fe(0) core covered by a highly sulfidized layer under high extent of sulfidation. Syntheses monitoring experiments show that seeding accelerates the reduction rate from Fe(2+) to Fe(0) by 19%. X-ray adsorption near edge structure (XANES) spectroscopy and extended X-ray absorption fine structure analyses demonstrate the hexahedral Fe-Fe bond (2.45 and 2.83 Å) formation through breaking down of the 1.99 Å Fe-O bond both in crystalline and amorphous iron oxide. The XANES analysis also shows 24.2% (wt%) of FeS with bond length of 2.4 Å in final nanohybrid. Both X-ray diffraction and Mössbauer analyses further confirm that increased nanoparticle seeding results in formation of more Fe(0) crystals. Nano-SiO2 seeding brings down the size of single Fe(0) grain from 32.4 nm to 18.7 nm, enhances final Fe(0) content from 5.9% to 55.6%, and increases magnetization from 4.7 to 65.5 emu/g. The synthesized nanohybrid has high cadmium removal capacity and holds promising prospects for treatment of metal-contaminated water.

No MeSH data available.


Related in: MedlinePlus

Fe K-edge XANES liner combination fit for nanoparticles collected during synthesis: middle stage (A) and final stage (B) during nZVI synthesis process; middle stage (C) and final stage (D) during FeSSi synthesis process (- -, data; , fit; , residual; , Fe(0); , FeO; , gamma Fe2O3; , Fe3(PO4)2; , Hematite; , FeS; , FeSO4;). (Fe3(PO4)2 was used to represent the disordered Fe-O bond).
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f3: Fe K-edge XANES liner combination fit for nanoparticles collected during synthesis: middle stage (A) and final stage (B) during nZVI synthesis process; middle stage (C) and final stage (D) during FeSSi synthesis process (- -, data; , fit; , residual; , Fe(0); , FeO; , gamma Fe2O3; , Fe3(PO4)2; , Hematite; , FeS; , FeSO4;). (Fe3(PO4)2 was used to represent the disordered Fe-O bond).

Mentions: To further investigate the reduction pathway of FeSSi, XANES was employed to analyze the composition of nanomaterials collected at different time intervals from nZVI (Fig. 3a,b) and FeSSi (Fig. 3c,d) synthesis systems. A seen from Fig. 3a,b, collected at middle and final synthesis stages, respectively, the main composition of the particles at both stages is zerovalent iron. This indicates the continuous Fe0 nucleation from Fe2+ in solution (to form nanoparticles). However, in FeSSi synthesis system, instead of Fe0, abundance of iron oxide, both crystalline and amorphous, was initially observed. Then, iron oxide was then reduced to Fe0. Meanwhile, FeS was also formed. Liner combination fitting result shows 55.6% and 24.2% of Fe0 and FeS, respectively, in final nanohybrid (Table S1), both of which are important for pollutants removal.


Direct Synthesis of Novel and Reactive Sulfide-modified Nano Iron through Nanoparticle Seeding for Improved Cadmium-Contaminated Water Treatment.

Su Y, Adeleye AS, Huang Y, Zhou X, Keller AA, Zhang Y - Sci Rep (2016)

Fe K-edge XANES liner combination fit for nanoparticles collected during synthesis: middle stage (A) and final stage (B) during nZVI synthesis process; middle stage (C) and final stage (D) during FeSSi synthesis process (- -, data; , fit; , residual; , Fe(0); , FeO; , gamma Fe2O3; , Fe3(PO4)2; , Hematite; , FeS; , FeSO4;). (Fe3(PO4)2 was used to represent the disordered Fe-O bond).
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4837343&req=5

f3: Fe K-edge XANES liner combination fit for nanoparticles collected during synthesis: middle stage (A) and final stage (B) during nZVI synthesis process; middle stage (C) and final stage (D) during FeSSi synthesis process (- -, data; , fit; , residual; , Fe(0); , FeO; , gamma Fe2O3; , Fe3(PO4)2; , Hematite; , FeS; , FeSO4;). (Fe3(PO4)2 was used to represent the disordered Fe-O bond).
Mentions: To further investigate the reduction pathway of FeSSi, XANES was employed to analyze the composition of nanomaterials collected at different time intervals from nZVI (Fig. 3a,b) and FeSSi (Fig. 3c,d) synthesis systems. A seen from Fig. 3a,b, collected at middle and final synthesis stages, respectively, the main composition of the particles at both stages is zerovalent iron. This indicates the continuous Fe0 nucleation from Fe2+ in solution (to form nanoparticles). However, in FeSSi synthesis system, instead of Fe0, abundance of iron oxide, both crystalline and amorphous, was initially observed. Then, iron oxide was then reduced to Fe0. Meanwhile, FeS was also formed. Liner combination fitting result shows 55.6% and 24.2% of Fe0 and FeS, respectively, in final nanohybrid (Table S1), both of which are important for pollutants removal.

Bottom Line: Syntheses monitoring experiments show that seeding accelerates the reduction rate from Fe(2+) to Fe(0) by 19%.Both X-ray diffraction and Mössbauer analyses further confirm that increased nanoparticle seeding results in formation of more Fe(0) crystals.The synthesized nanohybrid has high cadmium removal capacity and holds promising prospects for treatment of metal-contaminated water.

View Article: PubMed Central - PubMed

Affiliation: State Key Laboratory of Pollution Control and Resources Reuse, Tongji University, Shanghai 200092, China.

ABSTRACT
Magnetic sulfide-modified nanoscale zerovalent iron (S-nZVI) is of great technical and scientific interest because of its promising application in groundwater remediation, although its synthesis is still a challenge. We develop a new nanoparticle seeding method to obtain a novel and reactive nanohybrid, which contains an Fe(0) core covered by a highly sulfidized layer under high extent of sulfidation. Syntheses monitoring experiments show that seeding accelerates the reduction rate from Fe(2+) to Fe(0) by 19%. X-ray adsorption near edge structure (XANES) spectroscopy and extended X-ray absorption fine structure analyses demonstrate the hexahedral Fe-Fe bond (2.45 and 2.83 Å) formation through breaking down of the 1.99 Å Fe-O bond both in crystalline and amorphous iron oxide. The XANES analysis also shows 24.2% (wt%) of FeS with bond length of 2.4 Å in final nanohybrid. Both X-ray diffraction and Mössbauer analyses further confirm that increased nanoparticle seeding results in formation of more Fe(0) crystals. Nano-SiO2 seeding brings down the size of single Fe(0) grain from 32.4 nm to 18.7 nm, enhances final Fe(0) content from 5.9% to 55.6%, and increases magnetization from 4.7 to 65.5 emu/g. The synthesized nanohybrid has high cadmium removal capacity and holds promising prospects for treatment of metal-contaminated water.

No MeSH data available.


Related in: MedlinePlus