Spectroscopic, electrochemical, and corrosion inhibition studies of V2O5-Modified phosphate glasses

Abstract

In this study, we investigated the synthesis of vanadate-based glasses with the following compositions: 50V₂O₅–50P₂O₅, 50V₂O₅–25P₂O₅–25BaO, and 50V₂O₅–50BaO. The glass network structure was analyzed using various analytical techniques, including Fourier transform infrared spectroscopy and X-Ray Photoelectron Spectroscopy, which provided insights into the bonding and coordination of the components. Vanadium in these glasses exists in two oxidation states, V⁴⁺ and V⁵⁺, and forms V–O–V, V–O–P, and V–O–Ba bridges.

Electrochemical analysis using cyclic voltammetry on a platinum electrode in 1.0 M HCl was conducted to explore the redox behaviour of the V⁵⁺/V⁴⁺ couple. Finally, corrosion inhibition properties were assessed on mild steel in the same acidic medium, providing a comprehensive evaluation of the materials' performance in a practical context. Thus, for 250 ppm of inhibitor, the glass composition of 50V₂O₅–50P₂O₅ exhibits inhibition efficiencies of 97.7 % and 92.2 % for the two media 1.0 M and 5.0 M, respectively. Its mode of action is explained by electrochemical analyses and surface analyses.