A nanostructured AuCu3 alloy electrode for highly sensitive detection of hydrazine at low potential in neutral medium

Amperometric determination of hydrazine using a CuS-ordered mesoporous carbon electrode

An electrocatalytic sensor for hydrazine using copper sulfide-ordered mesoporous carbon (CuS-OMC) is described. A facile solvothermal synthetic strategy was adopted for CuS-OMC and the ordered mesoporous carbon was obtained through nanocasting method. The synthesized CuS-OMC was characterized using microscopic and spectrochemical techniques. CuS-OMC was immobilized on GCE and evaluated for its electrochemical sensing of hydrazine using cyclic voltammetry and amperometry. CuS-OMC modified GCE exhibited better hydrazine sensing at an optimized pH 7.4 in terms of oxidation potential and current compared with that of GCE, CuS, and OMC. The observed sensing performance of CuS-OMC was attributed to the presence of Cu (I/II) in CuS dispersed in OMC which acts as an electrocatalytic center for the sensing of hydrazine. Amperometry under optimized experimental condition with an applied potential of 270 mV was employed to obtain a linear calibration plot in the range 0.25 to 40 μM (R² = 0.9908) with a detection limit of 0.10 μM with a sensitivity of 0.915 (± 0.02) μA cm^-2 μM^-1. Real sample analyses were carried out by spiking of hydrazine in different water samples and the recoveries were in the range of 97 ± 2.1% (n = 3). Graphical abstract.

Micelles Mediated Zone Fluidics Method for Hydrazine Determination in Environmental Samples

An automated flow method for the determination of hydrazine based on the concept of zone-fluidics has been developed. The analyte reacts under flow conditions with p-dimethylamino benzaldehyde (25 mmol L-1) in micellar medium (100 mmol L-1 SDS) to form a stable derivative (460 nm). Micelles mediated catalysis excludes the use of highly acidic environment typical for this kind of reaction. Following careful examination of chemical and instrumental variables, the method allows the determination of hydrazine at the low micromolar level (0.3-10 μmol L-1) in water samples. Real sample analyses (drinking and boiler feed water) resulted in satisfactory results in terms of accuracy with the percent recoveries being in the range of 82-114%.

Formate: A Possible Replacement for Formic Acid in Fuel Cells

We present a facile thermodynamic strategy for identifying formate electrooxidation at a Pt electrode in a fuel cell. Mixtures of formate and sulfuric acid are used as fuel solutions for maintaining formic acid at a low concentration and reducing CO poisoning of the Pt electrode. Pt is modified by a polyaniline porous film to improve the electrocatalytic activity towards formate oxidation. The result indicates that formate can bypass the poisoning path to form CO2 at a low potential. Additionally, we propose a new mechanism of formate electrooxidation and investigate the possibility of an independent oxidation path starting from free formate in solution.

Electrochemical fabrication of gold nanoparticles decorated on activated fullerene C60: an enhanced sensing platform for trace level detection of toxic hydrazine in water samples

Schematic representation for fabrication of AC60–AuNPs composite modified SPCE and sensing of hydrazine.