Cobalt Hexacyanoferrate-Decorated Titania Nanotube: CoHCF@TNT Modified GCE as an Electron Transfer Mediator for the Determination of Hydrazine in Water Samples

Abstract

The cobalt hexacyanoferrate-decorated titania nanotube (CoHCF@TNT) was prepared by dispersing 100 mg of titania nanotube (TNT) to a solution of an equimolar concentration of CoCl 2 · 6H 2 O and K 3 [Fe(CN) 6 ] containing 0.05 M KCl solution (35 mL). The TNT was synthesized by hydrothermal method using Degussa P-25 TiO 2 in 2 M NaOH as reported in the literature. The CoHCF@TNT was isolated and characterized by DRS-UV, FE-SEM, FT-IR, and XRD analysis. The electrochemical behavior of the CoHCF@TNT was carried out in 0.1 M phosphate buffer. The CoHCF@TNT modified system showed an excellent electron transfer mediator for the oxidation of hydrazine at +0.5 V versus Ag wire. The proposed method can be utilized for the amperometry detection of hydrazine from environmental samples. A calibration plot was constructed by plotting the concentration of hydrazine against the peak current. The current response was linear in the ranges of the hydrazine concentration from 5 × 10 −4 M to 2.5 × 10 −3 M with a slope of 72.8 μAmM −1 and the linear correlation coefficient of 0.9972. The detection limit was found to be 1 × 10 −3 M.

Hydrazine electrooxidation mediated by transition metal octaethylporphyrin-modified electrodes

“…Mean LOD and LOQ was 0.0518 and 0.173 mmol L À1 , respectively. These values are comparable to previously reported studies with other systems [27][28][29] (Table S1, ESI †), considering the quick and simple way to obtain this modified system, and, on the other hand, the pH of the solution, lower than the hydrazine pK a value of 7.9, 30,31 which means that most of the hydrazine available at the solution is its protonated form (more difficult to oxidize). Finally, from the obtained curves, an average calibration curve is worked out, whose linear regression fits the relationship I p (A) = 3.25 Â 10 À5 AE 1.13 Â 10 À6 [N 2 H 4 ] (mmol L À1 ) + 4.32 Â 10 À6 (A), with a correlation coefficient (R 2 ) 0.998.…”

Synthesis of Chitosan Protected Nickel Hexacyanoferrate Modified Titanium Oxide Nanotube and Study its Application on Simultaneous Electrochemical Detection of Paracetamol and Caffeine

“…The peaks at the 2Ɵ values of 11.3°, 24.5° and 48.0° are corresponds to the crystal planes of (020), ( 110) and ( 200) which suggests the crystalline structure of lepidocrocite-type TNT. Compared to the pure TNT [21], the peak at 11.3° didn't show any changes after the intercalation of NiHCF. This indicates that the interlayer spacing of TNT was not expanded when the deposition of NiHCF.…”

“…The peak at 3735 cm -1 is due to the -O-H group of water molecules. Compared with the pure TNT [21], the vibrational energy of the peak at 914 cm -1 is decreased due to intercalation of NiHCF with TNT. These results prove that the formation of NiHCF modified TNT.…”

Review—Prussian Blue and Its Analogs as Appealing Materials for Electrochemical Sensing and Biosensing

“…[137][138][139] The development of electrochemical sensors for its detection is based on the possibility of oxidizing hydrazine to N 2 due to the electrocatalytic activity of the PBA that allows reducing the applied overpotentials. Some examples of electrochemical hydrazine sensors are based on PB, 132,133,139,140 CoHCF, 138,141,142 NiHCF, 143,144 CuHCF, 137 AgHCF, 145 and RuHCF. 104 Another important application of the PBA consists in the detection of explosives.…”