Microwave hydrothermal synthesis of lanthanum oxyfluoride nanorods for photocatalytic nitrogen fixation: Effect of Pr doping

Abstract

Photocatalytic fixation of nitrogen has been recognized as a green and promising strategy for ammonia synthesis under ambient conditions. However, the efficient reduction of nitrogen remains a challenge due to high activation energy of nitrogen and low utilization of solar energy. Herein, lanthanum oxyfluoride with different doping content of Pr³⁺ (LaOF:xPr³⁺) upconversion nanorods were synthesized by microwave hydrothermal method. Results indicated that the doping of Pr³⁺ generated considerable defects on the surface of LaOF which acted as the adsorption and activation center for nitrogen. Meanwhile, the Pr³⁺ ion narrowed the band gap and broadened the light response range of LaOF because LaOF:Pr³⁺ can upconvert visible light into ultraviolet light, which excite LaOF nanorods and improve the utilization of solar light. The doping amount of Pr³⁺ had critical effect on the photocatalytic nitrogen fixation performance which reached as high as 180 μmol·L⁻¹·h⁻¹ when the molar ratio of Pr³⁺ to LaOF was optimized to be 2%.

Keywords

LaOF / defect / upconversion / photocatalysis / nitrogen fixation

References

[1] Chen X, Li N, Kong Z, . Photocatalytic fixation of nitrogen to ammonia: State-of-the-art advancements and future prospects. Materials Horizons, 2018, 5(1): 9–27

[2] Xiao C, Zhang L, Wang K, . A new approach to enhance photocatalytic nitrogen fixation performance via phosphate-bridge: a case study of SiW₁₂/K-C₃N₄. Applied Catalysis B: Environmental, 2018, 239: 260–267

[3] Gao X, Wen Y, Qu D, . Interference effect of alcohol on Nessler’s reagent in photocatalytic nitrogen fixation. ACS Sustainable Chemistry & Engineering, 2018, 6(4): 5342–5348

[4] Wang K, Gu G, Hu S, . Molten salt assistant synthesis of three-dimensional cobalt doped graphitic carbon nitride for photocatalytic N₂ fixation: Experiment and DFT simulation analysis. Chemical Engineering Journal, 2019, 368: 896–904

[5] Lv C, Qian Y, Yan C, . Defect engineering metal-free polymeric carbon nitride electrocatalyst for effective nitrogen fixation under ambient conditions. Angewandte Chemie International Edition, 2018, 57(32): 10246–10250

[6] Fang Z, Yu G. Single atom catalyst towards ammonia synthesis at mild conditions. Science China Chemistry, 2018, 61(9): 1045–1046

[7] Bu T A, Hao Y C, Gao W Y, . Promoting photocatalytic nitrogen fixation with alkali metal cations and plasmonic nanocrystals. Nanoscale, 2019, 11(20): 10072–10079

[8] Wu S, Tan X, Liu K, . TiO₂ (B) nanotubes with ultrathin shell for highly efficient photocatalytic fixation of nitrogen. Catalysis Today, 2019, 335: 214–220

[9] Li X, He C, Zuo S, . Photocatalytic nitrogen fixation over fluoride/attapulgite nanocomposite: Effect of upconversion and fluorine vacancy. Solar Energy, 2019, 191: 251–262

[10] Xu H, Han X, Tan Q, . Crystal-chemistry insight into the photocatalytic activity of BiOCl_xBr_1−x nanoplate solid solutions. Frontiers of Materials Science, 2017, 11(2): 120–129

[11] Grzyb T, Weclawiak M, Pędziński T, . Synthesis, spectroscopic and structural studies on YOF, LaOF and GdOF nanocrystals doped with Eu³⁺, synthesized via stearic acid method. Optical Materials, 2013, 35(12): 2226–2233

[12] Fu Z, Liu B. Hydrothermal synthesis, energy transfer and luminescence enhancement of rhombohedral LaOF: Sm³⁺‒Eu³⁺ nanoparticles. Physica B: Condensed Matter, 2019, 574: 311653 (5 pages)

[13] He C, Ji H, Huang Z, . Preparation and photoluminescence properties of red-emitting phosphor ZnAl₂O₄:Eu³⁺ with an intense ⁵D₀ → ⁷F₂ transition. Materials Research Express, 2018, 5(2): 025501 (27 pages)

[14] Huang H, Li H, Wang Z, . Efficient near-infrared photocatalysts based on NaYF₄: Yb³⁺, Tm³⁺@NaYF₄: Yb³⁺, Nd³⁺@TiO₂ core@shell nanoparticles. Chemical Engineering Journal, 2019, 361: 1089–1097

[15] Naufal B, Jaseela P K, Periyat P. Direct sunlight active Sm³⁺ doped TiO₂ photocatalyst. Materials Science Forum, 2016, 855: 33–44

[16] Shen Z, Li H, Hao H, . Novel Tm³⁺ and Yb³⁺ co-doped bismuth tungstate up-conversion photocatalyst with greatly improved photocatalytic properties. Journal of Photochemistry and Photobiology A: Chemistry, 2019, 380: 111864–111872

[17] Stojadinović S, Tadić N, Radić N, . Effect of Tb³⁺ doping on the photocatalytic activity of TiO₂ coatings formed by plasma electrolytic oxidation of titanium. Surface and Coatings Technology, 2018, 337: 279–289

[18] Rakov N, Vieira S A, Guimarães R B, . Investigation of Eu³⁺ luminescence enhancement in LaOF powders codoped with Tb³⁺ and prepared by combustion synthesis. Journal of Alloys and Compounds, 2015, 618: 127–131

[19] Vinothkumar G, Rengaraj S, Arunkumar P, . Ionic radii and concentration dependency of RE³⁺ (Eu³⁺, Nd³⁺, Pr³⁺, and La³⁺)-doped Cerium Oxide nanoparticles for enhanced multienzyme-mimetic and hydroxyl radical scavenging activity. The Journal of Physical Chemistry C, 2019, 123(1): 541–553

[20] Li J, Jia L, Fang W, . Enhancement of activity of LaNi_0.7Cu_0.3O₃ for photocatalytic water splitting by reduction treatment at moderate temperature. International Journal of Hydrogen Energy, 2010, 35(11): 5270–5275

[21] Zhang H, Li X, Su H, . Sol-gel synthesis of upconversion perovskite/attapulgite heterostructures for photocatalytic fixation of nitrogen. Journal of Sol-Gel Science and Technology, 2019, 92(1): 154–162

[22] Zuo S, Liu Z, Liu W, . TiO₂ nanorod arrays on the conductive mica combine photoelectrochemical cathodic protection with barrier properties. Journal of Alloys and Compounds, 2019, 776: 529–535

[23] Dhoble S J, Deshpande S P, Pode R B, . Radiation-induced defects in Pr³⁺-activated Liyf4 laser host. Radiation Effects and Defects in Solids, 2004, 159(11‒12): 667–679

[24] Li X, Yan X, Lu X, . Photo-assisted selective catalytic reduction of NO by Z-scheme natural clay based photocatalyst: Insight into the effect of graphene coupling. Journal of Catalysis, 2018, 357: 59–68

[25] Ye L, Han C, Ma Z, . Ni₂P loading on Cd_0.5Zn_0.5S solid solution for exceptional photocatalytic nitrogen fixation under visible light. Chemical Engineering Journal, 2017, 307: 311–318

[26] Piland G B, Huang Z, Tang M L, . Dynamics of energy transfer from CdSe nanocrystals to triplet states of anthracene ligand molecules. The Journal of Physical Chemistry C, 2016, 120(11): 5883–5889

[27] Cates E L, Cho M, Kim J H. Converting visible light into UVC: microbial inactivation by Pr³⁺-activated upconversion materials. Environmental Science & Technology, 2011, 45(8): 3680–3686

[28] Li S, Guo Y, Zhang L, . Visible-light photocatalytic activity of Pt supported TiO₂ combined with up-conversion luminescence agent (Er³⁺:Y₃Al₅O₁₂) for hydrogen production from aqueous methanol solution. Journal of Power Sources, 2014, 252: 21–27

[29] Cates E L, Wilkinson A P, Kim J H. Visible-to-UVC upconversion efficiency and mechanisms of Lu₇O₆F₉:Pr³⁺ and Y₂SiO₅:Pr³⁺ ceramics. Journal of Luminescence, 2015, 160: 202–209

[30] Gao W, Zhang W, Lu G. A two-pronged strategy to enhance visible-light-driven overall watersplitting via visible-to-ultraviolet upconversion coupling with hydrogen-oxygen recombination inhibition. Applied Catalysis B: Environmental, 2017, 212: 23–31

Disclosure of potential conflicts of interests

The author(s) declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.

Acknowledgements

This work was supported by the National Natural Science Foundation of China (Grant Nos. 51674043 and 51702026) and the Postgraduate Research & Practice Innovation Program of Jiangsu Province (SJCX18_0951).

RIGHTS & PERMISSIONS

2020 Higher Education Press and Springer-Verlag GmbH Germany, part of Springer Nature