Interface engineering of Mn3O4/Co3O4 S-scheme heterojunctions to enhance the photothermal catalytic degradation of toluene

Jungang Zhao; Caiting Li; Qi Yu; Youcai Zhu; Xuan Liu; Shanhong Li; Caixia Liang; Ying Zhang; Le Huang; Kuang Yang; Ziang Zhang; Yunbo Zhai

doi:10.1016/j.jhazmat.2023.131249

Interface engineering of Mn₃O₄/Co₃O₄ S-scheme heterojunctions to enhance the photothermal catalytic degradation of toluene

J Hazard Mater. 2023 Jun 15:452:131249. doi: 10.1016/j.jhazmat.2023.131249. Epub 2023 Mar 22.

Authors

Jungang Zhao¹, Caiting Li², Qi Yu¹, Youcai Zhu¹, Xuan Liu¹, Shanhong Li¹, Caixia Liang¹, Ying Zhang¹, Le Huang¹, Kuang Yang¹, Ziang Zhang¹, Yunbo Zhai¹

Affiliations

¹ College of Environmental Science and Engineering, Hunan University, Changsha 410082, PR China; Key Laboratory of Environmental Biology and Pollution Control, Hunan University, Ministry of Education, Changsha 410082, PR China.
² College of Environmental Science and Engineering, Hunan University, Changsha 410082, PR China; Key Laboratory of Environmental Biology and Pollution Control, Hunan University, Ministry of Education, Changsha 410082, PR China. Electronic address: ctli@hnu.edu.cn.

PMID: 36966624
DOI: 10.1016/j.jhazmat.2023.131249

Abstract

Transition metal oxides have high photothermal conversion capacity and excellent thermal catalytic activity, and their photothermal catalytic ability can be further improved by reasonably inducing the photoelectric effect of semiconductors. Herein, Mn₃O₄/Co₃O₄ composites with S-scheme heterojunctions were fabricated for photothermal catalytic degradation of toluene under ultraviolet-visible (UV-Vis) light irradiation. The distinct hetero-interface of Mn₃O₄/Co₃O₄ effectively increases the specific surface area and promotes the formation of oxygen vacancies, thus facilitating the generation of reactive oxygen species and migration of surface lattice oxygen. Theoretical calculations and photoelectrochemical characterization demonstrate the existence of a built-in electric field and energy band bending at the interface of Mn₃O₄/Co₃O₄, which optimizes the photogenerated carriers' transfer path and retains a higher redox potential. Under UV-Vis light irradiation, the rapid transfer of electrons between interfaces promotes the generation of more reactive radicals, and the Mn₃O₄/Co₃O₄ shows a substantial improvement in the removal efficiency of toluene (74.7%) compared to single metal oxides (53.3% and 47.5%). Moreover, the possible photothermal catalytic reaction pathways of toluene over Mn₃O₄/Co₃O₄ were also investigated by in situ DRIFTS. The present work offers valuable guidance toward the design and fabrication of efficient narrow-band semiconductor heterojunction photothermal catalysts and provides deeper insights into the mechanism of photothermal catalytic degradation of toluene.

Keywords: DFT calculations; Interfacial effect; Photothermal catalysis; S-scheme heterojunction; Toluene.