Selective Cocatalyst Decoration of Narrow-Bandgap Broken-Gap Heterojunction for Directional Charge Transfer and High Photocatalytic Properties

Jingwei Li; Hongli Fang; Mengqi Wu; Churong Ma; Ruqian Lian; San Ping Jiang; Mohamed Nawfal Ghazzal; Zebao Rui

doi:10.1002/smll.202300559

Selective Cocatalyst Decoration of Narrow-Bandgap Broken-Gap Heterojunction for Directional Charge Transfer and High Photocatalytic Properties

Small. 2023 Aug;19(35):e2300559. doi: 10.1002/smll.202300559. Epub 2023 May 1.

Authors

Jingwei Li^{1

2

3}, Hongli Fang¹, Mengqi Wu⁴, Churong Ma⁵, Ruqian Lian⁴, San Ping Jiang^{6

7}, Mohamed Nawfal Ghazzal², Zebao Rui¹

Affiliations

¹ School of Chemical Engineering and Technology, The Key Laboratory of Low-carbon Chemistry & Energy Conservation of Guangdong Province, Guangdong Engineering Technology Research Center for Platform Chemicals from Marine Biomass and Their Functionalization, Sun Yat-sen University, Zhuhai, 519082, China.
² Institut de Chimie Physique, UMR 8000 CNRS, Université Paris-Saclay, Orsay, 91405, France.
³ School of Chemistry and Chemical Engineering/Institute of Clean Energy and Materials/Guangzhou Key Laboratory for Clean Energy and Materials, Guangzhou University, Guangzhou, 510006, P. R. China.
⁴ Hebei Key Lab of Optic-Electronic Information and Materials, The College of Physics Science and Technology, Hebei University, Baoding, 071002, P. R. China.
⁵ Guangdong Provincial Key Laboratory of Optical Fiber Sensing and Communications, Institute of Photonics Technology, Jinan University, Guangzhou, 511443, China.
⁶ Foshan Xianhu Laboratory of the Advanced Energy Science and Technology Guangdong Laboratory, Foshan, Guangdong, 528216, China.
⁷ WA School of Mines: Minerals, Energy and Chemical Engineering, Curtin University, Perth, WA, 6102, Australia.

PMID: 37127880
DOI: 10.1002/smll.202300559

Abstract

Narrow-bandgap semiconductors are promising photocatalysts facing the challenges of low photoredox potentials and high carrier recombination. Here, a broken-gap heterojunction Bi/Bi₂ S₃ /Bi/MnO₂ /MnO_x , composed of narrow-bandgap semiconductors, is selectively decorated by Bi, MnO_x nanodots (NDs) to achieve robust photoredox ability. The Bi NDs insertion at the Bi₂ S₃ /MnO₂ interface induces a vertical carrier migration to realize sufficient photoredox potentials to produce O₂ ^•- and ^• OH active species. The surface decoration of Bi₂ S₃ /Bi/MnO₂ by Bi and MnO_x cocatalysts drives electrons and holes in opposite directions for optimal photogenerated charge separation. The selective cocatalysts decoration realizes synergistic surface and bulk phase carrier separation. Density functional theory (DFT) calculation suggests that Bi and MnOx NDs act as active sites enhancing the absorption and reactants activation. The decorated broken-gap heterojunction demonstrates excellent performance for full-light driving organic pollution degradation with great commercial application potential.

Keywords: broken-gap heterojunction; carrier separation; cocatalyst nanodots; narrow-bandgap semiconductors; organic pollution degradation.

Abstract

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