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

摘要

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 degrees C shows a similar trend in their infrared spectrum then that of glass obtained by melt quenching at 1000 degrees C. Inhibitive effect of the glass composition (ZnO)(0.45)-(P2O5)(0.45)-(V2O5)(0.1) obtained at 600 degrees C and 1000 degrees C in simulated water was studied by electrochemical impedance spectroscopy (EIS). Inhibitory efficiency for both samples is the same similar to 95%. (C) 2015 Elsevier B.V. All rights reserved.