Investigation on the Electrochemical Properties of Rare-Earth Metal Vanadates and their Carbon Composites to the Electrochemical Sensors

• Main Authors: Thangavelu Kokulnathan, Kokulnathan
• Other Authors: 陳生明 教授
• Format: Others
• Language: en_US
• Published: 2018
• Online Access: http://ndltd.ncl.edu.tw/handle/8767zb

博士 === 國立臺北科技大學 === 能源與光電材料專班 === 106 === Environmental pollutions are highlighted to be the major global problems in this century. The overdosage and improper discharge of the pharmaceutical drug are directly posed treat to living organisms. Moreover, it directly contaminates the subsurface of aquatic and terrestrial environments. Electrochemical sensor offers several advantages for monitoring these issues. Mainly, the electrochemical performance was based on the electrode material. The skyrocketing environmental pollution are motivated to explore novel electrode materials for electrochemical sensors with superior performance, cost-effective, and environmental-friendliness. This thesis mainly documented the synthesis of new electrode material for the detection of pharmaceutical drugs. Thereby, we focused on the rare earth vanadates and their nanocomposite for the electrochemical sensor. Mostly, the rare earth metal such as praseodymium, lutetium, cerium, europium and lanthanum have been used for the synthesis of metal vanadates. Herein, the choice of selected rare earth metals provide the better physiochemical and electrocatalytic properties. To increasing the electronic conductivity, the highly conducting supporting matrix is used in the fabrication process. The rare earth vanadates based nanocomposite formation was confirmed by using several analytical and spectroscopic techniques. (i) A core-shell praseodymium vanadate/sulfur-doped v carbon nitride nanosheets (PrV/SCN) nanocomposite has been developed for the electrochemical determination of metronidazole (MTZ). The electrochemical pH mechanism of MTZ was evaluated. Interestingly, the PrV/SCN modified electrode was used in analyzing the MTZ in human urine and pond water with the good acceptable result. (ii) The lutetium vanadate/graphene sheets (LuV/GRS) architectures have been successfully prepared for the detection of antibiotic drug nitrofurantoin (NFT). The LuV/GRS nanocomposite-modified electrode showed excellent electrocatalytic activity towards the reduction of NFT than pure LuV and GRS modified and unmodified electrodes. (iii) the synthesis of hierarchical nanocomposites europium vanadate nanoplates encapsulated on graphene oxide nanosheets (EuV/GO) for selective electrochemical detection of neurodegenerative drug clioquinol (CQL). The EuV/GO nanocomposite was significantly enhancing the electrochemical activity and dramatically improve the sensitivity of CQL sensor, which makes this EuVO4/GO sensor a promising platform for highly sensitive and selective detection of CQL in biological samples. (iv) 3D urchin like Cerium vanadate was interconnected with carbon nanofiber scaffold for the electrochemical detection of prostate cancer drug nilutamide. Herein, the obtained electrochemical results exhibited higher cathodic peak current and lower detection potential for the reduction of nilutamide.