Engineering oxygen vacancy on rutile TiO2 for efficient electron-hole separation and high solar-driven photocatalytic hydrogen evolution

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  • ReceivedJan 2, 2018
  • AcceptedJan 28, 2018
  • PublishedFeb 13, 2018


Oxygen vacancy (VO) plays a vital role in semiconductor photocatalysis. Rutile TiO2 nanomaterials with controllable contents of VO (0–2.18%) are fabricated via an in-situ solid-state chemical reduction strategy, with color from white to black. The bandgap of the resultant rutile TiO2 is reduced from 3.0 to 2.56 eV, indicating the enhanced visible light absorption. The resultant rutile TiO2 with optimal contents of VO (~2.07%) exhibits a high solar-driven photocatalytic hydrogen production rate of 734 μmol h−1, which is about four times as high as that of the pristine one (185 μmol h−1). The presence of VO elevates the apparent Fermi level of rutile TiO2 and promotes the efficient electron-hole separation obviously, which favor the escape of photogenerated electrons and prolong the life-time (7.6×103 ns) of photogenerated charge carriers, confirmed by scanning Kelvin probe microscopy, surface photovoltage spectroscopy and transient-state fluorescence. VO-mediated efficient photogenerated electron-hole separation strategy may provide new insight for fabricating other high-performance semiconductor oxide photocatalysts.

Funded by

the Key Program Projects of the National Natural Science Foundation of China(21631004)

the National Natural Science Foundation of China(51672073)


This work was supported by the Key Program Projects of the National Natural Science Foundation of China (21631004) and the National Natural Science Foundation of China (51672073).

Interest statement

These authors declared no conflict of interest.

Contributions statement

Xiao F conducted the experiments; Zhou W, Zhao X and Fu H designed and engineered the work; Sun B, Li H, Qiao P and Ren L performed the characterization; Xiao F wrote the paper with support from Zhou W, Zhao X and Fu H. All authors contributed to the general discussion.

Author information

Fang Xiao received her BSc degree in 2015 from Datong University, China. Her research interests are focused on rutile TiO2 nanomaterials for photocatalysis.

Wei Zhou received his PhD degree in 2009 from Jilin University, China. Afterwards, he joined Prof. Honggang Fu’s group at Heilongjiang University, and became a full professor in 2015. His research interests include mesoporous materials, semiconductor nanomaterials for solar energy conversion, photocatalysis, and their photothermal and photoelectrochemical performance.

Xiaojun Zhao received his BSc degree in 1982 from Tianjin Normal University, China. He received his MSc degree in 2001 and PhD degree in 2004 from Nankai University, China. Currently, he is a full professor at Tianjin Normal University. His research interests focus on inorganic-organic hybrid functional material.

Honggang Fu received his BSc degree in 1984 and MSc degree in 1987 from Jilin University, China. Then, he joined Heilongjiang University as an assistant professor. In 1999, he received his PhD degree from Harbin Institute of Technology, China. He became a full professor in 2000. Currently, he is also Cheung Kong Scholar Professor. His interests focus on oxide-based semiconductor nanomaterials for solar energy conversion and photocatalysis, and crystalline carbon-based nanomaterials for energy conversion and storage.


Supplementary information

Supplementary data are available in the online version of the paper.


[1] Lin L, Zhou W, Gao R, et al. Low-temperature hydrogen production from water and methanol using Pt/α-MoC catalysts. Nature, 2017, 544: 80-83 CrossRef PubMed ADS Google Scholar

[2] Yuan YJ, Yu ZT, Chen DQ, et al. Metal-complex chromophores for solar hydrogen generation. Chem Soc Rev, 2017, 46: 603-631 CrossRef PubMed Google Scholar

[3] Yang L, Li X, Zhang G, et al. Combining photocatalytic hydrogen generation and capsule storage in graphene based sandwich structures. Nat Commun, 2017, 8: 16049 CrossRef PubMed ADS Google Scholar

[4] Wang Q, Hisatomi T, Jia Q, et al. Scalable water splitting on particulate photocatalyst sheets with a solar-to-hydrogen energy conversion efficiency exceeding 1%. Nat Mater, 2016, 15: 611-615 CrossRef PubMed ADS Google Scholar

[5] Fujishima A, Honda K. Electrochemical photolysis of water at a semiconductor electrode. Nature, 1972, 238: 37-38 CrossRef ADS Google Scholar

[6] Fang WH, Zhang L, Zhang J. A 3.6 nm Ti52–oxo nanocluster with precise atomic structure. J Am Chem Soc, 2016, 138: 7480-7483 CrossRef PubMed Google Scholar

[7] Elbanna O, Fujitsuka M, Majima T. g-C3N4/TiO2 mesocrystals composite for H2 evolution under visible-light irradiation and its charge carrier dynamics. ACS Appl Mater Interfaces, 2017, 9: 34844-34854 CrossRef Google Scholar

[8] Hussain H, Tocci G, Woolcot T, et al. Structure of a model TiO2 photocatalytic interface. Nat Mater, 2017, 16: 461-466 CrossRef PubMed ADS arXiv Google Scholar

[9] Ren XN, Hu ZY, Jin J, et al. Cocatalyzing Pt/PtO phase-junction nanodots on hierarchically porous TiO2 for highly enhanced photocatalytic hydrogen production. ACS Appl Mater Interfaces, 2017, 9: 29687-29698 CrossRef Google Scholar

[10] Selcuk S, Selloni A. Facet-dependent trapping and dynamics of excess electrons at anatase TiO2 surfaces and aqueous interfaces. Nat Mater, 2016, 15: 1107-1112 CrossRef PubMed ADS Google Scholar

[11] Sun Z, Liao T, Kou L. Strategies for designing metal oxide nanostructures. Sci China Mater, 2017, 60: 1-24 CrossRef Google Scholar

[12] Niu M, Zhang J, Cao D. I, N-codoping modification of TiO2 for enhanced photoelectrochemical H2O splitting in visible-light region. J Phys Chem C, 2017, 121: 26202-26208 CrossRef Google Scholar

[13] Qian L, Yu P, Zeng J, et al. Large-scale functionalization of biomedical porous titanium scaffolds surface with TiO2 nanostructures. Sci China Mater, 2018, 61: 557-564 CrossRef Google Scholar

[14] Guo L, Fei C, Zhang R, et al. Impact of sol aging on TiO2 compact layer and photovoltaic performance of perovskite solar cell. Sci China Mater, 2016, 59: 710-718 CrossRef Google Scholar

[15] Li R, Weng Y, Zhou X, et al. Achieving overall water splitting using titanium dioxide-based photocatalysts of different phases. Energy Environ Sci, 2015, 8: 2377-2382 CrossRef Google Scholar

[16] Yu XY, Wu HB, Yu L, et al. Rutile TiO2 submicroboxes with superior lithium storage properties. Angew Chem Int Ed, 2015, 54: 4001-4004 CrossRef PubMed Google Scholar

[17] Wu T, Kang X, Kadi MW, et al. Enhanced photocatalytic hydrogen generation of mesoporous rutile TiO2 single crystal with wholly exposed {111} facets. Chin J Catal, 2015, 36: 2103-2108 CrossRef Google Scholar

[18] Maeda K, Ishimaki K, Okazaki M, et al. Cobalt oxide nanoclusters on rutile titania as bifunctional units for water oxidation catalysis and visible light absorption: understanding the structure–activity relationship. ACS Appl Mater Interfaces, 2017, 9: 6114-6122 CrossRef Google Scholar

[19] Nguyen-Phan TD, Luo S, Vovchok D, et al. Visible light-driven H2 production over highly dispersed ruthenia on rutile TiO2 nano-rods. ACS Catal, 2016, 6: 407-417 CrossRef Google Scholar

[20] Li L, Yan J, Wang T, et al. Sub-10 nm rutile titanium dioxide nanoparticles for efficient visible-light-driven photocatalytic hydrogen production. Nat Commun, 2015, 6: 5881 CrossRef PubMed ADS Google Scholar

[21] Kim W, Tachikawa T, Moon G, et al. Molecular-level understanding of the photocatalytic activity difference between anatase and rutile nanoparticles. Angew Chem Int Ed, 2014, 53: 14036-14041 CrossRef PubMed Google Scholar

[22] Lun Pang C, Lindsay R, Thornton G. Chemical reactions on rutile TiO2 (110). Chem Soc Rev, 2008, 37: 2328-2353 CrossRef PubMed Google Scholar

[23] Yang Y, Liu G, Irvine JTS, et al. Enhanced photocatalytic H2 production in core-shell engineered rutile TiO2. Adv Mater, 2016, 28: 5850-5856 CrossRef PubMed Google Scholar

[24] Zhao Z, Zhang X, Zhang G, et al. Effect of defects on photocatalytic activity of rutile TiO2 nanorods. Nano Res, 2015, 8: 4061-4071 CrossRef Google Scholar

[25] Schaub R, Thostrup P, Lopez N, et al. Oxygen vacancies as active sites for water dissociation on rutile TiO2 (110). Phys Rev Lett, 2001, 87: 266104 CrossRef PubMed ADS Google Scholar

[26] Chen X, Liu L, Yu PY, et al. Increasing solar absorption for photocatalysis with black hydrogenated titanium dioxide nanocrystals. Science, 2011, 331: 746-750 CrossRef PubMed ADS Google Scholar

[27] Zhou W, Li W, Wang JQ, et al. Ordered mesoporous black TiO2 as highly efficient hydrogen evolution photocatalyst. J Am Chem Soc, 2014, 136: 9280-9283 CrossRef PubMed Google Scholar

[28] Tan H, Zhao Z, Niu M, et al. A facile and versatile method for preparation of colored TiO2 with enhanced solar-driven photocatalytic activity. Nanoscale, 2014, 6: 10216-10223 CrossRef PubMed ADS Google Scholar

[29] Hu W, Zhou W, Zhang K, et al. Facile strategy for controllable synthesis of stable mesoporous black TiO2 hollow spheres with efficient solar-driven photocatalytic hydrogen evolution. J Mater Chem A, 2016, 4: 7495-7502 CrossRef Google Scholar

[30] Chen X, Liu L, Huang F. Black titanium dioxide (TiO2) nanomaterials. Chem Soc Rev, 2015, 44: 1861-1885 CrossRef PubMed Google Scholar

[31] Cushing SK, Meng F, Zhang J, et al. Effects of defects on photocatalytic activity of hydrogen-treated titanium oxide nanobelts. ACS Catal, 2017, 7: 1742-1748 CrossRef Google Scholar

[32] Henkel B, Neubert T, Zabel S, et al. Photocatalytic properties of titania thin films prepared by sputtering versus evaporation and aging of induced oxygen vacancy defects. Appl Catal B-Environ, 2016, 180: 362-371 CrossRef Google Scholar

[33] Weng X, Zeng Q, Zhang Y, et al. Facile approach for the syntheses of ultrafine TiO2 nanocrystallites with defects and C heterojunction for photocatalytic water splitting. ACS Sustain Chem Eng, 2016, 4: 4314-4320 CrossRef Google Scholar

[34] Zhang Y, Ding Z, Foster CW, et al. Oxygen vacancies evoked blue TiO2(B) nanobelts with efficiency enhancement in sodium storage behaviors. Adv Funct Mater, 2017, 27: 1700856 CrossRef Google Scholar

[35] Song H, Li C, Lou Z, et al. Effective formation of oxygen vacancies in black TiO2 nanostructures with efficient solar-driven water splitting. ACS Sustain Chem Eng, 2017, 5: 8982-8987 CrossRef Google Scholar

[36] Vásquez GC, Karazhanov SZ, Maestre D, et al. Oxygen vacancy related distortions in rutile TiO2 nanoparticles: A combined experimental and theoretical study. Phys Rev B, 2016, 94: 235209 CrossRef ADS Google Scholar

[37] Zhang Y, Harris CX, Wallenmeyer P, et al. Asymmetric lattice vibrational characteristics of rutile TiO2 as revealed by laser power dependent raman spectroscopy. J Phys Chem C, 2013, 117: 24015-24022 CrossRef Google Scholar

[38] Vásquez GC, Maestre D, Cremades A, et al. Assessment of the Cr doping and size effects on the Raman-active modes of rutile TiO2 by UV/visible polarized Raman spectroscopy. J Raman Spectrosc, 2017, 48: 847-854 CrossRef ADS Google Scholar

[39] Wu Y, Jiang Y, Shi J, et al. Multichannel porous TiO2 hollow nanofibers with rich oxygen vacancies and high grain boundary density enabling superior sodium storage performance. Small, 2017, 13: 1700129 CrossRef PubMed Google Scholar

[40] Naldoni A, Allieta M, Santangelo S, et al. Effect of nature and location of defects on bandgap narrowing in black TiO2 nanoparticles. J Am Chem Soc, 2012, 134: 7600-7603 CrossRef PubMed Google Scholar

[41] Zhou W, Sun F, Pan K, et al. Well-ordered large-pore mesoporous anatase TiO2 with remarkably high thermal stability and improved crystallinity: preparation, characterization, and photocatalytic performance. Adv Funct Mater, 2011, 21: 1922-1930 CrossRef Google Scholar

[42] Gao S, Sun Z, Liu W, et al. Atomic layer confined vacancies for atomic-level insights into carbon dioxide electroreduction. Nat Commun, 2017, 8: 14503 CrossRef PubMed ADS Google Scholar

[43] Liao X, Zhang Y, Hill M, et al. Highly efficient Ni/CeO2 catalyst for the liquid phase hydrogenation of maleic anhydride. Appl Catal A-General, 2014, 488: 256-264 CrossRef Google Scholar

[44] Tan S, Xing Z, Zhang J, et al. Ti3+-TiO2/g-C3N4 mesostructured nanosheets heterojunctions as efficient visible-light-driven photocatalysts. J Catal, 2018, 357: 90-99 CrossRef Google Scholar

[45] Liu J, Liu Y, Liu N, et al. Metal-free efficient photocatalyst for stable visible water splitting via a two-electron pathway. Science, 2015, 347: 970-974 CrossRef PubMed ADS Google Scholar

[46] Kronik L, Shapira Y. Surface photovoltage phenomena: theory, experiment, and applications. Surf Sci Rep, 1999, 37: 1-206 CrossRef ADS Google Scholar

[47] Hu Y, Pecunia V, Jiang L, et al. Scanning Kelvin probe microscopy investigation of the role of minority carriers on the switching characteristics of organic field-effect transistors. Adv Mater, 2016, 28: 4713-4719 CrossRef PubMed Google Scholar

[48] Zhang H, Wang G, Chen D, et al. Tuning photoelectrochemical performances of Ag−TiO2 nanocomposites via reduction/oxidation of Ag. Chem Mater, 2008, 20: 6543-6549 CrossRef Google Scholar

[49] Mao C, Zuo F, Hou Y, et al. In situ preparation of a Ti3+ self-doped TiO2 film with enhanced activity as photoanode by N2H4 reduction. Angew Chem Int Ed, 2014, 53: 10485-10489 CrossRef PubMed Google Scholar

  • Figure 1

    Typical XRD patterns (a) and Raman spectra (b) of pristine rutile TiO2 (i) and hydrogenated rutile TiO2 under 250°C (ii), 300°C (iii), and 350°C (iv), respectively.

  • Figure 2

    SEM (a), TEM (b), HRTEM images (c) and the corresponding selected-area electron diffraction pattern (d) of the hydrogenated rutile TiO2 (300°C).

  • Figure 3

    The UV/vis absorption spectra (a), the corresponding optical bandgaps (b), N2 adsorption-desorption isotherms (c), XPS of valence band spectra (d), O 1s (e) and Ti 2p (f) of the pristine rutile TiO2 (i) and the hydrogenated rutile TiO2 under 250°C (ii), 300°C (iii), and 350°C (iv), respectively. The inset of (a) is the digital photos of sample i–iv.

  • Figure 4

    (a) Photocatalytic hydrogen evolution rates, (b) cycling tests of photocatalytic hydrogen generation under AM 1.5 irradiation, (c) the single-wavelength photocatalytic hydrogen evolution rates, (d) transient-state fluorescence spectrum, (e) surface photovoltage spectroscopy, (f) scanning Kelvin probe maps of pristine rutile TiO2 (i) and hydrogenated rutile TiO2 under 250°C (ii), 300°C (iii), and 350°C (iv), respectively. The inset of (c) enlarges the AQE of single-wavelength light at 420 and 520 nm.

  • Figure 5

    Photoelectrochemical properties of the pristine rutile TiO2 (sample i) and the hydrogenated rutile TiO2 (sample iii). (a) Linear sweeps voltammograms in the dark and under AM 1.5 irradiation, (b) the chronoamperometry, (c) the Nyquist plots of electrochemical impedance in the dark and under AM 1.5 irradiation, and (d) the Mott-Schottky plots.

  • Figure 6

    Schematic illustration of oxygen vacancy-mediated efficient photogenerated electron-hole separation in hydrogenated rutile TiO2 photocatalytic hydrogen production.

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