Fabrication and characterization of oxide fine-mesh electrodes composed of Sb-SnO2 and study of oxygen evolution from the electrolysis of electrolyte-free water in a solid polymer electrolyte filter-press cell: Possibilities for the combustion of organic

• Fabrication of oxide fine-mesh electrodes composed of Sb-SnO2 for the application in solid polymer electrolyte cells.
• Study of the oxygen evolution reaction during electrolysis of electrolyte-free water.
• Overpotential for the OER and the electrode service life are both affected by the Sb content.

Oxide fine-mesh electrodes composed of tin dioxide doped with antimony (OFM-Sb-SnO2) presenting different Sb contents were prepared using the thermal decomposition method on a stainless steel fine mesh support in order to obtain fluid-permeable anodes for applications in a solid polymer electrolyte filter-press cell. The surface and structural properties of the electrode materials were assessed by means of energy dispersive X-ray (EDS), X-ray diffraction (XRD) and scanning electron microscopy (SEM) techniques. Electrochemical studies were carried out using cyclic voltammetry, polarizations curves and chronopotentiometry. A Nafion® 117 membrane was used as the only electrolyte for the studies using the filter-press cell. EDS data showed that the composition of the oxide films is quite different from the nominal composition evaluated from the precursor solutions. XRD spectra revealed that the presence of Sb can change the degree of crystallinity of the SnO2 phase (rutile structure). SEM images revealed a compact surface morphology of the oxide coatings containing some distributed rectangular grains. Voltammetric curves (VCs) obtained in electrolyte-free water revealed the electrochemically active surface area and the onset of the oxygen evolution reaction (OER) are both affected by the Sb content. Polarization curves obtained in electrolyte-free water revealed the overpotential for the OER increases with the Sb content. A comparative study using a 1.0 mol dm−3 H2SO4 solution revealed that the anion of the electrolyte affects the behaviour of VCs, as well as the Tafel plots for the OER. In addition, the Tafel plots are also affected by microstructure of the oxide's surface. The endurance tests carried out under galvanostatic conditions using electrolyte-free water revealed that the electrode service life depends on the Sb content.