Pretreated Graphite Electrode Research Articles

Electroanalytical determination of Allura Red in beverage samples using an anodically pretreated graphite electrode

ABSTRACT In this study, an anodically pretreated pencil graphite electrode (Ptre/PGE) which has oxygen-containing groups was used for the electrochemical determination of Allura Red (AR) by differential pulse voltammetry (DPV) method for the first time in the literature. In order to be more selective and sensitive the pencil graphite electrode, the anodic pretreatment process was performed by applying a constant +1.8 V potential for 250 s in pH 9 phosphate buffer solution using chronoamperometry method. The characterisation studies of the sensor were performed using cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS), Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), and atomic force microscopy (AFM) methods. Interference effects of sunset yellow, tartrazine, amaranth, aspartame, glucose, gelatin, and ascorbic acid on AR determination with Ptre/PGE were investigated. The limit of detection and quantitation values was found as 75 and 251 nmol L−1, respectively. The Ptre/PGE has been used for the determination of AR in cherry juice and energy drink samples, where it provides recovery ranging from 98.40% to 100.8%.

Effects of the catalyst embedded conditions on the electrochemical properties of the grown in situ carbon nanotube chemically modified electrode

Grown in situ carbon nanotube chemically modified electrode (GSCNT-CME) was prepared by the in situ growth of carbon nanotube (CNT) onto a pretreated graphite electrode (GE) via catalytic chemical vapor deposition. The pretreated GE was prepared by direct current electrochemical deposition using a nickel catalyst. Influence of the catalyst direct current electrochemical deposition to the electrochemical property of the GSCNT-CME was discussed, and found the obtained GSCNT-CME possessed the best electrochemical properties when the deposition voltage was 2.0V and the deposition time was 5min. The GSCNT-CME not only had good electrochemical performance. And distribution of the CNT size in diameter was uniform, which had potential importance for study the influence of the catalyst pre-preparation conditions to the electrochemical property of the GSCNT-CME.

Detection Trace Copper by Carbon Nanotube Chemically Modified Electrode via Flame Synthesis

The grown in situ carbon nanotube chemically modified electrode (GSCNT-CME) was prepared by growing carbon nanotube (CNT) in situ on the pretreated graphite electrode (GE) via a liquid ethanol flame. The GSCNT-CME was applied to detect the trace copper in water. The researching results showed that the GSCNT-CME has good electrochemical detection sensitivity and accuracy in the detection of trace copper in water.

Preparation and characterization on the carbon nanotube chemically modified electrode grown in situ

Carbon nanotube chemically modified electrode (CNT-CME) was prepared by growing carbon nanotube (CNT) in situ on the pretreated graphite electrode (GE) via the catalytic chemical vapor deposition. The pretreated GE was prepared by ultrasonic immersion method using Ni(NO 3) 2 as the catalyst. The CNT growing on the CNT-CME was characterized by transmission electron microscope and scanning electron microscope. The obtained electrode electrochemical performance was characterized by cyclic voltammetry with the Na 2SO 4 solution and [Fe(CN) 6] 3−/[Fe(CN) 6] 4− solution. The results showed that the obtained electrode has good current responsive sensitivity and good testing result accuracy, indicating that the obtained electrode may have great application in electrochemical testing field.