AIBN Seminar Series Dipole Moment Tuning in Semiconductor Photoelectrodes

We are pleased to present Zhiliang Wang and Lianzhou Wang to speak on the topic Dipole Moment Tuning in Semiconductor Photoelectrodes.

When: Thursday 26th October

Where: AIBN Level 1 Seminar room or online via zoom click here to join

Time: 11am-12pm

Abstract

The charge separation and transfer (CST) in photoelectrodes is regarded as the most crucial step for efficient solar energy conversion via photoelectrocatalysis. To accelerate the CST process, it is important to create strong electric field to enhance band bending in the semiconductors. Dipole moment created by defects, or the intrinsic dipoles can be applied to induce an additional depolarized electric field, leading to improved driving force for CST. In our research, lattice distortion via lithiation process is created in semiconductor photoelectrodes, which leads to the formation of defect dipoles in the photoelectrode. It can lead to bulk electric field to facilitate the CST for water splitting. Further researches based on ferroelectric photoelectrode BiFeO₃ show that these intrinsic dipoles can also be tunned via external poling treatment, wherein the aligned dipole moment can lead to precisely control of the band bending degree, leading to adjustable charge separation and transfer efficiency in the ferroelectric BiFeO₃ photoelectrode. These findings have displayed how the break of symmetry in localized microstructure can be tuned and finally affect the dynamics of charge carrier transfer via dipole moment. It can inspire the design of more effective solar energy conversion processes.

References

1. A. Guinier, X-ray diffraction in crystals, imperfect crystals, and amorphous bodies, Courier Corporation, 1994
2. Y. Hu, Z. Wang, L. Wang, et al., Nat. Commun., 2020, 11, 219.
3. J. Wang, Z. Wang, Y. Hu, et al., ACS Nano, 2022, 16, 21248.
4. Z. Wang, L. Wang, et al., Angew. Chem., 2019, 131, 1024

Bio

Dr Zhiliang Wang is an ARC DECRA fellow in The University of Queensland. He has focused on renewable energy conversion processes, including water splitting, carbon dioxide fixation and methane conversion. He has accumulated rich experiences in the design of photocatalysts and photoelectrodes and achieved over 80 publications in highly ranked journals with over 6000 citations. He has been awarded with the J G Russell Award by the Australia Academy of Science, ECR Research Award by UQ and other prizes. Recently, he has been awarded the ARC Future Fellowship.