Electrocatalytic activity of calcined manganese ferrite solid nanospheres in the oxygen reduction reaction.

In this study, we synthesized MnFeO solid nanospheres (MSN) calcined at different temperatures (200-500 °C) and MSN-based materials mixed with carbon black, for their use as electrocatalysts in the oxygen reduction reaction (ORR) in alkaline medium (0.1 M KOH). It was demonstrated that the calcination temperature of MSN material determined its chemical surface composition and microstructure and it had an important effect on the electrocatalytic properties for ORR, which in turn was reflected in the performance of MSN/CB-based electrocatalysts.

Physicochemical characteristics of calcined MnFeO solid nanospheres and their catalytic activity to oxidize para-nitrophenol with peroxymonosulfate and n-C asphaltenes with air.

Manganese ferrite solid nanospheres (MSNs) were prepared by a solvothermal method and calcined at various temperatures up to 500 °C. Their surface area, morphology, particle size, weight change during calcination, surface coordination number of metal ions, oxidation state, crystal structure, crystallite size, and magnetic properties were studied. The MSNs were used as catalysts to activate potassium peroxymonosulfate (PMS) for the oxidative degradation of para-nitrophenol (PNP) from water and for the oxidation of n-C asphaltenes in flowing air at atmospheric (0.

Removal of Phenolic Compounds from Water Using Copper Ferrite Nanosphere Composites as Fenton Catalysts.

Copper ferrites containing Cu ions can be highly active heterogeneous Fenton catalysts due to synergic effects between Fe and Cu ions. Therefore, a method of copper ferrite nanosphere (CFNS) synthesis was selected that also permits the formation of cuprite, obtaining a CFNS composite that was subsequently calcined up to 400 °C. Composites were tested as Fenton catalysts in the mineralization of phenol (PHE), -nitrophenol (PNP) and -aminophenol (PAP).

Removal of bisphenols A and S by adsorption on activated carbon clothes enhanced by the presence of bacteria.

This study investigated the adsorption of two endocrine-disrupting chemicals, bisphenol A (BPA) and S (BPS), from water using activated carbon clothes (ACCs), as-received and oxidized, in the absence and presence of bacteria, analyzing both kinetic and equilibrium adsorption data. Kinetic study of the different systems showed that the adsorption rate was affected both by the oxidation of the adsorbent and by the presence of bacteria. Bisphenol adsorption kinetics followed a second-order kinetic model, with rate constants between 0.

Effect of calcination temperature of a copper ferrite synthesized by a sol-gel method on its structural characteristics and performance as Fenton catalyst to remove gallic acid from water.

A copper ferrite synthesized by a sol-gel combustion method was calcined at different temperatures up to 800°C, determining changes in its structural characteristics and magnetic measurements and studying its catalytic performance in gallic acid removal by Fenton reaction. The main objective was to study the effect of the calcination temperature of copper ferrite on its crystalline phase formation and transformation, activity and metal ion leaching. The cubic-to-tetragonal transformation of the spinel occurred via its reaction with the CuO phase, displacing Fe ions in B (octahedral) sites out of the spinel structure by the following reaction: 2Fe+3CuO→FeO+3Cu.