微結構優化與 GO 耦合大幅提高(BiO)₂CO₃可見光催化性能

董帆, 李秋燕, 何詠基, 吳忠標

Research output: Contribution to journalArticles

7 Citations (Scopus)

Abstract

以檸檬酸鉍、無水碳酸鈉和氧化石墨烯(GO)為原料,採用一步水熱法合成(BiO)₂CO₃與GO複合的新型三維(3D)分級結構光催化劑(BOC-GO)。通過X射線衍射、掃描電子顯微鏡、透射電子顯微鏡、傅裡葉紅外光譜、拉曼光譜、X射線光電子能譜、表面積測定、紫外可見漫反射光譜和螢光光譜對樣品進行表徵分析。結果表明,(BiO)₂CO₃微球分散在GO薄膜上,形成了新穎的3D分級結構。這種特殊的新結構作為光催化劑,在可見光照射下對ppb級NO(1ppb=1 μg/m³)表現出了大幅增強的可見光催化活性和良好的光化學穩定性,遠高於(BiO)₂CO₃以及其他可見光催化劑。BOC-GO優異的活性可歸因於3D分級結構與GO的耦合。一方面(BiO)₂CO₃微球特殊的3D分層結構,既能誘導入射光產生多次的散射和反射效應,增加對可見光的捕獲利用,也能促進光催化過程中反應物和中間產物的快速轉移和運輸,為催化劑提供更多的活性位點;另一方面歸因於GO自身優越的電子遷移能力,能夠將(BiO)₂CO₃的導帶電子迅速轉移和運輸,從而促進(BiO)₂CO₃上電子-空穴對的有效分離。將光催化劑自身微結構優化與GO耦合是一種大幅提高可見光催化性能的新方法。

The novel 3D hierarchical structure of (BiO)₂CO₃ coupled with graphene oxide (GO) were fabricated by a one-pot hydrothermal method using bismuth citrate, sodium carbonate and GO as precursors. The as-prepared samples were systematically characterized by XRD, SEM, TEM, FT-IR, Raman, BET, UV-vis DRS and PL. The results indicated that (BiO)₂CO₃ hierarchical microspheres were dispersed on GO films and novel 3D hierarchical structure was formed. The novel 3D structure exhibited outstanding photocatalytic activity and photochemical stability towards degradation of NO at μg/m³-level under visible light irradiation, much higher than that of (BiO)₂CO₃ and other well-known visible light photocatalysts. The outstanding activity can be ascribed to the special 3D hierarchical architecture of (BiO)₂CO₃ and superior charge carrier mobility of GO. On one hand, the 3D hierarchical architecture can capture more visible light due to the multiple surface scattering and reflecting effects. Also, the hierarchical architecture can function as transport path for reactants and intermediate products and provide more active sites in photocatalsis. On the other hand, the superior charge carrier mobility of GO could facilitate the transfer of exited electrons from conduction band of (BiO)₂CO₃ to GO, effectively preventing the recombination of electron-hole pairs. Combination of micro-structural optimization and GO coupling is a novel approach for efficiently promoting the visible light photocatalysis. This work could provide a new perspective for controlled synthesis of GO-based photocatalytic materials and mechanism understanding and also new materials for high-performance degradation of environmental pollutants and solar energy conversion. Copyright © 2015 《中國科學》雜誌社.
Original languageChinese
Pages (from-to)1915-1923
Journal科學通報
Volume60
Issue number20
DOIs
Publication statusPublished - Jul 2015

Citation

董帆、李秋燕、何詠基和吳忠標(2015):微結構優化與 GO 耦合大幅提高(BiO)₂CO₃可見光催化性能,《科學通報》,60(20),頁1915-1923。

Keywords

  • 水熱法
  • (BiO)₂CO₃
  • 石墨烯
  • 3D 分級結構
  • 可見光催化
  • 電子-空穴分離
  • Alt. title: The mechanism of enhanced visible light photocatalysis with micro-structurally optimized and graphene oxide coupled (BiO)₂CO₃
  • Hydrothermal synthesis
  • Graphene
  • 3D hierarchical structure
  • Visible light photocatalysis
  • Electron-hole separation