Photoelectrochemical investigation of ac modulated passive films on 304 stainless steel in weak alkaline and neutral solutions

摘要

A photoelectrochemical investigation has been carried out on an ac modulated passive film on AISI 304 stainless steel in 0 centre dot 1M Na_2B_4O_7 and 0 centre dot 5M Na_2SO_4 solutions. The results of the photocurrent measurements indicate that the photoresponse is determined by defects in the electronic structure of the films when the defects lead to localised states in the band gap region and that the photoresponse is sensitive to the passive condition and testing solutions. It is concluded that the passive film on 304 stainless steel is in a highly disordered amorphous state.