Synthesis and shapes of gold nanoparticles by using transition metal monosubstituted heteropolyanions as photocatalysts and stabilizers

Abstract

Gold nanoparticles were prepared via a simple photoreduction technique in the presence of transition metal monosubstituted Keggin heteropolyanions (PW11M, M= Cu²⁺, Ni²⁺, Zn²⁺, Fe³⁺), in which PW11M acted as reducing agent, photocatalyst and stabilizer. The results indicated that the formation rate and morphology of the nanoparticles strongly depended on the kind of transition metal substituted in heteropolyacid and the preparation conditions, such as irradiation time and propan-2-ol amount. The photoreduction rates of PW11Zn and PW11Fe were faster than those of PW11Ni and PW11Cu. The shapes of the nanoparticles synthesized in the presence of PW11Fe and PW11Zn were nearly uniform spheres, whereas the morphologies of the nanoparticles synthesized in the presence of PW11Ni and PW11Cu were found to contain a mixture of flat triangular/hexagonal structures as well as spheres. Increases in the irradiation time and the propan-2-ol amount could make the morphology of nanoparticles uniform and shorten the formation time of the nanoparticles.

Keywords

heteropolyanion / photoreduction / gold nanoparticle

References

[1] Papaconstantinou E. Photochemistry of Polyoxometallates of Molybdenum and Tungsten and/or Vanadium. Chem Soc Rev, 1989, 18: 1–31

[2] Wang E B, Hu C W, Xu L. Introduction to polyacid chemistry. Beijing: Chemical Inductry Press, 1998, 87

[3] Toshihiro Yamase. Photo- and Electrochromism of Polyoxometalates and Related Materials. Chem Rev, 1998, 98(1): 307–325

[4] Weinstock I A. Homogeneous-Phase Electron-Transfer Reactions of Polyoxometalates. Chem Rev, 1998, 98(1): 113–170

[5] Troupis A, Hiskia A, Papaconstantinou E. Synthesis of Metal Nanoparticles by Using Polyoxometalates as Photocatalysts and Stabilizers. Angew Chem Int Ed, 2002, 41(11): 1911–1914

[6] Mandal S, Das A, Srivastava R, and Sastry M. Keggin Ion Mediated Synthesis of Hydrophobized Pd Nanoparticles for Multifunctional Catalysis. Langmuir, 2005, 21(6): 2408–2413

[7] Mandal S, Selvakannan P R, Pasricha R, Sastry M. Keggin Ions as UV-Switchable Reducing Agents in the Synthesis of Au Core-Ag Shell Nanoparticles. J Am Chem Soc, 2003, 125(28): 8440–8441

[8] Troupis A, Hiskia A, Papaconstantinou E. Photocatalytic Reduction and Recovery of Copper by Polyoxometalates. Environ Sci Technol, 2002, 36(24): 5355–5362

[9] Troupis A, Hiskia A, Papaconstantinou E. Selective photocatalytic reduction–recovery of palladium using polyoxometallates. Applied Catalysis B: Environmental, 2004, 52: 41–48

[10] He H M, Sun T, Jiang D Z. Study on Preparation and Characterization of Hydrotalcites Pillared with Tri-atomic Heteropoly Anions of P-W System.Chinese Journal of Inorganic Chemistry, 1994, 10(3): 272–277 (in Chinese)

[11] Shankar S S, Rai A, Ahmad A, Sastry M. Controlling the Optical Properties of Lemongrass Extract Synthesized Gold Nanotriangles and Potential Application in Infrared-Absorbing Optical Coatings. Chem Mater, 2005, 17(3): 566–572

[12] Rai A, Singh A, Ahmad A, Sastry M. Role of Halide Ions and Temperature on the Morphology of Biologically Synthesized Gold Nanotriangles. Langmuir, 2006, 22(2): 736–741

[13] Sarma T K and Chattopadhyay A. Starch-Mediated Shape-Selective Synthesis of Au Nanoparticles with Tunable Longitudinal Plasmon Resonance. Langmuir, 2004, 20(9): 3520–3524

RIGHTS & PERMISSIONS

Higher Education Press and Springer-Verlag Berlin Heidelberg