کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
190170 | 459693 | 2011 | 6 صفحه PDF | دانلود رایگان |

Substitution of a metal center of phosphomolybdate, PMo12O403− (PMo12), or its tungsten analogue with dirhodium(II) and subsequent stabilization of gold nanoparticles, AuNPs, with Rh2PMo11 are demonstrated. The AuNP-Rh2PMo11 mediates oxidations but adsorbs too weakly for direct modification of electrode materials. Stability in quiescent solution was achieved by modifying glassy carbon (GC) with 3-aminopropyltriethoxysilane (APTES) and then electrostatically assembling AuNP-Rh2PMo11. At GC|APTES|AuNP-Rh2PMo11, cyclic voltammetry showed the expected set of three reversible peak-pairs for PMo11 in the range −0.2 to 0.6 vs. (Ag/AgCl)/V and the reversible RhII,III couple at 1.0 vs. (Ag/AgCl)/V. The presence of AuNPs increased the current for the reduction of bromate by a factor of 2.5 relative to that at GC|Rh2PMo11, and the electrocatalytic oxidation of methionine displayed characteristics of synergism between the AuNP and RhII. To stabilize AuNP-Rh2PMo11 on a surface in a flow system, GC was modified by electrochemically assisted deposition of a sol–gel with templated 10-nm pores prior to immobilizing the catalyst in the pores. The resulting electrode permitted determination of bromate by flow-injection amperometry with a detection limit of 4.0 × 10−8 mol dm−3.
Journal: Electrochimica Acta - Volume 56, Issue 10, 1 April 2011, Pages 3537–3542