Understanding the High Photocatalytic Activity of (B, Ag)-Codoped TiO2 under Solar-Light Irradiation with XPS, Solid-State NMR, and DFT Calculations
The origin of the exceptionally high activity of (B, Ag)-codoped TiO2 catalysts under solar-light irradiation has been investigated by XPS and 11B solid-state NMR spectroscopy in conjunction with density functional theory (DFT) calculations.XPS experimental results demonstrated that a portion of the dopant Ag (Ag3+) ions were implanted into the crystalline lattice of (B, Ag)-codoped TiO2 and were in close proximity to the interstitial B (Bint) sites, forming ”Bint-O-Ag” structural units.In situ XPS experiments were employed to follow the evolution of the chemical states of the B and Ag dopants during UV-vis irradiation.It was found that the ”Bint-O-Ag” units could trap the photoinduced electron to form a unique intermediate structure in the (B, Ag)-codoped TiO2 during the irradiation, which is responsible for the photoinduced shifts of the B 1s and Ag 3d peaks observed in the in situ XPS spectra.Solid-state NMR experiments including 11B triple-quantum and double-quantum magic angle spinning (MAS) NMR revealed that up to six different boron species were present in the catalysts and only the tricoordinated interstitial boron (T*) species was in dose proximity to the substitutional Ag species, leading to formation of ”T*-O-Ag” structural units.Furthermore, as demonstrated by DFT calculations, the ”T*-O-Ag” structural units were responsible for trapping the photoinduced electrons, which prolongs the life of the photoinduced charge carriers and eventually leads to a remarkable enhancement in the photocatalytic activity.All these unprecedented findings are expected to be crucial for understanding the roles of B and Ag dopants and their synergistic effect in numerous titaniamediated photocatalytic reactions.
Ningdong Feng Qiang Wang Anmin Zheng Zhengfeng Zhang Jie Fan Shang-Bin Liu Jean-paul Amoureux Feng Deng
State Key Laboratory of Magnetic Resonance and Atomic Molecular Physics,Wuhan Center for Magnetic Re Key Laboratory of Applied Chemistry of Zhejiang Province and Department of Chemistry,Zhejiang Univer Institute of Atomic and Molecular Sciences,Academia Sinica,P.O.Box 23-166,Taipei 10617,Taiwan UCCS (CNRS-8181),Batiment C7,ENSCL Lille-1 University,Villeneuve d”Ascq 59652,France
国内会议
苏州
英文
411-420
2014-10-26（万方平台首次上网日期，不代表论文的发表时间）