Modulating the Selectivity of Photocatalytic CO₂ Reduction in Barium Titanate by Introducing Oxygen Vacancies

Abstract

Artificial photosynthetic reduction of CO₂ into valuable chemicals is one of the most promising approaches to solve the energy crisis and decreasing atmospheric CO₂ emissions. However, the poor selectivity accompanied by the low activity of photocatalysts limits the development of photocatalytic CO₂ reduction. Herein, inspired by the use of oxygen vacancy engineering to promote the adsorption and activation of CO₂ molecules, we introduced oxygen vacancies in the representative barium titanate (BaTiO₃) photocatalyst for photocatalytic CO₂ reduction. We found that oxygen vacancies brought significant differences in the CO₂ photoreduction activity and selectivity of BaTiO₃. The intrinsic BaTiO₃ showed a low photocatalytic activity with the dominant product of CO, whereas BaTiO₃ with oxygen vacancies exhibited a tenfold improvement in photocatalytic activity, with a high selectivity of ~ 90% to CH₄. We propose that the presence of oxygen vacancies promotes CO₂ and H₂O adsorption onto the BaTiO₃ surface and also improves the separation and transfer of photogenerated carriers, thereby boosting the photocatalytic CO₂ reduction to CH₄. This work highlights the essential role of oxygen vacancies in tuning the selectivity of photocatalytic reduction of CO₂ into valuable chemicals.

Keywords

Photocatalytic CO₂ reduction / Oxygen vacancy / Selectivity modulation / Barium titanate

References

[1] Navarro-Jaén S, Virginie M, Bonin J, et al. Highlights and challenges in the selective reduction of carbon dioxide to methanol. Nat Rev Chem, 2021, 5(8): 564-579.

[2] Fu JW, Jiang KX, Qiu XQ, et al. Product selectivity of photocatalytic CO₂ reduction reactions. Mater Today, 2020, 32: 222-243.

[3] Nahar S, Zain MFM, Kadhum AAH, et al. Advances in photocatalytic CO₂ reduction with water: a review. Materials, 2017, 10(6): 629.

[4] Zhang GG, Li GS, Heil T, et al. Tailoring the grain boundary chemistry of polymeric carbon nitride for enhanced solar hydrogen production and CO₂ reduction. Angew Chem Int Ed Engl, 2019, 58(11): 3433-3437.

[5] Ran J, Jaroniec M, Qiao SZ Cocatalysts in semiconductor-based photocatalytic CO₂ reduction: achievements, challenges, and opportunities. Adv Mater, 2018, 30(7): 1704649.

[6] Chang XX, Wang T, Gong JL CO₂ photo-reduction: insights into CO₂ activation and reaction on surfaces of photocatalysts. Energy Environ Sci, 2016, 9(7): 2177-2196.

[7] Wagner A, Sahm CD, Reisner E Towards molecular understanding of local chemical environment effects in electro- and photocatalytic CO₂ reduction. Nat Catal, 2020, 3(10): 775-786.

[8] Halmann M Photoelectrochemical reduction of aqueous carbon dioxide on p-type gallium phosphide in liquid junction solar cells. Nature, 1978, 275(5676): 115-116.

[9] Chen XB, Liu L, Yu PY, et al. Increasing solar absorption for photocatalysis with black hydrogenated titanium dioxide nanocrystals. Science, 2011, 331(6018): 746-750.

[10] Chen F, Ma TY, Zhang TR, et al. Atomic-level charge separation strategies in semiconductor-based photocatalysts. Adv Mater, 2021, 33(10): 2005256.

[11] Dong CC, Ji JH, Yang Z, et al. Research progress of photocatalysis based on highly dispersed titanium in mesoporous SiO₂. Chin Chem Lett, 2019, 30(4): 853-862.

[12] Huo HL, Liu D, Feng H, et al. Double-shelled Cu₂O/MnO _x mesoporous hollow structure for CO₂ photoreduction with enhanced stability and activity. Nanoscale, 2020, 12(26): 13912-13917.

[13] Qiu CH, Bai S, Cao WJ, et al. Tunable syngas synthesis from photocatalytic CO₂ reduction under visible-light irradiation by interfacial engineering. Trans Tianjin Univ, 2020, 26(5): 352-361.

[14] Zhao ZJ, Liu ZL, Zhu ZX, et al. Ultrathin zinc selenide nanosheet-based intercalation hybrid coupled with CdSe quantum dots showing enhanced photocatalytic CO₂ reduction. Chin Chem Lett, 2021, 32(8): 2474-2478.

[15] Yoshino S, Takayama T, Yamaguchi Y, et al. CO₂ reduction using water as an electron donor over heterogeneous photocatalysts aiming at artificial photosynthesis. Acc Chem Res, 2022, 55(7): 966-977.

[16] Collado L, Reñones P, Fermoso J, et al. The role of the surface acidic/basic centers and redox sites on TiO₂ in the photocatalytic CO₂ reduction. Appl Catal B Environ, 2022, 303: 120931.

[17] Lan ZA, Wang XC ChemInform abstract: merging surface organometallic chemistry with graphitic carbon nitride photocatalysis for CO₂ photofixation. ChemCatChem, 2015, 7(9): 1422-1423.

[18] Ye LQ, Wu D, Chu KH, et al. Phosphorylation of g-C₃N₄ for enhanced photocatalytic CO₂ reduction. Chem Eng J, 2016, 304: 376-383.

[19] Liu Q, Cheng H, Chen TX, et al. Regulating the *OCCHO intermediate pathway towards highly selective photocatalytic CO₂ reduction to CH₃CHO over locally crystallized carbon nitride. Energy Environ Sci, 2022, 15(1): 225-233.

[20] Xi GC, Ouyang SX, Li P, et al. Ultrathin W18O49 nanowires with diameters below 1 nm: synthesis, near-infrared absorption, photoluminescence, and photochemical reduction of carbon dioxide. Angew Chem Int Ed Engl, 2012, 51(10): 2395-2399.

[21] Tahir M, Amin NS Indium-doped TiO₂ nanoparticles for photocatalytic CO₂ reduction with H₂O vapors to CH₄. Appl Catal B Environ, 2015, 162: 98-109.

[22] Dimitrijevic NM, Vijayan BK, Poluektov OG, et al. Role of water and carbonates in photocatalytic transformation of CO₂ to CH₄ on titania. J Am Chem Soc, 2011, 133(11): 3964-3971.

[23] Wang Y, Zhang ZZ, Zhang LN, et al. Visible-light driven overall conversion of CO₂ and H₂O to CH₄ and O₂ on 3D-SiC@2D-MoS₂ heterostructure. J Am Chem Soc, 2018, 140(44): 14595-14598.

[24] Li XD, Sun YF, Xu JQ, et al. Selective visible-light-driven photocatalytic CO₂ reduction to CH₄ mediated by atomically thin CuIn₅S₈ layers. Nat Energy, 2019, 4(8): 690-699.

[25] Zeng GT, Qiu J, Li Z, et al. CO₂ reduction to methanol on TiO₂-passivated GaP photocatalysts. ACS Catal, 2014, 4(10): 3512-3516.

[26] Dai WL, Xu H, Yu JJ, et al. Photocatalytic reduction of CO₂ into methanol and ethanol over conducting polymers modified Bi₂WO₆ microspheres under visible light. Appl Surf Sci, 2015, 356: 173-180.

[27] Liu YY, Huang BB, Dai Y, et al. Selective ethanol formation from photocatalytic reduction of carbon dioxide in water with BiVO₄ photocatalyst. Catal Commun, 2009, 11(3): 210-213.

[28] Sun SM, Watanabe M, Wu J, et al. Ultrathin WO₃·0.33H₂O nanotubes for CO₂ photoreduction to acetate with high selectivity. J Am Chem Soc, 2018, 140(20): 6474-6482.

[29] Li H, Li J, Ai ZH, et al. Oxygen vacancy-mediated photocatalysis of BiOCl: reactivity, selectivity, and perspectives. Angew Chem Int Ed Engl, 2018, 57(1): 122-138.

[30] Wang JL, Kang SH, Zhu XG, et al. Highly ordered Nb₂O₅ nanochannel film with rich oxygen vacancies for electrocatalytic N₂ reduction: inactivation and regeneration of electrode. Chin Chem Lett, 2021, 32(9): 2833-2836.

[31] Yang S, Halliburton LE, Manivannan A, et al. Photoinduced electron paramagnetic resonance study of electron traps in TiO₂ crystals: oxygen vacancies and Ti³⁺ ions. Appl Phys Lett, 2009, 94(16): 162114.

[32] Lei FC, Sun YF, Liu KT, et al. Oxygen vacancies confined in ultrathin indium oxide porous sheets for promoted visible-light water splitting. J Am Chem Soc, 2014, 136(19): 6826-6829.

[33] Liao JZ, Li KL, Ma H, et al. Oxygen vacancies on the BiOCl surface promoted photocatalytic complete NO oxidation via superoxide radicals. Chin Chem Lett, 2020, 31(10): 2737-2741.

[34] Ma ZY, Li PH, Ye LQ, et al. Oxygen vacancies induced exciton dissociation of flexible BiOCl nanosheets for effective photocatalytic CO₂ conversion. J Mater Chem A, 2017, 5(47): 24995-25004.

[35] Wu SQ, Wang JB, Li QC, et al. Bi/BiOCl nanosheets enriched with oxygen vacancies to enhance photocatalytic CO₂ reduction. Trans Tianjin Univ, 2021, 27(2): 155-164.

[36] Li Q, Liu YN, Wan Z, et al. Microwave-assisted synthesis of oxygen vacancy associated TiO₂ for efficient photocatalytic nitrate reduction. Chin Chem Lett, 2022, 33(8): 3835-3841.

[37] Jiang LS, Li Y, Wu XY, et al. Rich oxygen vacancies mediated bismuth oxysulfide crystals towards photocatalytic CO₂-to-CH₄ conversion. Sci China Mater, 2021, 64(9): 2230-2241.

[38] Ji YF, Luo Y New mechanism for photocatalytic reduction of CO₂ on the anatase TiO₂ (101) surface: the essential role of oxygen vacancy. J Am Chem Soc, 2016, 138(49): 15896-15902.

[39] Ye LQ, Deng Y, Wang L, et al. Bismuth-based photocatalysts for solar photocatalytic carbon dioxide conversion. Chemsuschem, 2019, 12(16): 3671-3701.

[40] Wang Y, Liu RZ, Shi M, et al. Photo-induced carbon dioxide reduction on hexagonal tungsten oxide via an oxygen vacancies-involved process. Chin Chem Lett, 2022

[41] Yu HJ, Chen F, Li XW, et al. Synergy of ferroelectric polarization and oxygen vacancy to promote CO₂ photoreduction. Nat Commun, 2021, 12(1): 1-10.

[42] Zhao Z, Wang DD, Gao R, et al. Magnetic-field-stimulated efficient photocatalytic N₂ fixation over defective BaTiO3 perovskites. Angew Chem Int Ed Engl, 2021, 60(21): 11910-11918.

[43] Zhao ZY, Li GR, Wang Z, et al. Black BaTiO₃ as multifunctional sulfur immobilizer for superior lithium sulfur batteries. J Power Sources, 2019, 434: 226729.

[44] Hayashi H, Nakamura T, Ebina T In-situ Raman spectroscopy of BaTiO₃ particles for tetragonal-cubic transformation. J Phys Chem Solids, 2013, 74(7): 957-962.

[45] Guo M, Lu JQ, Wu YN, et al. UV and visible Raman studies of oxygen vacancies in rare-earth-doped ceria. Langmuir, 2011, 27(7): 3872-3877.

[46] Wang YT, Cai JM, Wu MQ, et al. Rational construction of oxygen vacancies onto tungsten trioxide to improve visible light photocatalytic water oxidation reaction. Appl Catal B Environ, 2018, 239: 398-407.

[47] Kovacic Z, Likozar B, Hus M Photocatalytic CO₂ reduction: a review of ab initio mechanism, kinetics, and multiscale modeling simulations. ACS Catal, 2020, 10(24): 14984-15007.

[48] Tan SS, Zou LD, Hu E Kinetic modelling for photosynthesis of hydrogen and methane through catalytic reduction of carbon dioxide with water vapour. Catal Today, 2008, 131(1–4): 125-129.