Titanium Vacancies in TiO₂ Nanofibers Enable Highly Efficient Photodriven Seawater Splitting

Graphical Abstract

“We think this can provide new insight into the design of high-performance catalysts for seawater splitting.” Read more about the story behind the cover in the Cover Profile and about the research itself on page 14202 ff. (DOI: 10.1002/chem.202101817).

Abstract

Invited for the cover of this issue are Xiao-Yu Yang and co-workers at Wuhan University of Technology, Heinrich-Heine-Universität Düsseldorf, University of the Witwatersrand, and Ben-Gurion University of the Negev. The image depicts Ti vacancies in TiO₂ as powerful drivers of photo- and photo-electrocatalytic seawater splitting for hydrogen production. Read the full text of the article at 10.1002/chem.202101817.

What is the most significant result of this study?

The photodriven seawater-splitting performance of TiO₂ with rich Ti vacancies was originally investigated. We found that the excellent activity and stability in seawater splitting are strongly associated with the unidirectional electron trap and superior H⁺ adsorption ability of Ti vacancies. We think this can provide new insight into the design of high-performance catalysts for seawater splitting.

What was the inspiration for this cover design?

When we got the invitation to provide a cover image, we thought of the key revelations in our work to feature in the image: how Ti vacancies in TiO₂ greatly improve the performance of photodriven seawater splitting. Therefore, we first built a model of TiO₂ with Ti vacancies and the background is seawater with sunlight. The unidirectional electron trap and H⁺ adsorption were emphasized by the lighting and the gathering of H⁺ around the Ti vacancies.

What are the significance and challenges of photodriven seawater splitting?

Photodriven seawater splitting could combine rich ocean resources and sustainable solar energy for hydrogen production without the need for energy-demanding pre-desalination, thereby saving freshwater. This would be one of the most ideal ways to help solve the energy problem. Based on our research on photodriven seawater splitting, we believe there are some issues that need to be addressed for the realization of this critical sustainable energy technology. Firstly, how to eliminate the influence of impurity ions in seawater on the catalyst and the reaction. Secondly, how to improve the solar-to-hydrogen efficiency by material design and synthesis. Finally, how to build a large-scale H₂ production system by the sea.