The effective mineralization of nitrofurazone (10–100 mg L⁻¹) was performed in aqueous solutions in the presence of chloride ions by electrochemical treatment. The destruction of the organic pollutant molecules was due to their interaction with active oxygen- and chlorine-containing species forming at the inert anode (Pt/Ti or BDD) during electrolysis. Measurements of nitrofurazone concentration, chemical oxygen demand (COD) and total organic carbon (TOC) were used to estimate the removal efficiency of the pollutant. Both the pollutant oxidation rate and the degree of its mineralization were higher for the BDD anode due to the higher anode potentials on it in the course of electrolysis, which provides a high rate of active oxidizer species generation. As a result, practically full nitrofurazone molecule destruction (>99%) was achieved in 30 min at an anodic current density of 0.1 A cm⁻², a volume current density of 1.33 A L⁻¹ and pH 2 using BDD anodes. On the other hand, the nitrafurazone degradation efficiency was about 95% for Pt/Ti anodes under the same conditions. Additionally, byproducts of nitrofurazone electrooxidation were investigated by means of liquid chromato-mass-spectrometry (LC/MS). It was found that the initial decolorization of nitrofurazone solution, which occurs during the first 5 min of electrolysis, is due to the formation of a dichloro derivative of nitrofurazone, which causes the destruction of the π−conjugated bond system. Further electrolysis resulted in the almost complete destruction of the dichloro derivative within 30 min of electrochemical treatment.

Hydrogen evolution reaction on the catalytically active Ni–Re alloy is studied by the method of electrochemical impedance. The alloy was fabricated by the electrodeposition from the ammonium—citrate...

Ruddlesden–Popper (RP) transition-metal oxide phases with the general formula A_n+1B_nO_3n+1 are versatile functional materials that can accommodate a large variety of compositions without compromising structural stability. Substitutions at the A and B sites allow for the precise control of functional properties of these materials. This opens wide possibilities for rational design. In particular, some of these materials were demonstrated to be efficient and stable catalysts for electrochemical oxygen evolution reaction (OER)—one of the key processes in fuel cells and water electrolyzers. In this work, RP phases LaSrM¹_1−xM²_xO_4±δ (M¹, M²—Fe, Co, Ni) with unreported stoichiometry are prepared from aqueous solutions of metal nitrates using the ultrasonic spray-pyrolysis (USP) technique. We found that the phase purity of samples synthesized by USP is higher as compared to samples prepared by solid-state synthesis or by precipitation from aqueous solutions followed by calcination, used in previous studies of RP oxides. LaSrFe_0.5Ni_0.5O_4–δ (LSNF) oxides are found to be very active in OER in alkaline solutions, with overpotential 0.27 V at j = 0.1 A cm^–2 of visible electrode surface in a 5 M solution of KOH. This overpotential is on par with the noble-metal-based OER electrocatalysts. Moreover, the catalytic performance of LSNF in OER is found to be stable over the electrolysis time even in the strongly alkaline solution. These two factors let us conduct the water splitting process in more concentrated electrolytes decreasing the energy cost of hydrogen production by water electrolysis.