Origin of the Adsorption-State-Dependent Photoactivity of Methanol on TiO2(110)

Dong，Shanshan1,5; Hu，Jinyuan2; Xia，Shucai1,5; Wang，Binli1,5; Wang，Zhiqiang3; Wang，Tianjun1,5; Chen，Wei1,5; Ren，Zefeng1; Fan，Hongjun1; Dai，Dongxu1; Cheng，Jun2; Yang，Xueming1,4; Zhou，Chuanyao1,5

2021

10.1021/acscatal.0c03930

ACS Catalysis   影响因子和分区

2155-5435

2155-5435

Methanol has long been used as a hole scavenger in photocatalysis to improve charge separation. Although the prototypical methanol/TiO2(110) system shows salient adsorption-state-dependent photoactivity, the underlying reason still remains unclear. Through surface-sensitive ultraviolet photoelectron spectroscopy measurements, we found that methoxy anions and methanol strengthen and flatten the originally upward band bending of TiO2(110), respectively. Intensified upward band bending leads to charge separation in the depletion region and hole accumulation at the surface. Furthermore, density functional theory calculations show that the hole transfer at the CH3O-/TiO2 interface is thermodynamically allowed and that on CH3OH/TiO2 is unfavorable. The improved charge separation together with the allowed interfacial hole transfer is found to be responsible for the superior photoactivity of the methoxy anion over methanol on TiO2. These results reconcile the existing contradiction in the understanding of the charge transfer at the CH3O-/TiO2 interface based on the photoemission measured energy levels. Our work suggests that the redox potential level, rather than the vertical energy (for example, the HOMO of adsorbates) measured by spectroscopy, should be used to evaluate the possibility of the heterogeneous interfacial charge transfer.

hybrid functional interfacial charge transfer level alignment methanol redox free energy TiO2

SCI ; EI

英语

其他

National Natural Science Foundation of China[21973092,21573225,21688102] ; National Key Research and Development Program of China["2016YFA0200602","2018YFA0208703"] ; Strategic Pilot Science and Technology Project[XDB17000000] ; Youth Innovation Promotion Association[2017224] ; Instrument Developing Project of CAS[YZ201504] ; Natural Science Foundation of Shaanxi Province[2019JQ047]

Chemistry

Chemistry, Physical

WOS:000626844200013

AMER CHEMICAL SOC

20210910004792

Charge transfer ; Density functional theory ; Negative ions ; Oxide minerals ; Redox reactions ; Separation ; Titanium dioxide ; Ultraviolet photoelectron spectroscopy

Minerals:482.2 ; Chemical Reactions:802.2 ; Chemical Operations:802.3 ; Organic Compounds:804.1 ; Inorganic Compounds:804.2 ; Probability Theory:922.1

2-s2.0-85101695643

Scopus

1.State Key Laboratory of Molecular Reaction Dynamics,Dalian Institute of Chemical Physics,Chinese Academy of Science,Dalian, Liaoning,457 Zhongshan Road,116023,China
2.State Key Laboratory of Physical Chemistry of Solid Surfaces,IChEM,College of Chemistry and Chemical Engineering,Xiamen University,Xiamen,361005,China
3.School of Physics and Optoelectronic Engineering,Xidian University,Xi'an,710071,China
4.Department of Chemistry,Southern University of Science and Technology,Shenzhen, Guangdong,1088 Xueyuan Road,518055,China
5.University of Chinese Academy of Sciences,No.19A Yuquan Road,Shijingshan District,Beijing,100049,China

Dong，Shanshan,Hu，Jinyuan,Xia，Shucai,et al. Origin of the Adsorption-State-Dependent Photoactivity of Methanol on TiO2(110)[J]. ACS Catalysis,2021,11(5):2620-2630.

Dong，Shanshan.,Hu，Jinyuan.,Xia，Shucai.,Wang，Binli.,Wang，Zhiqiang.,...&Zhou，Chuanyao.(2021).Origin of the Adsorption-State-Dependent Photoactivity of Methanol on TiO2(110).ACS Catalysis,11(5),2620-2630.

Dong，Shanshan,et al."Origin of the Adsorption-State-Dependent Photoactivity of Methanol on TiO2(110)".ACS Catalysis 11.5(2021):2620-2630.