近年來奈米零價鐵在環境復育領域被廣泛的應用。此零價金屬具有低毒性、豐富性以及適當的電位可用來進行化學還原反應。然而奈米零價鐵的鐵磁性容易引起顆粒的嚴重聚集，使其移動性和反應性降低。近年來利用固態載體修飾奈米零價鐵為常見的技術之一，目的是為了要改善其反應活性。本篇研究將亞鐵離子吸附在氧化石墨烯上，之後用硼氫化鈉直接將材料還原成零價鐵複合還原石墨烯(rGO-Fe)。利用調控鐵前驅物和氧化石墨烯的重量比例，就能合成出均勻分散的奈米零價鐵。本研究的奈米零價鐵其顆粒尺寸為44.1nm，在三氯乙烯的降解反應下，其擬一階反應動力常數(kobs)為9.40×10-3 h-1, 比未經修飾的零價鐵高出3倍。因為雙金屬系統具有協同效應現象，所以加入共同金屬離子可以大大的提升零價鐵的反應活性。添加1.877 mM的金屬鎳離子和0.105 mM的金屬鈀離子於反應系統中，其三氯乙烯降解擬一階反應速率常數為分別為5.89和 53.6 h-1 ，皆大於單純的rGO-Fe奈米複合材料( 9.40×10-3 h-1)。此結果證實rGO-Fe複合材料在污染物水處理的效果的確優異。它的高反應活性和大的比表面積使之在環境領域運用上頗具潛力，並值得開發成多功能材料。

Nanoscale zerovalent iron (nZVI) has been widely used in environmental remediation. It has low toxicity, abundance in the world, suitable potential for triggering the reduction make it a promising material in decades. However, the ferromagnetism of ZVI nanoparticles leads to aggregation, causing low reactivity and mobility. In recent years, using solid supports for nZVI is one of the methods enhancing its reactivity. In this study, a facile approach for the synthesis and immobilization of ZVI nanoparticles onto reduced graphene oxide (rGO) have developing by adding NaBH4 as reducing agent. By adjusting the weight ratio between iron precursors and graphene oxide, we can purchase the well-dispersed ZVI nanoparticles on reduced graphene oxide. In this study, the diameter of particles of rGO-Fe nanocomposites was about 44.1 nm. Its pseudo-first rate constant (kobs) of TCE degradation can reach to 9.40×10-3 h-1, which was 3 times higher than conventional ZVI. Due to synergetic effect, adding second metal ions can significantly enhanced the reactivity of rGO-Fe nanocomposites. The kobs for TCE degradation were 5.89, and 53.6 h-1 at 1.877 mM Ni(II), 0.105 mM Pd(II). Both of them are much higher than rGO-Fe nanocomposites alone ( 9.40×10-3 h-1). The result obtained in this study proving that immobilization of ZVI nanoparticles on reduced graphene oxide is successful in water treatment. Its high reactivity and large surface area make it have potential developing in multifunctional use in environmental application.

1. Pagga, U.; Brown, D., The degradation of dyestuffs. 2. Behavior of dyestuffs in aerobic biodegradation tests. Chemosphere 1986, 15, (4), 479-491.
2. Legrini, O.; Oliveros, E.; Braun, A. M., Photochemical processes for water-treatment. Chem. Rev. 1993, 93, (2), 671-698.
3. Wang, J. M.; Huang, C. P.; Allen, H. E.; Cha, D. K.; Kim, D. W., Adsorption characteristics of dye onto sludge particulates. Journal of Colloid and Interface Science 1998, 208, (2), 518-528.
4. Ai, L. H.; Zhang, C. Y.; Chen, Z. L., Removal of methylene blue from aqueous solution by a solvothermal-synthesized graphene/magnetite composite. J. Hazard. Mater. 2011, 192, (3), 1515-1524.
5. Scherer, M. M.; Richter, S.; Valentine, R. L.; Alvarez, P. J. J., Chemistry and microbiology of permeable reactive barriers for in situ groundwater clean up. Crit. Rev. Environ. Sci. Technol. 2000, 30, (3), 363-411.
6. US Environmental Protection Agency, Edition of Drinking Water Standards and Health Advisories; EPA 822-R-09-011, EPA Office of Water, Washington, DC, 2009.
7. Zhang, W. X., Nanoscale iron particles for environmental remediation: An overview. J. Nanopart. Res. 2003, 5, (3-4), 323-332.
8. Fu, F. L.; Dionysiou, D. D.; Liu, H., The use of zero-valent iron for groundwater remediation and wastewater treatment: A review. J. Hazard. Mater. 2014, 267, 194-205.
9. Bleyl, S.; Kopinke, F. D.; Mackenzie, K., Carbo-Iron (R)-Synthesis and stabilization of Fe(0)-doped colloidal activated carbon for in situ groundwater treatment. Chem. Eng. J. 2012, 191, 588-595.
10. Qiu, X. H.; Fang, Z. Q.; Liang, B.; Gu, F. L.; Xu, Z. C., Degradation of decabromodiphenyl ether by nano zero-valent iron immobilized in mesoporous silica microspheres. J. Hazard. Mater. 2011, 193, 70-81.
11. Jia, H. Z.; Wang, C. Y., Adsorption and dechlorination of 2,4-dichlorophenol (2,4-DCP) on a multi-functional organo-smectite templated zero-valent iron composite. Chem. Eng. J. 2012, 191, 202-209.
12. Wang, Y. Q.; Liu, W.; Wang, T.; Ni, J. R., Arsenate adsorption onto Fe-TNTs prepared by a novel water-ethanol hydrothermal method: Mechanism and synergistic effect. Journal of Colloid and Interface Science 2015, 440, 253-262.
13. Wu, Z. S.; Zhou, G. M.; Yin, L. C.; Ren, W.; Li, F.; Cheng, H. M., Graphene/metal oxide composite electrode materials for energy storage. Nano Energy 2012, 1, (1), 107-131.
14. Yao, Y. J.; Miao, S. D.; Liu, S. Z.; Ma, L. P.; Sun, H. Q.; Wang, S. B., Synthesis, characterization, and adsorption properties of magnetic Fe3O4@graphene nanocomposite. Chem. Eng. J. 2012, 184, 326-332.
15. Wang, H.; Yuan, X. Z.; Wu, Y.; Chen, X. H.; Leng, L. J.; Wang, H.; Li, H.; Zeng, G. M., Facile synthesis of polypyrrole decorated reduced graphene oxide-Fe3O4 magnetic composites and its application for the Cr(VI) removal. Chem. Eng. J. 2015, 262, 597-606.
16. Liu, Y.; Luo, C.; Cui, G. J.; Yan, S. Q., Synthesis of manganese dioxide/iron oxide/graphene oxide magnetic nanocomposites for hexavalent chromium removal. RSC Adv. 2015, 5, (67), 54156-54164.
17. Arnold, W. A.; Roberts, A. L., Pathways and kinetics of chlorinated ethylene and chlorinated acetylene reaction with Fe(O) particles. Environ. Sci. Technol. 2000, 34, (9), 1794-1805.
18. He, F.; Zhao, D. Y., Preparation and characterization of a new class of starch-stabilized bimetallic nanoparticles for degradation of chlorinated hydrocarbons in water. Environ. Sci. Technol. 2005, 39, (9), 3314-3320.
19. Zhuang, Y.; Ahn, S.; Seyfferth, A. L.; Masue-Slowey, Y.; Fendorf, S.; Luthy, R. G., Dehalogenation of Polybrominated Diphenyl Ethers and Polychlorinated Biphenyl by Bimetallic, Impregnated, and Nanoscale Zerovalent Iron. Environ. Sci. Technol. 2011, 45, (11), 4896-4903.
20. Tseng, H. H.; Su, J. G.; Liang, C. J., Synthesis of granular activated carbon/zero valent iron composites for simultaneous adsorption/dechlorination of trichloroethylene. J. Hazard. Mater. 2011, 192, (2), 500-506.
21. Yin, W. Z.; Wu, J. H.; Li, P.; Wang, X. D.; Zhu, N. W.; Wu, P. X.; Yang, B., Experimental study of zero-valent iron induced nitrobenzene reduction in groundwater: The effects of pH, iron dosage, oxygen and common dissolved anions. Chem. Eng. J. 2012, 184, 198-204.
22. Zhang, W.; Chen, L.; Chen, H.; Xia, S. Q., The effect of Fe-0/Fe2+/Fe3+ on nitrobenzene degradation in the anaerobic sludge. J. Hazard. Mater. 2007, 143, (1-2), 57-64.
23. Mangal, H.; Saxena, A.; Rawat, A. S.; Kumar, V.; Rai, P. K.; Datta, M., Adsorption of nitrobenzene on zero valent iron loaded metal oxide nanoparticles under static conditions. Microporous Mesoporous Mat. 2013, 168, 247-256.
24. Hu, S. H.; Yao, H. R.; Wang, K. F.; Lu, C.; Wu, Y. G., Intensify Removal of Nitrobenzene from Aqueous Solution Using Nano-Zero Valent Iron/Granular Activated Carbon Composite as Fenton-Like Catalyst. Water Air Soil Pollut. 2015, 226, (5), 13.
25. Shi, L. N.; Zhang, X.; Chen, Z. L., Removal of Chromium (VI) from wastewater using bentonite-supported nanoscale zero-valent iron. Water Research 2011, 45, (2), 886-892.
26. Melitas, N.; Chuffe-Moscoso, O.; Farrell, J., Kinetics of soluble chromium removal from contaminated water by zerovalent iron media: Corrosion inhibition and passive oxide effects. Environ. Sci. Technol. 2001, 35, (19), 3948-3953.
27. Budiman, F.; Bashirom, N.; Tan, W. K.; Razak, K. A.; Matsuda, A.; Lockman, Z., Rapid nanosheets and nanowires formation by thermal oxidation of iron in water vapour and their applications as Cr(VI) adsorbent. Appl. Surf. Sci. 2016, 380, 172-177.
28. Ge, X.; Liu, J. T.; Song, X. Y.; Wang, G. Z.; Zhang, H. M.; Zhang, Y. X.; Zhao, H. J., Hierarchical iron containing gamma-MnO2 hollow microspheres: A facile one-step synthesis and effective removal of As(III) via oxidation and adsorption. Chem. Eng. J. 2016, 301, 139-148.
29. Su, C. M.; Puls, R. W., Arsenate and arsenite removal by zerovalent iron: Effects of phosphate, silicate, carbonate, borate, sulfate, chromate, molybdate, and nitrate, relative to chloride. Environ. Sci. Technol. 2001, 35, (22), 4562-4568.
30. Khalil, A. M. E.; Eljamal, O.; Jribi, S.; Matsunaga, N., Promoting nitrate reduction kinetics by nanoscale zero valent iron in water via copper salt addition. Chem. Eng. J. 2016, 287, 367-380.
31. Shi, J. L.; Long, C.; Li, A. M., Selective reduction of nitrate into nitrogen using Fe-Pd bimetallic nanoparticle supported on chelating resin at near-neutral pH. Chem. Eng. J. 2016, 286, 408-415.
32. Ramirez, J. H.; Maldonado-Hodar, F. J.; Perez-Cadenas, A. F.; Moreno-Castilla, C.; Costa, C. A.; Madeira, L. M., Azo-dye Orange II degradation by heterogeneous Fenton-like reaction using carbon-Fe catalysts. Appl. Catal. B-Environ. 2007, 75, (3-4), 312-323.
33. Wang, Y. X.; Sun, H. Q.; Duan, X. G.; Ang, H. M.; Tade, M. O.; Wang, S. B., A new magnetic nano zero-valent iron encapsulated in carbon spheres for oxidative degradation of phenol. Appl. Catal. B-Environ. 2015, 172, 73-81.
34. MH Jang, M Lim, YS Hwang, Potential environmental implications of nanoscale zero-valent iron particles for environmental remediation. Environmental Health and Toxicology 2014, 29, 1-9.
35. Matheson, L. J.; Tratnyek, P. G., Reductive dehalogenation of chlorinated methanes by iron metal. Environ. Sci. Technol. 1994, 28, (12), 2045-2053.
36. Glavee, G. N.; Klabunde, K. J.; Sorensen, C. M.; Hadjipanayis, G. C., Chemistry of borohydride reduction of iron(II) and iron(III) ions in aqueous and nonaqueous media-formation of nannoscale Fe, FeB and Fe2B powders. Inorg. Chem. 1995, 34, (1), 28-35.
37. Wang, C. B.; Zhang, W. X., Synthesizing nanoscale iron particles for rapid and complete dechlorination of TCE and PCBs. Environ. Sci. Technol. 1997, 31, (7), 2154-2156.
38. Tee, Y. H.; Bachas, L.; Bhattacharyya, D., Degradation of Trichloroethylene and Dichlorobiphenyls by Iron-Based Bimetallic Nanoparticles. J. Phys. Chem. C 2009, 113, (22), 9454-9464.
39. Barnes, R. J.; Riba, O.; Gardner, M. N.; Scott, T. B.; Jackman, S. A.; Thompson, I. P., Optimization of nano-scale nickel/iron particles for the reduction of high concentration chlorinated aliphatic hydrocarbon solutions. Chemosphere 2010, 79, (4), 448-454.
40. Schrick, B.; Blough, J. L.; Jones, A. D.; Mallouk, T. E., Hydrodechlorination of trichloroethylene to hydrocarbons using bimetallic nickel-iron nanoparticles. Chem. Mat. 2002, 14, (12), 5140-5147.
41. Zhou, J. S.; Song, H. H.; Ma, L. L.; Chen, X. H., Magnetite/graphene nanosheet composites: interfacial interaction and its impact on the durable high-rate performance in lithium-ion batteries. RSC Adv. 2011, 1, (5), 782-791.
42. Elliott, D. W.; Zhang, W. X., Field assessment of nanoscale biometallic particles for groundwater treatment. Environ. Sci. Technol. 2001, 35, (24), 4922-4926.
43. Lien, H. L.; Zhang, W. X., Nanoscale Pd/Fe bimetallic particles: Catalytic effects of palladium on hydrodechlorination. Appl. Catal. B-Environ. 2007, 77, (1-2), 110-116.
44. Zhang, W. X.; Wang, C. B.; Lien, H. L., Treatment of chlorinated organic contaminants with nanoscale bimetallic particles. Catal. Today 1998, 40, (4), 387-395.
45. Lai, B.; Zhang, Y. H.; Chen, Z. Y.; Yang, P.; Zhou, Y. X.; Wang, J. L., Removal of p-nitrophenol (PNP) in aqueous solution by the micron-scale iron-copper (Fe/Cu) bimetallic particles. Appl. Catal. B-Environ. 2014, 144, 816-830.
46. Yan, W. L.; Herzing, A. A.; Li, X. Q.; Kiely, C. J.; Zhang, W. X., Structural Evolution of Pd-Doped Nanoscale Zero-Valent Iron (nZVI) in Aqueous Media and Implications for Particle Aging and Reactivity. Environ. Sci. Technol. 2010, 44, (11), 4288-4294.
47. Huang, Q.; Liu, W.; Peng, P. A.; Huang, W. L., Reductive dechlorination of tetrachlorobisphenol A by Pd/Fe bimetallic catalysts. J. Hazard. Mater. 2013, 262, 634-641.
48. Nie, X. Q.; Liu, J. G.; Zeng, X. W.; Yue, D. B., Rapid degradation of hexachlorobenzene by micron Ag/Fe bimetal particles. Journal of environmental sciences 2013, 25, (3), 473-478.
49. Xu, F. Y.; Deng, S. B.; Xu, J.; Zhang, W.; Wu, M.; Wang, B.; Huang, J.; Yu, G., Highly Active and Stable Ni-Fe Bimetal Prepared by Ball Milling for Catalytic Hydrodechlorination of 4-Chlorophenol. Environ. Sci. Technol. 2012, 46, (8), 4576-4582.
50. Cao, J.; Xu, R. F.; Tang, H.; Tang, S. S.; Cao, M. H., Synthesis of monodispersed CMC-stabilized Fe-Cu bimetal nanoparticles for in situ reductive dechlorination of 1, 2, 4-trichlorobenzene. Sci. Total Environ. 2011, 409, (11), 2336-2341.
51. Koutsospyros, A.; Pavlov, J.; Fawcett, J.; Strickland, D.; Smolinski, B.; Braida, W., Degradation of high energetic and insensitive munitions compounds by Fe/Cu bimetal reduction. J. Hazard. Mater. 2012, 219, 75-81.
52. Zhang, R.; Li, J.; Liu, C.; Shen, J.; Sun, X.; Han, W.; Wang, L., Reduction of nitrobenzene using nanoscale zero-valent iron confined in channels of ordered mesoporous silica. Colloid Surf. A-Physicochem. Eng. Asp. 2013, 425, 108-114.
53. Ling, X. F.; Li, J. S.; Zhu, W.; Zhu, Y. Y.; Sun, X. Y.; Shen, J. Y.; Han, W. Q.; Wang, L. J., Synthesis of nanoscale zero-valent iron/ordered mesoporous carbon for adsorption and synergistic reduction of nitrobenzene. Chemosphere 2012, 87, (6), 655-660.
54. Zhu, H. J.; Jia, Y. F.; Wu, X.; Wang, H., Removal of arsenic from water by supported nano zero-valent iron on activated carbon. J. Hazard. Mater. 2009, 172, (2-3), 1591-1596.
55. Du, Q.; Zhang, S. J.; Pan, B. C.; Lv, L.; Zhang, W. M.; Zhang, Q. X., Bifunctional resin-ZVI composites for effective removal of arsenite through simultaneous adsorption and oxidation. Water Research 2013, 47, (16), 6064-6074.
56. Lv, X. S.; Xu, J.; Jiang, G. M.; Xu, X. H., Removal of chromium(VI) from wastewater by nanoscale zero-valent iron particles supported on multiwalled carbon nanotubes. Chemosphere 2011, 85, (7), 1204-1209.
57. Jabeen, H.; Chandra, V.; Jung, S.; Lee, J. W.; Kim, K. S.; Bin Kim, S., Enhanced Cr(VI) removal using iron nanoparticle decorated graphene. Nanoscale 2011, 3, (9), 3583-3585.
58. Sun, Z. Z.; James, D. K.; Tour, J. M., Graphene Chemistry: Synthesis and Manipulation. J. Phys. Chem. Lett. 2011, 2, (19), 2425-2432.
59. He, H. Y.; Klinowski, J.; Forster, M.; Lerf, A., A new structural model for graphite oxide. Chem. Phys. Lett. 1998, 287, (1-2), 53-56.
60. Chandra, V.; Park, J.; Chun, Y.; Lee, J. W.; Hwang, I. C.; Kim, K. S., Water-Dispersible Magnetite-Reduced Graphene Oxide Composites for Arsenic Removal. ACS Nano 2010, 4, (7), 3979-3986.
61. Zhu, J. H.; Wei, S. Y.; Gu, H. B.; Rapole, S. B.; Wang, Q.; Luo, Z. P.; Haldolaarachchige, N.; Young, D. P.; Guo, Z. H., One-Pot Synthesis of Magnetic Graphene Nanocomposites Decorated with Core@Double-shell Nanoparticles for Fast Chromium Removal. Environ. Sci. Technol. 2012, 46, (2), 977-985.
62. Kim, H.; Hong, H. J.; Jung, J. D. o. t. T. b. n. z.-v. i. n. i. i. a. b. K., S. H.; Yang, J. W., Degradation of trichloroethylene (TCE) by nanoscale zero-valent iron (nZVI) immobilized in alginate bead. J. Hazard. Mater. 2010, 176, (1-3), 1038-1043.
63. Tang, H.; Zhu, D. Q.; Li, T. L.; Kong, H. N.; Chen, W., Reductive Dechlorination of Activated Carbon-Adsorbed Trichloroethylene by Zero-Valent Iron: Carbon as Electron Shuttle. J. Environ. Qual. 2011, 40, (6), 1878-1885.
64. Sreeprasad, T. S.; Maliyekkal, S. M.; Lisha, K. P.; Pradeep, T., Reduced graphene oxide-metal/metal oxide composites: Facile synthesis and application in water purification. J. Hazard. Mater. 2011, 186, (1), 921-931.
65. Tesh, S. J.; Scott, T. B., Nano-Composites for Water Remediation: A Review. Adv. Mater. 2014, 26, (35), 6056-6068.
66. Wei, J. J.; Qian, Y. J.; Liu, W. J.; Wang, L. T.; Ge, Y. J.; Zhang, J. H.; Yu, J.; Ma, X. M., Effects of particle composition and environmental parameters on catalytic hydrodechlorination of trichloroethylene by nanoscale bimetallic Ni-Fe. Journal of environmental sciences 2014, 26, (5), 1162-1170.
67. Zhou, T.; Li, Y. Z.; Lim, T. T., Catalytic hydrodechlorination of chlorophenols by Pd/Fe nanoparticles: Comparisons with other bimetallic systems, kinetics and mechanism. Sep. Purif. Technol. 2010, 76, (2), 206-214.
68. Han, Y. L.; Liu, C. J.; Horita, J.; Yan, W. L., Trichloroethene hydrodechlorination by Pd-Fe bimetallic nanoparticles: Solute-induced catalyst deactivation analyzed by carbon isotope fractionation. Appl. Catal. B-Environ. 2016, 188, 77-86.
69. Min, S. D.; Zhao, C. J.; Chen, G. R.; Qian, X. Z., One-pot hydrothermal synthesis of reduced graphene oxide/Ni(OH)(2) films on nickel foam for high performance supercapacitors. Electrochim. Acta 2014, 115, 155-164.
70. Wang, D. W.; Min, Y. G.; Yu, Y. H.; Peng, B., A general approach for fabrication of nitrogen-doped graphene sheets and its application in supercapacitors. Journal of Colloid and Interface Science 2014, 417, 270-277.