【摘要】：穩(wěn)態(tài)循環(huán)伏安法具有簡單、快速判別電極性能和估算電極尺寸的特性,因而被廣泛應(yīng)用于超微電極的表征.但納米電極由于尺寸極小,其表面形貌的細(xì)微變化對電化學(xué)行為有明顯的擾動,從而影響納米電極表征的準(zhǔn)確性.結(jié)合電化學(xué)實驗和有限元模擬,探討了納米電極尺寸、絕緣層半徑和電極半徑之和與電極半徑之比(RG)和尖端孔道對穩(wěn)態(tài)電流的影響.研究表明尺寸較小(r≤80 nm)的納米圓盤電極,由于反應(yīng)速率相對擴(kuò)散較慢,電極反應(yīng)過程受動力學(xué)效應(yīng)控制,使穩(wěn)態(tài)電流曲線偏離半球形擴(kuò)散控制的標(biāo)準(zhǔn)"S"型.此外RG值較小的納米圓盤電極,物質(zhì)到電極的傳遞被增強(qiáng),使極限電流值增大.我們對內(nèi)嵌式納米電極進(jìn)行了進(jìn)一步研究,并發(fā)現(xiàn)電極尖端孔道阻礙了電活性物質(zhì)的擴(kuò)散,削弱了動力學(xué)的限制,使極限電流值低于同尺度的納米圓盤電極,伏安電流曲線呈現(xiàn)標(biāo)準(zhǔn)的"S"型.本研究系統(tǒng)地探討了電極尖端形貌與穩(wěn)態(tài)電流的相互關(guān)系,加深了對納米電極電化學(xué)行為的理解.
[Abstract]:Steady-state cyclic voltammetry has been widely used in the characterization of ultra-micro electrodes because of its simple and rapid identification of electrode performance and estimation of electrode size. However, due to the very small size of the nano-electrode, the surface morphology of the nano-electrode has obvious disturbance to the electrochemical behavior, which affects the accuracy of the characterization of the nano-electrode. Based on the electrochemical experiments and finite element simulation, the effects of the size of the nano-electrode, the ratio of the insulator radius, the sum of the electrode radius and the electrode radius to the electrode radius (RG) and the tip channel on the steady-state current were investigated. The results show that for the nano-disk electrode with smaller size (r 鈮，

本文編號：2461669