Hydrogen fuel conversion can be improved in bismuth vanadate

Scientists have highlighted bismuth vanadate as a promising material for producing clean energy in the form of hydrogen fuel. However, the amount of energy produced was far lower than predicted theoretically.

Choi investigated how mechanical strain can influence the performance of devices containing bismuth vanadate. The strain occurs in the vanadate when it is mixed with other materials, such as titanium dioxide, to produce these promising photocatalytic devices.

Choi found tensile strain changes bismuth vanadate’s crystal and electronic structure, leading to better water splitting and hydrogen production. He reported hydrostatic and in-plane biaxial strain linearly changes with certain electronic and mechanical properties of the material.

This investigation sheds insights on how controlling the synthesis of this material can help optimize hydrogen production in a fuel cell.

“Fundamental understanding of strain effects on BiVO₄ and its heterosystems, which remains largely lacking, is prerequisite in order to achieve improved and controllable performance,” said author Minseok Choi.

To obtain his results, Choi used quantum mechanical simulations to model three types of bismuth vanadate, which had different crystal structures. With the structures precisely modeled, it was possible to predict the resulting electronic and mechanical properties of these structures and compare them to an unstrained bismuth vanadate.

“This information will be of great interest to the large community of physicists and materials scientists interested in the strain effects on photocatalytic and photoelectrochemical properties, as well as researchers interested in electronic, optical, and energy applications for future technology,” Choi said.

Source: “Photocatalytic and photoelectrochemical activities of strained BiVO₄,” by Minseok Choi, Applied Physics Letters (2021). The article can be accessed at https://doi.org/10.1063/5.0047804 .

This paper is part of the Materials for Renewable Fuels Production Collection, learn more here .