Exploring the significance of carbonaceous support in the synthesis of electrochemically active nanomaterials and the fabrication of electrochemical sensors

• Main Author: Natarajan Karikalan
• Other Authors: Shen-Ming Chen
• Format: Others
• Language: en_US
• Published: 2018
• Online Access: http://ndltd.ncl.edu.tw/handle/26h5z2

博士 === 國立臺北科技大學 === 能源與光電材料專班 === 106 === Carbon based nanomaterials (CBMs) have exposed admirable physicochemical properties that attracted tremendous interest in various research fields. These materials are also considered ideal matrixes for the development of highly sensitive electrochemical sensors. Their contributions are inevitable in the forefront of chemical research and electrochemical sensing platforms. Therefore, the scrutiny of chemistry behind the influence of carbonaceous material should be accounted. This thesis certainly focuses the profound significance of CBMs in the modern synthesis and the electrode fabrications. In order to obtain the active CBMs, different facile synthesis protocols are employed viz., flame synthesis (for sulfur doped carbon, SDCN), sonochemical approach (for sulfur doped reduced graphene oxide, S-rGO), chemical activation (for activated graphite, aGR) and electrochemical activation (for activated screen printed carbon electrode, ASPCE) process. The physicochemical properties of CBMs and their participation in the synthesis of nanomaterials and electrode fabrications are thoroughly discussed. The discussions are organized into two main contexts, (i) synthesis of electrochemically active nanomaterials (EANMs) by using the CBMs and (ii) direct fabrication of sensor electrodes by the CBMs. In synthesis, the SDCN or S-rGO are playing a key role to produce EANMs where it provides supportive matrixes and also act as mild oxidizing agents. Herein, the nickel ions are adsorbed on the SDCN surface which helps to promote the nickel hydroxide (Ni(OH)2) formation without any external oxidant. The as-prepared Ni(OH)2/SDCN composite is applied to the determination of glucose and received excellent activity when compared with bulk Ni(OH)2. Likewise, the S-rGO has given room to the formation of CuS besides it is slightly changed their structure from covellite to digenite phase by the oxidation. When compared with bulk CuS (covellite), the oxidized form of CuS (digenite) exhibited the better electrocatalytic activity to the glucose determination. In both cases, the sulfur dopant has taken the leading role to oxidize the nickel ions to Ni(OH)2 or covellite to digenite. In direct fabrication, the edge plane activity of ASPCE and aGR are investigated in the electrocatalysis of catecholic derivatives (catechol, caffeic acid, dopamine and hydroquinone) and nitroaromatic compounds (flutamide, methyl parathion, 4-nitro aniline and 4-nitro phenol), respectively. Herein, the electrochemical reactivity of ASPCE and aGR is uncontrollable with catecholic or nitroaromatic compounds, because, these two groups are having electrochemically identical active groups such as catechol or nitrobenzene skeleton. Thereby, the resultant electrochemical behavior of catechol (or nitrobenzene) is overlap with one another to the analogues of catechol (or nitrobenzene) respectively. These effects of interference on the electrochemical signals are examined and documented thoroughly.