Synthesis and Electrochemical Fabrication of Metal Nanoparticles and Carbon Nanomaterials for Electrochemical Sensors and Oxygen Reduction reaction

• Main Authors: Duo-Han Zhao, 趙多涵
• Other Authors: Shen-Ming Chen
• Format: Others
• Language: zh-TW
• Published: 2016
• Online Access: http://ndltd.ncl.edu.tw/handle/c24py7

碩士 === 國立臺北科技大學 === 化學工程研究所 === 104 === The first part in this paper, we report a highly sensitive amperometric H2O2 sensor based on silver nanowires (AgNWs) modified screen printed carbon electrode. The AgNWs were synthesized using polyol method with little modification, where ethylene glycol, isopropyl alcohol and polyvinylpyrolidone were used as the reducing, dispersing and capping agents respectively. The synthesized AgNWs were characterized by scanning electron microscopy, UV-Vis spectroscopy and X-ray diffraction techniques. The average diameter and length of the synthesized AgNWs were found as 86 ± 5 and 385 nm, respectively. Under optimum conditions, the AgNWs modified electrode shows a stable amperometric response for H2O2 and was linear over the concentrations ranging from 0.3 to 704.8 µM. The non-enzymatic sensors showed a high sensitivity of 725.7 µAmM–1 cm–2 with a detection limit of 29 nM. The response time of the sensor was found as 2 s. Furthermore, the AgNWs modified electrode exhibited a good recovery of H2O2 (94.3%.) in the human blood serum samples. The second part in this paper, we report the electrochemical detection of dissolved oxygen in neutral media using graphene oxide-platinum nanoparticles (GO-PtNPs) composite modified glassy carbon electrode (GCE).The GO-PtNPs composite modified electrode was prepared by immersing the GO modified electrode in deoxygenated 0.5 mM K2PtCl6 with 0.5 M KNO3 solution by cyclic voltammetry. As prepared materials were characterized by scanning electron microscopy and elemental analysis. The GO-PtNPs composite modified electrode showed an excellent electrocatalytic activity towards the reduction of oxygen in pH 7.0 solution than that of PtNPs and GO modified electrodes. The GO-PtNPs composite modified electrode was further used for the detection of dissolved oxygen (DO) in water. The electrochemical results revealed that GO-PtNPs composite modified electrode has high precision and accuracy with the results obtained from the commercial oxygen analyzer for the detection of DO in water. An amperometric determination of nitrite in different water samples was evaluated using palladium nanoparticles (PdNPs) decorated functionalized multiwalled carbon nanotubes (f-MWCNT) modified glassy carbon electrode (GCE). The f-MWCNT/PdNPs composite modified electrode was prepared by electrodeposition of PdNPs on the surface of f-MWCNT modified electrode. The parameters such as effect of number of cycles of PdNPs deposition, drop coated amount of f-MWCNT and effect of pH were optimized and discussed in detail.As-prepared f-MWCNT/PdNPs composite modified electrode exhibits excellent electrocatalytic activity towards the oxidation of nitrite compared to MWCNT, f-MWCNT and PdNPs modified electrodes. Amperometric i-t method was used to determine nitrite and the response of the nitrite on modified electrode was linear over the concentration from 0.05 to 2887.6 µM. The response time of the sensor was estimated as 3 s with the detection limit of 22 nM. The fabricated f-MWCNT/PdNPs composite modified electrode shows its satisfactory practical ability in nitrite containing different water samples, which authenticate its potential ability for determination of nitrite.