Direct Z-scheme MoSe2/TiO2 heterostructure with improved piezoelectric and piezo-photocatalytic performance

Qing Han; Shiwen Du; Yumin Wang; Ziwu Han; Hongjing Li; Hu Xu; Pengfei Fang

doi:10.1016/j.jcis.2022.04.139

Direct Z-scheme MoSe₂/TiO₂ heterostructure with improved piezoelectric and piezo-photocatalytic performance

J Colloid Interface Sci. 2022 Sep 15:622:637-651. doi: 10.1016/j.jcis.2022.04.139. Epub 2022 Apr 29.

Authors

Qing Han¹, Shiwen Du², Yumin Wang¹, Ziwu Han¹, Hongjing Li¹, Hu Xu³, Pengfei Fang⁴

Affiliations

¹ School of Physics and Technology, Key Laboratory of Nuclear Solid State Physics Hubei Province, Wuhan University, Wuhan 430072, China.
² School of Physics and Technology, Key Laboratory of Nuclear Solid State Physics Hubei Province, Wuhan University, Wuhan 430072, China; State Key Laboratory of Catalysis, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian 116023, China.
³ Department of Physics, Southern University of Science and Technology, Shenzhen 518055, China.
⁴ School of Physics and Technology, Key Laboratory of Nuclear Solid State Physics Hubei Province, Wuhan University, Wuhan 430072, China. Electronic address: fangpf@whu.edu.cn.

PMID: 35533479
DOI: 10.1016/j.jcis.2022.04.139

Abstract

Nano-semiconductor materials coupled with piezoelectric effect have received extensive attention due to their wide application in catalysis. In this work, few-layered MoSe₂ nanosheets were grown vertically on TiO₂ nanorods (TNr) to synthesize a direct Z-scheme heterojunction, exhibiting efficient piezocatalytic and piezo-photocatalytic performance. The MoSe₂/TNr heterostructure exhibited superior piezoelectric degradation efficiency, successfully removing over 98% of RhB within 360 s under continuous magnetic stirring in dark. Compared with piezocatalysis, the piezo-photocatalytic system possessed higher degradation efficiency and cycle stability. Furthermore, a piezo-photoelectric synergistic effect of nanocomposites was observed by current outputs. Under stirring conditions, the current density of depleted MoSe₂/TNr and MoSe₂ nanosheets were respectively 6.3 μA/cm² and 5.5 μA/cm². When light and stirring were applied, the MoSe₂/TNr current density increased twice to 13.2 μA/cm², while the MoSe₂ nanosheets didn't exhibit improvement. Through the direct Z-scheme heterojunction of MoSe₂/TNr, photoexcitation and piezoelectric polarization work together to effectively replenish carriers under light irradiation, and then rapidly separate free charges through piezopotential. This work broadens the application prospects of piezocatalysis and piezo-photocatalysis in renewable energy harvesting and water purification.

Keywords: Direct Z-scheme heterojunction; MoSe(2) nanosheets; Piezo-photocatalysis; Piezoelectric effect.