Direct Synthesis of Novel and Reactive Sulfide-modified Nano Iron through Nanoparticle Seeding for Improved Cadmium-Contaminated Water Treatment.
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.
State Key Laboratory of Pollution Control and Resources Reuse, Tongji University, Shanghai 200092, China.
Yiming
Y
Su
Bren School of Environmental Science &Management, University of California, Santa Barbara, 3420 Bren Hall, CA 93106, USA.|University of California Center for Environmental Implications of Nanotechnology, Santa Barbara, California, USA.
Adeyemi S
AS
Adeleye
Bren School of Environmental Science &Management, University of California, Santa Barbara, 3420 Bren Hall, CA 93106, USA.
Yuxiong
Y
Huang
State Key Laboratory of Pollution Control and Resources Reuse, Tongji University, Shanghai 200092, China.
Xuefei
X
Zhou
Bren School of Environmental Science &Management, University of California, Santa Barbara, 3420 Bren Hall, CA 93106, USA.|University of California Center for Environmental Implications of Nanotechnology, Santa Barbara, California, USA.
Arturo A
AA
Keller
State Key Laboratory of Pollution Control and Resources Reuse, Tongji University, Shanghai 200092, China.|Key Laboratory of Yangtze Water Environment for Ministry of Education, Tongji University, Shanghai 200092, China.
Yalei
Y
Zhang