Formation of Nanoporous Tin Oxide Layers on Different Substrates during Anodic Oxidation in Oxalic Acid Electrolyte

Abstract

Nanoporous tin oxide layers were obtained on various Sn substrates including high- and low-purity foils and wire by one-step anodic oxidation carried out in a 0.3 M oxalic acid electrolyte at various anodizing potentials. In general, amorphous oxide layers with the atomic ratio of Sn : O (1 : 1) were grown during anodization, and a typical structure of the as-obtained film consists of the “outer” layer with less regular, interconnetted pores and the “inner” layer with much more uniform and regular channels formed as a result of vigorous gas evolution. It was found that the use of electrochemical cell with the sample placed horizontally on the metallic support and stabilized by the Teflon cover, instead of the typical two-electrode system with vertically arranged electrodes, can affect the morphology of as-obtained layers and allows fabrication of nanoporous oxides even at anodizing potentials up to 11 V. An average pore diameter in the “outer” oxide layer increases with increasing anodizing potential, and no significant effect of substrate purity on the structure of anodic film was proved, except better uniformity of the oxides grown on high-purity Sn. A strong linear relationship between the average steady-state current density and anodizing potential was also observed.

CdS-Decorated Porous Anodic SnOx Photoanodes with Enhanced Performance under Visible Light

“…The process was performed in a two-electrode system with Sn sample and Pt grid serving as an anode and cathode, respectively (for a detailed description of the experimental setup, see ref. [ 28 ]). Anodization was carried out at room temperature in a 1 M NaOH solution under the constant potential difference of 4 V for 50 min.…”

Improving the photoelectrochemical performance of porous anodic SnO x films by adjusting electrosynthesis conditions

“…The process was carried out in a typical two‐electrode cell with the low purity Sn foil (98.8%, Goodfellow) and Pt grid serving as an anode and cathode, respectively (for more details see ref. [45]). A 1.0 M sodium hydroxide solution was used as the electrolyte.…”

Electrochemistry at Krakowian research institutions

“…The team specialized in Electrochemistry, previously guided by Professor Marian Jaskuła, and now by Professor Grzegorz Sulka, and has been working at the Faculty of Chemistry. The group has impressive achievements in fields of anodization of Al [152][153][154][155]; electrochemical synthesis of nanostructured oxides of, e.g., Sn [156,157] and Zn [158,159]; and nanoporous titanium dioxide [160][161][162]. The obtained anodic alumina oxide (AAO) templates are widely used for the fabrication of nanostructured electrodes of metals [163], alloys [164,165], and polymers [166,167].…”