Piezo-Photocatalysis over Metal-Organic Frameworks: Promoting Photocatalytic Activity by Piezoelectric Effect

Chenxi Zhang; Da Lei; Chenfan Xie; Xiaoshuai Hang; Chuanxin He; Hai-Long Jiang

doi:10.1002/adma.202106308

Piezo-Photocatalysis over Metal-Organic Frameworks: Promoting Photocatalytic Activity by Piezoelectric Effect

Adv Mater. 2021 Dec;33(51):e2106308. doi: 10.1002/adma.202106308. Epub 2021 Oct 13.

Authors

Chenxi Zhang^{1

2

3

4}, Da Lei⁵, Chenfan Xie², Xiaoshuai Hang⁶, Chuanxin He¹, Hai-Long Jiang²

Affiliations

¹ College of Chemistry and Environmental Engineering, Shenzhen University, Shenzhen, Guangdong, 518060, P. R. China.
² Hefei National Laboratory for Physical Sciences at the Microscale, CAS Key Laboratory of Soft Matter Chemistry, Department of Chemistry, University of Science and Technology of China, Hefei, Anhui, 230026, P. R. China.
³ Key Laboratory of Optoelectronic Devices and Systems of Ministry of Education and Guangdong Province, College of Optoelectronic Engineering, Shenzhen University, Shenzhen, Guangdong, 518060, P. R. China.
⁴ School of Chemistry and Environmental Engineering, Hanshan Normal University, Chaozhou, Guangdong, 521041, P. R. China.
⁵ Xinjiang Key Laboratory of Explosives Safety Science, Xinjiang Technical Institute of Physics and Chemistry, Key Laboratory of Functional Materials and Devices for Special Environments, Chinese Academy of Sciences, Urumqi, Xinjiang, 830011, P. R. China.
⁶ Nanjing Institute of Environmental Sciences, Ministry of Ecology and Environment, Nanjing, Jiangsu, 210042, P. R. China.

PMID: 34642997
DOI: 10.1002/adma.202106308

Abstract

The built-in electric field can be generated in the piezoelectric materials under mechanical stress. The resulting piezoelectric effect is beneficial to charge separation in photocatalysis. Meanwhile, the mechanical stress usually gives rise to accelerated mass transfer and enhanced catalytic activity. Unfortunately, it remains a challenge to differentiate the contribution of these two factors to catalytic performance. Herein, for the first time, isostructural metal-organic frameworks (MOFs), i.e., UiO-66-NH₂ (Zr) and UiO-66-NH₂ (Hf), are adopted for piezo-photocatalysis. Both MOFs, featuring the same structures except for diverse Zr/Hf-oxo clusters, possess distinctly different piezoelectric properties. Strikingly, UiO-66-NH₂ (Hf) exhibits ≈2.2 times of activity compared with that of UiO-66-NH₂ (Zr) under simultaneous light and ultrasonic irradiation, though both MOFs display similar activity in the photocatalytic H₂ production without ultrasonic irradiation. Given their similar pore features and mass transfer behaviors, the activity difference is unambiguously assignable to the piezoelectric effect. As a result, the contributions of the piezoelectric effect to the piezo-photocatalysis can be clearly distinguished owing to the stronger piezoelectric property of UiO-66-NH₂ (Hf).

Keywords: metal-organic frameworks; photocatalysis; piezo-photocatalysis; piezoelectric effect.

Abstract

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