The study of detecting hexavalent chromium by gold nanoparticle modified electrodes and electrodeposition of macroporous silver films in room-temperature ionic liquids

• Main Authors: Ming-Chih Tsai, 蔡明志
• Other Authors: Po-Yu Chen
• Format: Others
• Language: zh-TW
• Published: 2009
• Online Access: http://ndltd.ncl.edu.tw/handle/79345669491831503813

碩士 === 高雄醫學大學 === 醫藥暨應用化學研究所 === 97 === This study reports the voltammetric behavior of hexavalent chromium species (Cr (VI)) at ITO, bulk Au, and indium tin oxide electrode modified with gold nanoparticls (AuNP/ITO) in acidic aqueous solutions and the electrodeposition of macroporous silver films in the ionic liquids BMP-TFSI (N-butyl-N-methylpyrrolidiniumbis((trifluoromethyl)sulfonyl) imide) and BMP-DCA (N-butyl-N-methylpyrrolidinium dicyanamide) using polystyrene latex as the template. All the electrodepositing samples were analyzed with a scanning electron microscope (SEM). AuNP/ITO was fabricated by potential-sweeping or potential-step electrodeposition in 0.01 M Na2SO4 solution containing 0.01 M H2SO4 plus 1 mM HAuCl4∙3H2O. SEM images of AuNP/ITO show that Au nanoparticls were distributed uniformly. Cr (VI) was determined by cyclic voltammetry (CV) or hydrodynamic amperometry (HA). AuNP/ITO is more sensitive and stable than ITO electrodes in determination of Cr(VI). By CV, the dependence of Cr(VI) reduction current versus concentration was linear from 5×10-6 M to 1×10-4 M with a regression coefficient of 0.997. By HA, it was linear from 5×10-7 M to 5×10-5 M with a regression coefficient of 0.999. Electrodeposition of ordered macroporous silver films in BMP-TFSI and BMP-DCA using polystyrene latex as the template. Ordered macroporous Ag film shows a color change when the angle of incident white light is changed. The resulting macroporous Ag film possesses high surface area and electrochemical activity to nitrate detection. Our method provides an easy and convenient way to prepare ordered macroporous structures.