Enhancing photoactivity for hydrogen generation by electron tunneling via flip-flop hopping over Möbius strip-like RGO

作者：Zhen Li; Bin Tian; Wenlong Zhen; Wenyan Zhang; Xuqiang Zhang; Yuqi Wu; Gongxuan Lu

来源：Applied Catalysis B: Environmental , 2017, 219: 501-510.

• Möbius strip-like RGO
• Rashba spin-orbit coupling
• Flip-flop electron tunneling
• Hydrogen evolution reaction

In this work, the Möbius strip-like reduced graphene oxide (RGO) was fabricated via I3− and I5− clusters, which offered a route for electron tunneling over RGO. This flip-flop electron tunneling took place via strong Rashba spin-orbit coupling between polyiodides and C atoms of RGO by the active electrons of polyiodides living in the p orbitals and it could bridge the easier charge transfer route between far-located carbon atoms at the edges of RGO through the polyiodides. This tunneling also restrained effectively the anisotropy of the electron transfer over RGO surface, achieving the rapid and efficient electron transfer over the surface of the RGO, resulting in remarkable increase of RGO conductivity and enhancing the lifetime of photogenerated charges. With the help of these properties, the obtained I-RGO/Ag photocatalyst presented a high H2 generation activity under visible light irradiation. 318.8 μmol H2 was evolved over I-RGO/Ag photocatalyst in 3 h, about 3.3 time higher than that of un-iodine RGO/Ag. In addition, no remarkable decay of H2 evolution activity was observed in 1080 min reaction. The highest apparent quantum efficiencie (AQE) value of 28.8% was achieved at 430 nm.
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