Electrodeposition and characterization of Fe-Mo alloys as cathodes for hydrogen evolution in the process of chlorate production

Fe-Mo alloys were electrodeposited from a pyrophosphate bath using a single diode rectified AC current. Their composition and morphology were investigated by SEM, optical microscopy and EDS, in order to determine the influence of the deposition conditions on the morphology and composition of these alloys. It was shown that the electrodeposition parameters, such as: chemical bath composition and current density, influenced both the composition of the Fe Mo alloys and the current efficiency for their deposition, while the micro and macro-morphology did not change significantly with changing conditions of alloy electrodeposition. It was found that the electrodeposited Fe Mo alloys possessed a 0.15 V to 0.30 V lower overvoltage than mild steel for hydrogen evolution in ail electrolyte commonly used in commercial chlorate production, depending on the alloy composition, i.e., the conditions of alloy electrodeposition

Seawater zinc/polypyrrole-air cell possessing multifunctional charge-discharge characteristics

An environmentally friendly cell using polypyrrole-air regenerative cathode and zinc as anode is investigated in the 3% sodium chloride solution. The cell can operate in different charge and discharge mode. Polypyrrole can be reoxidized (doped) with chloride anions either by using dissolved oxygen or by an external power supply, e.g., small photovoltaic cell. In that way, after discharge, capacity retaining can be achieved by using seawater as the electrolyte. During low discharge rate, the delicate balance between solid state diffusion-controlled dedoping and chemical oxidation of polypyrrole produced by hydrogen peroxide is achieved, generating stable voltage plateau. The cell is proposed to operate as a power supply for different sensor devices in two modes. In the low discharge mode (10-20 mA g(-1)), it can be used for data acquisition, and at the fast discharge mode (up to 2 A g(-1)) for collecting data transmission

Electrochemical decolorization of CI Acid Orange 3 in the presence of sodium chloride at iridium oxide electrode

The electrocatalytic degradation of C.I. Acid Orange 3 from simulated wastewater by indirect electrochemical oxidation using an IrOx electrode was investigated. The effects of different operating parameters on the rate of dye decolorization were studied. The influences of mixing, electrolyte concentration, applied current, and initial dye concentration were examined. The change in dye concentration was followed by ultraviolet-visible spectroscopy, while the formation of reaction intermediates was established using high-performance liquid chromatography-mass spectrometry analysis. Ultraviolet-visible spectroscopy showed a decrease of the absorption peak at 374 nm during the electrolysis and the appearance of a new absorption maximum at 460 nm. The decolorization reaction can be followed only at 460 nm. Four intermediate products (two mono- and two dichlorinated) were detected. At the end of the study, a phytotoxicity assay was performed to determine the effectiveness of the applied method. The results showed that the applied electrochemical treatment of C.I. Acid Orange 3 leads to a decrease in phytotoxicity from 53 to 28%