Enhancement of Visible Light Driven Photoelectrochemical Performances of Hematite via Layer-by-Layer Self Assembly (LbL)

Abstract

Hematite is one of promising materials for visible light driven photoelectrochemical water splitting due to its narrow band gap, abundance and inexpensiveness. For their practical applications, however, there still remain many weakness to be solved such as low photocurrent efficiency, high onset potential for catalytic water splitting and low stability under neutral pH conditions. To address such issues, we developed a novel modification method for enhancing photocatalytic activity of hematite by utilizing layer-by-layer self-assembly (LbL) technique. We found that the surface modification of hematite with polyelectrolytes and molecular oxide catalysts led to the increase of photocurrent efficiency approximately 2 to 5 times, the decrease of onset potential, and the improvement of electrode stability against photocorrosion at the same time. In principle, our findings can be further applied to virtually any kinds of photoelectrodes and provide a general method for construction of hybrid photocatalytic systems.