Synthesis and study by FTIR, 31P NMR and electrochemical impedance spectroscopy of vanadium zinc phosphate glasses prepared by sol–gel route

•Zinc–vanadium–phosphate glasses•The sol–gel method saves energy.•Structure has been investigated by IR and 31P NMR spectra.•EIS has been successfully applied to the study of corrosion systems.

Ternary phosphate glasses of the system (ZnO)(0.45 − x)–(P2O5)(0.55 − y)–(V2O5)z, (y = 0; x = z = 0.01, 0.1; 0.2) and (x = 0, y = z = 0.1; 0.2) are prepared via the sol–gel process using zinc acetate, ammonium metavanadate and phosphoric acid as precursors. Spectroscopic investigations reveal a phosphate glass system depolymerization by systematic conversion of PO3− metaphosphate chains into (P2O7)4 − pyrophosphate, with the formation of P–O–V and V–O–V bonds, which replace P–O–P ones. Heat treatment of the dried xerogels containing 10% of V2O5 at temperatures 400–600 °C shows a similar trend in their infrared spectrum then that of glass obtained by melt quenching at 1000 °C. Inhibitive effect of the glass composition (ZnO)0.45–(P2O5)0.45–(V2O5)0.1 obtained at 600 °C and 1000 °C in simulated water was studied by electrochemical impedance spectroscopy (EIS). Inhibitory efficiency for both samples is the same ~ 95%.