Improvement of CuFeO₂/Fe photocathodes by applying a posttreatment

Abstract

CuFeO₂ is a prospective photocathode material for photoelectrochemical water-splitting with elemental strategic approaches point of view. In our previous study, we have demonstrated the direct fabrication of CuFeO₂ films from an Fe substrate for enhancing adhesion strength of photocathode and current collector interface. We confirmed their photocatalytic response to visible light as photocathode; however, both their hydrogen overvoltage and corresponding current density were not enough as compared to theoretical efficiency. It is due to a lack of acceptor density in CuFeO₂ film. In this paper, we studied the post-treatment effects to the CuFeO₂/Fe photocathodes. Our systematic studies revealed that post-annealing and acid treatments provided the positive effects even on CuFeO₂ films directly fabricated by hydrothermal method.