In-situ Reduction Synthesis of Bi/BiOI Heterostructure Films with High Photoelectrochemical Activity

The Bi/BiOI heterostructure films grew perpendicular to the FTO substrates were synthesized in-situ through an electrochemical deposition and hydrogen reduction method. The metallic Bi nanoparticles were decorated onto the surface of BiOI nanosheets via an in-situ reduction, induced 6.3 times improvement of photocurrent density, compared to the pristine BiOI at 1.23 V vs. reversible hydrogen electrode(RHE). The enhancement of photoelectrochemical performance was attributed not only to the efficient separation of charge resulted from surface plasmon resonance effect, but also to the fast charge transfer at the interface due to the in-situ reduction of the films. This work provided a simple and facile strategy to in-situ construct heterostructure films, and showed an effective method to improve the photoelectrochemical activity of Bi-based semiconductors.