以掃描式電化學顯微鏡分析由接觸起電引起之表面電場

Investigating the Contact Electrification induced Surface Electrostatic Field using Scanning Electrochemical Microscope

林亭㚬(Ting-Jiun Lin)

指導教授 ： 林正嵐

淡江大學/工學院/化學工程與材料工程學系碩士班/碩士(2017年)

https://doi.org/10.6846/TKU.2017.00906

摘要

本研究使用靜電場輔助電鍍法(electrostatic field-assisted electrodeposition)，於銦錫氧化物(indium tin oxide, ITO)導電玻璃表面電鍍生成具微米構形之白金薄膜(micropatterned platinum thin film, mPt)。以具有微米構形之靜電膜貼附於ITO表面，移除後進行循環伏安電鍍可得mPt。以光學顯微鏡與掃描式電子顯微鏡觀察表面形貌，可知mPt由密度不同之Pt叢集所組成，且其構形尺寸與靜電膜大致相同。使用掃描式電化學顯微鏡(scanning electrochemical microscope, SECM)對其電催化性質進行分析，mPt表面Pt叢集密度較大處，具有較高催化氧氣還原反應(oxygen reduction reaction)與I-/I2氧化還原反應之能力。
為了解微米構形的電鍍機制，本研究使用SECM對經由靜電膜接觸起電程序(contact electrification)於ITO表面所造成的靜電場進行量測。於含有ferrocene methanol/ferrocenium methanol (FcM/FcM+)氧化還原對的水溶液中，分析表面靜電場對探針逼近曲線(probe approaching curve)所造成之影響，並取得表面靜電場之SECM影像。探針於ITO表面經接觸起電位置處所測得的FcM氧化電流，較於原始ITO表面所得值小，顯示表面靜電場之作用為降低ITO還原FcM+的能力。當ITO電位控制於0.1 V~ 0.2 V (vs. Ag/AgCl)時進行SECM掃描，可得清晰的微米構形靜電場影像。

關鍵字

微米構形 ； 接觸起電 ； 表面靜電場 ； 掃描式電化學顯微鏡 ； 白金

並列摘要

In this study, micropatterned platinum thin films (mPt) are successfully fabricated on the surface of indium tin oxide (ITO) conducting glass by electrostatic field-assisted cyclic voltammetric deposition. A micropatternd electrostatic film is firstly attached onto the ITO surface through contact electrification for at least 7 days, then is removed before cyclic voltammetric deposition of Pt and a mPt can thus being obtained. The surface morphology of the resulting mPt is observed using optical microscope and scanning electron microscope. It is found that its pattern dimensions are almost the same as that of the micropatternd electrostatic film, and the mPt is composed of Pt clusters with different areal densities. The electrocatalytic properties of the mPt are investigated using scanning electrochemical microscopy (SECM). The areas of mPt with high Pt cluster density have superior catalytic ability toward oxygen reduction reaction and I-/I2 redox reaction.
In order to understand the micropatterning mechanism, SECM is used to investigate the electrostatic field on the ITO surface induced by the contact electrification process. The influence of the surface electrostatic field on the probe approaching curve is analyzed in an aqueous solution containing ferrocene methanol/ ferrocenium methanol (FcM/FcM+) redox couple, and the SECM images of the surface electrostatic field under different substrate applying potentials are obtained. The probe FcM oxidation currents measured above the ITO surface which has been attached with the electrostatic film is smaller than that obtained on the original ITO surface, suggesting that the effect of the surface electrostatic field is to diminish the FcM+ reduction ability of the ITO surface. Distinct SECM images of the micropatternd electrostatic field can be acquired while the ITO substrate applying potential is controlled between 0.1 V to 0.2 V (vs. Ag/AgCl).

並列關鍵字

Micropattern ； contact electrification ； surface electrostatic field ； scanning electrochemical microscope ； platinum

參考文獻

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15.丁坤億. (2013). 以靜電場輔助電鍍具微米構形普魯士藍薄膜之研究. 淡江大學化學工程與材料工程學系碩士班學位論文, 1-108.

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