WO3 mesocrystal-assisted photoelectrochemical activity of BiVO4

Chien Nguyen Van,Wu-Ching Chou,Heng-Jui Liu,Jhih-Wei Chen,Thi Hien Do,Kai-An Tsai,Ying-Hao Chu,Chung-Lin Wu,Wen-Yen Tzeng,Yung-Jung Hsu,Haili Song,Yi-Chun Chen,Yan-Cheng Lin,Chih-Wei Luo,Rong Huang

doi:10.1038/am.2017.15

Abstract

Self-assembled nanocomposites have gained much attention over the past decade due to their intriguing properties and functionalities. In this work, we developed a self-assembled nanocomposite photoanode composed of an epitaxial BiVO4 matrix embedded with WO3 mesocrystals for photoelectrochemical (PEC) applications in the visible-light regime. The orientation of the crystal facet and interface provides a superior template to understand the intimate contact between the two constituent phases. We demonstrate that the interfacial coupling of the mesocrystal and matrix improves the separation of photoexcited carriers and the properties of charge transfer, resulting in a greatly enhanced PEC performance compared with their parent compounds. The current study demonstrates that the utilization of the interface-to-volume ratio to optimize charge interactions in the nanocomposite is essential for the advanced design of novel mesocrystal-embedded nanocomposite photoelectrodes.

Highlights

Photoelectrochemical (PEC) water splitting is the most advanced technology to convert solar energy, an abundant source of energy, into storable and friendly environmental energy in the form of hydrogen.[1,2] The current direction along this research field focuses on the development of new photocatalyst structures with highefficiency photoconversion, wide absorption of the solar spectrum and stability in electrolyte
We demonstrate that the interfacial coupling of the mesocrystal and matrix improves the separation of photoexcited carriers and the properties of charge transfer, resulting in a greatly enhanced PEC performance compared with their parent compounds
The current study demonstrates that the utilization of the interface-to-volume ratio to optimize charge interactions in the nanocomposite is essential for the advanced design of novel mesocrystal-embedded nanocomposite photoelectrodes

Summary

Introduction

Photoelectrochemical (PEC) water splitting is the most advanced technology to convert solar energy, an abundant source of energy, into storable and friendly environmental energy in the form of hydrogen.[1,2] The current direction along this research field focuses on the development of new photocatalyst structures with highefficiency photoconversion, wide absorption of the solar spectrum and stability in electrolyte. Mesocrystal systems composed of orientationally aligned functional nanocrystals have drawn much attention, because these superstructures can exhibit new functionalities due to their large surfaceto-volume ratio compared with that of single crystals.[8,9] through epitaxial growth, the mesocrystals can be embedded into an epitaxial matrix to form a new nanocomposite photoelectrode with precise control of the film orientation, a well-defined interface between constituent phases and the preclusion of unexpected factors, such as structural defects, grain boundaries and impurity phases. In this study, we attempt to use the mesocrystal-embedded system as a template to obtain a fundamental understanding of nanocomposite systems Such a model system can acquire critical information about the designed hybrid structures and provide a new architecture to explore material systems for PEC applications

Methods

Results

Conclusion