Superior photoelectrochemical activity of self-assembled NiWO4–WO3 heteroepitaxy. (May 2016) - Do, Thi Hien
Abstract: Self-assembled nanocomposites with a high interface-to-volume ratio offer tremendous opportunities of tailoring functionalities by a proper combination of components. In this study, we report the first fabrication of self-assembled NiWO4 –WO3 heteroepitaxy and its excellent performance on photoelectrochemical water splitting. The heteroepitaxy is evidenced by a combination of x-ray diffraction and transmission electron microscopy. The energy band diagram of NiWO4 –WO3 heterostructure probed by x-ray photoelectron spectroscopy suggests an efficient charge separation at their interface by injecting photo-generated electrons from NiWO4 to WO3 and holes from WO3 to NiWO4 . Therefore, a great improvement in the photoelectrochemical activity of self-assembled NiWO4 –WO3 heteroepitaxy was achieved (1400 µA cm −2 at 0.7 V vs. Ag/AgCl). This work delivers a new category of composite materials for promising photoelectrode in photoelectrochemical cells. Graphical abstract: Highlights: Self-assembled NiWO4 –WO3 heteroepitaxy is successfully fabricated. Efficient charge separation is facilitated at the NiWO4 /WO3 interface. Self-assembled NiWO4 –WO3 shows a remarkable photoelectrochemical activity.