Effect of ZnO on the corrosion of zinc, Q235 carbon steel and 304 stainless steel under white light illumination

This paper discusses the effects of the coupling of ZnO-Zn, Q235 carbon steel, and 304 stainless steel on their corrosion in 3.5% NaCl under white light illumination. In the presence of Na2S, ZnO provided photoelectrochemical cathodic protection for the coupled metals. In the absence of Na2S, ZnO could only provide photoelectrochemical cathodic protection for 304 stainless steel. Under white light illumination, the open circuit potential of ZnO photoelectrode shifted in the negative direction. ZnO provided photoelectrochemical cathodic protection to the metals only when the open circuit potential of ZnO photoelectrode was more negative than that of the metals.