Electrochemical Behavior of o‐Nitrophenol at Hexagonal Mesoporous Silica Modified Carbon Paste Electrodes

Abstract

A hexagonal mesoporous silica (HMS) modified carbon paste electrode (CPE) was fabricated and characterized by cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS) methods (ferrocene as a probe). The electrochemical behavior of nitrophenol (o-NP) at the HMS modified electrode (HMSCPE) was investigated. Compared with CPE, a well-defined reduction peak and a remarkably peak current response was observed. It is indicated that mesoporous HMS exhibited remarkable enhancement effects on the electrochemical reduction of o-NP. The electrochemical reduction mechanism was also discussed. Consequently, a simple and sensitive electrochemical method was proposed for the determination of o-NP, which was used to determine o-NP in waste water samples.

An Easily Fabricated Electrochemical Sensor Based on a Graphene-Modified Glassy Carbon Electrode for Determination of Octopamine and Tyramine

“…The value of the slopes for OA and TA is close to an expected Nernstian slope. On the other hand, according to the following formula [ 47 ]: where m and n are the participating number of protons and electron transfer number in the reaction respectively. The ratio of m/n at ERGO/GCE was calculated to be approximately 1, suggesting that the equal numbers of protons and electrons were transferred in both electrochemical oxidation reactions of OA and TA.…”

An electrochemical sensor based on polyelectrolyte-functionalized graphene for detection of 4-nitrophenol

“…The linear regression equation can be expressed as E pc (V) = À0.045pH À 0.364 (R 2 = 0.9925). According to the following formula of dE pc / dpH = (2.303mRT)/(nF) [46], where m is the number of proton, n is the number of electron, R, T and F have their usual meanings. Thus, the proton transfer number (m) was calculated to be 2, suggesting that the electrochemical reduction of 4-NP on the PDDA-G/GCE should be a two-electron and two-proton process.…”

Ultrasensitive Detection of Ferulic Acid Using Poly(diallyldimethylammonium chloride) Functionalized Graphene-Based Electrochemical Sensor

“…A good linear relationship between E pa and pH was constructed (a) with a linear regression equation expressed as E pa = 0.4955–0.0623 pH, R 2 = 0.9969 ( E pa : V). According to Nernst equation E pa = E θ − [(2.303 mRT)/(nF)] pH [38, 40], the ratio of m / n was calculated as 1.06; this finding showed that the numbers of transferred electrons and protons were equal during the electrode reaction, and the result was consistent with those in previous reports [14, 16]. Moreover, the maximum oxidation peak current was achieved at pH 3.0 (b).…”