Chinese Journal of Catalysis ›› 2022, Vol. 43 ›› Issue (4): 1074-1083.DOI: 10.1016/S1872-2067(21)63969-4

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Novel core-shell Ag@AgSex nanoparticle co-catalyst: In situ surface selenization for efficient photocatalytic H2 production of TiO2

Wei Zhonga, Jiachao Xua, Ping Wanga, Bicheng Zhub,#(), Jiajie Fanc, Huogen Yua,b,*()   

  1. aState Key Laboratory of Silicate Materials for Architectures and School of Chemistry, Chemical Engineering and Life Sciences, Wuhan University of Technology, Wuhan 430070, Hubei, China
    bLaboratory of Solar Fuel, Faculty of Materials Science and Chemistry, China University of Geosciences, Wuhan 430074, Hubei, China
    cSchool of Materials Science and Engineering, Zhengzhou University, Zhengzhou 450002, Henan, China
  • Received:2021-09-22 Accepted:2021-09-22 Online:2022-03-05 Published:2022-03-01
  • Contact: Bicheng Zhu, Huogen Yu
  • Supported by:
    National Natural Science Foundation of China(51872221);National Natural Science Foundation of China(22075220);National Natural Science Foundation of China(21905219);National Natural Science Foundation of China(52073263);111 Project(B18038)

Abstract:

Effective charge separation and rapid interfacial H2 production are imperative for the construction of efficient photocatalysts. Compared to Pt, the metallic Ag co-catalyst with its strong electron-trapping ability and excellent electronic conductivity typically exhibits an extremely limited photocatalytic H2-evolution rate owing to its sluggish interfacial H2-generation reaction. In this study, amorphous AgSex was incorporated in situ onto metallic Ag as a novel and excellent H2-evolution active site to boost the interfacial H2-generation rate of Ag nanoparticles in a TiO2/Ag system. Core-shell Ag@AgSex nanoparticle-modified TiO2 photocatalysts were prepared via a two-step pathway involving the photodeposition of metallic Ag and the selective surface selenization of metallic Ag to yield amorphous AgSex shells. The as-prepared TiO2/Ag@AgSex (20 μL) photocatalyst exhibited an excellent H2-production performance of 853.0 μmol h-1g-1, prominently outperforming the TiO2 and TiO2/Ag samples by factors of 11.6 and 2.4, respectively. Experimental investigations and DFT calculations revealed that the enhanced H2-generation activity of the TiO2/Ag@AgSex photocatalyst could be accounted by synergistic interactions of the Ag@AgSex co-catalyst. Essentially, the metallic Ag core could quickly capture and transport the photoinduced electrons from TiO2 to the amorphous AgSex shell, whereas the amorphous AgSex shell provided large active sites for boosting the interfacial H2 evolution. This study offers a facile route for the construction of novel core-shell co-catalysts for sustainable H2 evolution.

Key words: Photocatalytic H2 evolution, Co-catalyst, Surface selenization, Ag@AgSex, Synergistic effect