Ảnh hưởng của mật độ dòng, nồng độ chì nitrat và nhiệt độ của dung dịch điện ly đến hình thái, cấu trúc của lớp PbO2 kết tủa điện hóa trên vật liệu nền thép

Abstract

In this work, results of morphology, phase composition of PbO₂ layers on mild steel covered by Fe₃O₄ film formed by electrochemical method in NaOH media (PbO₂/Fe₃O₄ĐH/steel) were showned. Different parameters such as current density, concentration of lead nitrat, temperature of electrolyte, at pH = 4 were optimized. In the range of concentration from 0.25 mol/L to 1 mol/L of Pb(NO₃)₂, two phases of a-PbO₂ and b-PbO₂ were formed with the compact tetragonal shapes and different dimensions. However, b-PbO₂ form dominated, the percent of b-PbO₂ form increases when concentration of Pb(NO₃)₂ in elctrolyte rises. Phase composition of PbO₂ layers  were affected strongly by temperature of electrolyte, at 15 ^oC, b-PbO₂ form reached 81.87 % and a-PbO₂ only 14.92 %. However, at 50 ^oC, a-PbO₂ form dominated with 91.93 %, and b-PbO₂ only 4.33 %.

Keywords. Electrodeposition, b-PbO₂, a-PbO₂, mild steel.