Construction of Ternary Bismuth‐Based Heterojunction by Using (BiO)2CO3 as Electron Bridge for Highly Efficient Degradation of Phenol

A Z-scheme Bi₂O₃/(BiO)₂CO₃/Bi₂MoO₆ heterojunction was fabricated. It exhibited excellent photocatalytic performances for phenol degradation, which was ascribed to the formation of a Z-scheme heterojunction, and the presence of (BiO)₂CO₃ that performed as an electron bridge to enable the migration distance of photogenerated electron from E_CB of Bi₂O₃ to E_VB of Bi₂MoO₆ to be shortened, greatly promoting the efficient separation of photogenerated electron-hole pairs.

Abstract

Inspired by nature, it has been considered an effective approach to design artificial photosynthetic system by fabricating Z-scheme photocatalysts to eliminate environmental issues and alleviate the global energy crisis. However, the development of low cost, environment-friendly, and high-efficient photocatalysts by utilizing solar energy still confronts huge challenge. Herein, we constructed a Bi₂O₃/(BiO)₂CO₃/Bi₂MoO₆ ternary heterojunction via a facile solvothermal method and calcination approach and used it as a photocatalyst for the degradation of phenol. The optimized Bi₂O₃/(BiO)₂CO₃/Bi₂MoO₆ heterojunction delivers a considerable activity for phenol photodegradation with an impressive removal efficiency of 98.8 % and about total organic carbon (TOC) of 68 % within 180 min under visible-light irradiation. The excellent photocatalytic activity was ascribed to the formation of a Z-scheme heterojunction, more importantly, the presence of (BiO)₂CO₃ as an electron bridge greatly shortens the migration distance of photogenerated electron from E_CB of Bi₂O₃ to E_VB of Bi₂MoO₆, thus prolonging the lifetime of photogenerated electrons, which is verified by trapping experiments, electron spin-resonance spectroscopy (ESR) results, and density functional theory (DFT) calculations. This work provides a potential strategy to fabricate highly efficient Bi-based Z-scheme photocatalysts with wide application prospects in solar-to-fuel conversion and environmental protection.

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