Design and in-situ construct BiOI/Bi/TiO₂ photocatalysts with metal-mediated heterostructures employing oxygen vacancies in TiO₂ nanosheets

TY - JOUR

T1 - Design and in-situ construct BiOI/Bi/TiO2 photocatalysts with metal-mediated heterostructures employing oxygen vacancies in TiO2 nanosheets

AU - Zhang, Chenchen

AU - Chen, Wenbin

AU - Hu, Dairong

AU - Xie, Hanjie

AU - Song, Yibing

AU - Luo, Binbin

AU - Fang, Yiwen

AU - Gao, Wenhua

AU - Zhong, Ziyi

N1 - Publisher Copyright: © 2020 Institute of Process Engineering, Chinese Academy of Sciences

PY - 2022/8

Y1 - 2022/8

N2 - The conventional p-n heterojunction photocatalysts suffer from the incompatibility between the interfacial charge transfer efficiency and the redox ability of charge carriers. To optimize the interfacial charge transfer of the conventional BiOI/TiO2 p-n photocatalyst, we synthesized the BiOI/Bi/TiO2 ternary photocatalyst with sandwiched metallic bismuth (Bi0) by the oxygen-vacancy assisted method. The DFT calculation and structural characterizations confirmed the reaction of the electron-rich oxygen vacancies in the 2D-TiO2 nanosheets (TiO2-NS) with the adsorbed BiO+ species. This reaction broke the Bi–O bonds to form Bi0 nanoparticles in-situ at the interface but still maintained the p-n heterojunction well. The NO-TPD and XRD analyses for samples correlated the Bi0 formation with the oxygen vacancy concentrations well. The sandwiched Bi0 functioned as an electronic transfer mediator like that in the Z-scheme heterostructure. Comparing with 0.20 BiOI/TiO2-NP (NP, Nanoparticles), 0.20 BiOI/Bi/TiO2-NS-a (NS, Nanosheet) showed a much improved catalytic performance, i.e., duplicated apparent quantum yield (AQY) and triplicated reaction rate constant (k). Also, the formation mechanism and the reaction mechanism were investigated in detail. This work provides a new strategy for the improving of the conventional p-n photocatalysts and new insights into the nature of the photocatalysis.

AB - The conventional p-n heterojunction photocatalysts suffer from the incompatibility between the interfacial charge transfer efficiency and the redox ability of charge carriers. To optimize the interfacial charge transfer of the conventional BiOI/TiO2 p-n photocatalyst, we synthesized the BiOI/Bi/TiO2 ternary photocatalyst with sandwiched metallic bismuth (Bi0) by the oxygen-vacancy assisted method. The DFT calculation and structural characterizations confirmed the reaction of the electron-rich oxygen vacancies in the 2D-TiO2 nanosheets (TiO2-NS) with the adsorbed BiO+ species. This reaction broke the Bi–O bonds to form Bi0 nanoparticles in-situ at the interface but still maintained the p-n heterojunction well. The NO-TPD and XRD analyses for samples correlated the Bi0 formation with the oxygen vacancy concentrations well. The sandwiched Bi0 functioned as an electronic transfer mediator like that in the Z-scheme heterostructure. Comparing with 0.20 BiOI/TiO2-NP (NP, Nanoparticles), 0.20 BiOI/Bi/TiO2-NS-a (NS, Nanosheet) showed a much improved catalytic performance, i.e., duplicated apparent quantum yield (AQY) and triplicated reaction rate constant (k). Also, the formation mechanism and the reaction mechanism were investigated in detail. This work provides a new strategy for the improving of the conventional p-n photocatalysts and new insights into the nature of the photocatalysis.

KW - Metallic bismuth

KW - Oxygen vacancy

KW - Photocatalysis

KW - Sandwiched heterostructure

KW - TiO nanosheets

UR - http://www.scopus.com/inward/record.url?scp=85100751529&partnerID=8YFLogxK

U2 - 10.1016/j.gee.2020.11.013

DO - 10.1016/j.gee.2020.11.013

M3 - 文章

AN - SCOPUS:85100751529

SN - 2096-2797

VL - 7

SP - 680

EP - 690

JO - Green Energy and Environment

JF - Green Energy and Environment

IS - 4

ER -