Comparative evaluation of niobium surface preparation methods for electrodeposition

To find a suitable treatment in the preparation of Nb surface for platinum electrodeposition, different methods such as thermal oxidation, anodic oxidation, mechanical roughening, and mechanical roughening with subsequent anodic etching were examined. X-ray photoelectron spectroscopy was used to study the chemical composition of depth analysis of the surface. Moreover, in order to examine the morphology and surface roughness, the samples were analyzed by Scanning Electron Microscopy (SEM) and Atomic Force Microscopy (AFM). The results showed that the most appropriate method for niobium surface preparation is mechanical roughening by shot blasting or abrading with emery and then anodic etching at the current density of 200 A/m2 for 40 min. in a solution containing 95% methanol, 2.5% hydrofluoric acid, and 2.5% hydrochloric acid at the temperature of 35 °C.