Encapsulation of Co single sites in covalent triazine frameworks for photocatalytic production of syngas

doi:10.1016/S1872-2067(20)63603-8

Abstract

Abstract:

The photocatalytic production of syngas using a noble-metal-free catalytic system is a promising approach for renewable energy and environmental sustainability. In this study, we demonstrate an efficient catalytic system formed by integrating Co single sites, which act as the active sites, in covalent triazine frameworks (CTFs), which act as the photoabsorber, for the photocatalytic production of syngas from CO₂ in aqueous solution. The enhanced light absorption of the CTFs, which contain intramolecular heterojunctions, in conjunction with 0.8 mmol L^-1 of the Co complex enables excellent syngas production with a yield of 3303 μmol g ^-1 (CO:H₂= 1.4:1) in 10 h, which is about three times greater than that achieved using CTF without a heterojunction. In the photocatalytic reaction, the coordinated single Co centers accept the photogenerated electrons from the CTF, and serve as active sites for CO₂ conversion through an adsorption-activation-reaction mechanism. Theoretical calculations further reveal that the intramolecular heterojunctions highly promote photogenerated charge separation, thus boosting photocatalytic syngas production. This work reveals the promising potential of CTFs for single-metal-site-based photocatalysis.

Key words: Photocatalysis, Covalent triazine frameworks, CO₂ reduction, Single site, Syngas

Yajun He, Xin Chen, Chi Huang, Liuyi Li, Chengkai Yang, Yan Yu. Encapsulation of Co single sites in covalent triazine frameworks for photocatalytic production of syngas[J]. Chinese Journal of Catalysis, 2021, 42(1): 123-130.

×
share this article

Add to citation manager EndNote|Ris|BibTeX

URL: https://www.cjcatal.com/EN/10.1016/S1872-2067(20)63603-8

https://www.cjcatal.com/EN/Y2021/V42/I1/123

Figures/Tables 7

Fig. 1. Schematic of the synthesis of CTF-TPN and CTF-TDPN and their application in the photocatalytic reduction of CO2 under visible light.

Fig. 2. (a) FTIR spectra of the monomers and CTFs; (b) Solid state 13C NMR spectra, (c) N 1s XPS profiles, and (d) XRD patterns of CTF-TPN and CTF-TDPN.

Fig. 3. (a) N2 adsorption-desorption isotherms at 77 K (inset: pore size distribution); (b) CO2 adsorption-desorption isotherms at 273 K (inset: isotherms of the heat of adsorption for CO2) of CTF-TPN and CTF-TDPN; (c) TEM image of CTF-TDPN; (d) UV-vis DRS spectra; (e) band gaps of the CTFs; (f) band structures of the CTFs.

Fig. 4. Photocatalytic evolution of CO and H2 by (a) CTF-TPN and (b) CTF-TDPN; (c) comparison of the average CO and H2 evolution efficiencies of the CTFs; (d) control experiments using CTF-TDPN; (e) experiments using different solvents; (f) experiments with different H2O contents in the reaction. MeCN, DMF, DMC, and Diox are acetonitrile, N,N-dimethylformamide, N,N-dimethylacetamide, and 1,4-dioxane, respectively.

Fig. 5. (a) TEM image and (b) EDX mapping of the recovered CTF-TDPN.

Fig. 6. (a) PL spectra under 365 nm excitation at room temperature (Inset: CTFs under 365 nm UV-light); (b) time-resolved fluorescence emission decay spectra; (c) transient photocurrents under visible light (≥ 420 nm) irradiation of CTF-TPN, CTF-TDPN, and CTF-HUST-1; (d) UV-vis absorption spectra of [Co(bpy)3]2+ formed in situ by the consecutive addition of bpy to Co(OAc)2?4H2O in MeCN/H2O (ν/ν = 3:1); (e) CV curves of the self-assembled [Co(bpy)3]2+ under Ar and CO2 atmospheres; (f) PL spectra of CTF-TDPN with [Co(bpy)3]2+ in MeCN/H2O upon irradiation at 365 nm.

Fig. 7. HOMOs and LUMOs of (a) CTF-TPN and (b) CTF-HUST-1; ESP maps of (c) CTF-TPN and (d) CTF-HUST-1; (e) proposed mechanism for the photocatalytic syngas production with [Co(bpy)3]2+ as a catalyst under visible light irradiation.

References

[1]	Y. F. Zhao, G. I. N. Waterhouse, G. B. Chen, X. Y. Xiong, L. Z. Wu, C. H. Tung, T. R. Zhang, Chem. Soc. Rev., 2019, 48, 1972-2010.
[2]	X. Li, J. Yu, M. Jaroniec, X. Chen, Chem. Rev., 2019, 119, 3962-4179.
[3]	J. M. Spurgeon, B. Kumar, Energy Environ. Sci., 2018, 11, 1536-1551.
[4]	M. D. Porosoff, B. H. Yan, J. G. Chen, Energy Environ. Sci., 2016, 9, 62-73.
[5]	H. Wang, Y. Wang, L. Guo, X. Zhang, C. Ribeiro, T. He, Chin. J. Catal., 2020, 41, 131-139.
[6]	M. Liu, Y. F. Mu, S. Yao, S. Guo, X. W. Guo, Z. M. Zhang, T. B. Lu, Appl. Catal. B, 2019, 245, 496-501.
[7]	J. C. Hu, M. X. Gui, W. Xia, J. Wu, Y. N. Zhou, N. D. Feng, J. W. Xiao, H. F. Liu, C. H. Tung, L. Z. Wu, F. Wang, J. Mater. Chem. A, 2019, 7, 10475-10482.
[8]	J. S. Lee, D. I. Won, W. J. Jung, H. J. Son, C. Pac, S. O. Kang, Angew. Chem. Int. Ed., 2017, 56, 976-980.
[9]	A. Li, T. Wang, X. Chang, Z. J. Zhao, C. Li, Z. Huang, P. Yang, G. Zhou, J. Gong, Chem. Sci., 2018, 9, 5334-5340.
[10]	M. Liu, S. Wageh, A. A. Al-Ghamdi, P. Xia, B. Cheng, L. Zhang, J. Yu, Chem. Commun., 2019, 55, 14023-14026.
[11]	X. Li, C. Liu, D. Wu, J. Li, P. Huo, H. Wang, Chin. J. Catal., 2019, 40, 928-939.
[12]	J. Low, B. Dai, T. Tong, C. Jiang, J. Yu, Adv. Mater., 2019, 31, 1802981.
[13]	J. Jiang, S. Cao, C. Hu, C. Chen, Chin. J. Catal., 2017, 38, 1981-1989.
[14]	B. P. Biswal, H. A. Vignolo-González, T. Banerjee, L. Grunenberg, G. Savasci, K. Gottschling, J. Nuss, C. Ochsenfeld, B. V. Lotsch, J. Am. Chem. Soc., 2019, 141, 11082-11092.
[15]	W. Zhong, R. Sa, L. Li, Y. He, L. Li, J. Bi, Z. Zhuang, Y. Yu, Z. Zou, J. Am. Chem. Soc., 2019, 141, 7615-7621.
[16]	W. T. Eckenhoff, Coord. Chem. Rev. , 2018, 373, 295-316.
[17]	J. W. Wang, W. J. Liu, D. C. Zhong, T. B. Lu, Coord. Chem. Rev., 2019, 378, 237-261.
[18]	J. Xiao, W. Yang, S. Gao, C. Sun, Q. Li, J. Mater. Sci. Technol., 2018, 34, 2331-2336.
[19]	C. Bie, B. Zhu, F. Xu, L. Zhang, J. Yu, Adv. Mater., 2019, 31, e1902868.
[20]	D. T. Genna, A. G. Wong-Foy, A. J. Matzger, M. S. Sanford, J. Am. Chem. Soc., 2013, 135, 10586-10589.
[21]	Q. Xie, W. He, S. Liu, C. Li, J. Zhang, P. K. Wong, Chin. J. Catal., 2020, 41, 140-153.
[22]	W. Yu, D. Xu, T. Peng, J. Mater. Chem. A, 2015, 3, 19936-19947.
[23]	D. Li, Y. Huang, S. Li, C. Wang, Y. Li, X. Zhang, Y. Liu, Chin. J. Catal., 2020, 41, 154-160.
[24]	X. Liu, M. Ye, S. Zhang, G. Huang, C. Li, J. Yu, P. K. Wong, S. Liu, J. Mater. Chem. A, 2018, 6, 24245-24255.
[25]	J. Bi, W. Fang, L. Li, J. Wang, S. Liang, Y. He, M. Liu, L. Wu, Macromol. Rapid Commun., 2015, 36, 1799-1805.
[26]	M. Liu, Q. Huang, S. Wang, Z. Li, B. Li, S. Jin, B. Tan, Angew. Chem. Int. Ed., 2018, 57, 11968-11972.
[27]	S. Kuecken, A. Acharjya, L. Zhi, M. Schwarze, R. Schomacker, A. Thomas, Chem. Commun., 2017, 53, 5854-5857.
[28]	Z. A. Lan, Y. Fang, Y. Zhang, X. Wang, Angew. Chem., Int. Ed., 2018, 57, 470-474.
[29]	K. Cui, W. Zhong, L. Li, Z. Zhuang, L. Li, J. Bi, Y. Yu, Small, 2019, 15, 1804419.
[30]	W. Huang, B. C. Ma, H. Lu, R. Li, L. Wang, K. Landfester, K. A. I. Zhang, ACS Catal., 2017, 7, 5438-5442.
[31]	H. S. Jena, C. Krishnaraj, G. Wang, K. Leus, J. Schmidt, N. Chaoui, P. Van Der Voort, Chem. Mater., 2018, 30, 4102-4111.
[32]	S. Padmanaban, G. H. Gunasekar, M. Lee, S. Yoon, ACS Sustain. Chem. Eng., 2019, 7, 8893-8899.
[33]	Y. Ren, D. Zeng, W. J. Ong, Chin. J. Catal., 2019, 40, 289-319.
[34]	H. Zhong, Z. Hong, C. Yang, L. Li, Y. Xu, X. Wang, R. Wang, ChemSusChem, 2019, 12, 4493-4499.
[35]	S. Hug, M. E. Tauchert, S. Li, U. E. Pachmayr, B. V. Lotsch, J. Mater. Chem., 2012, 22, 13956-13964.
[36]	H. Zhong, C. Yang, L. Li, Y. Xu, X. Wang, R. Wang, ChemSusChem, 2019, 12, 4493-4499.
[37]	Q. Wang, W. Wang, L. Zhang, Y. Su, K. Wang, H. Wu, J. Mater. Sci. Technol., 2018, 34, 2337-2341.
[38]	M. Liu, Q. Huang, S. Wang, Z. Li, B. Li, S. Jin, B. Tan, Angew. Chem. Int. Ed., 2018, 57, 11968-11972.
[39]	Z. Zhou, W. Zhong, K. Cui, Z. Zhuang, L. Li, L. Li, J. Bi, Y. Yu, Chem. Commun., 2018, 54, 9977-9980.
[40]	K. Wang, L. Yang, X. Wang, L. Guo, G. Cheng, C. Zhang, S. Jin, B. Tan, A. Cooper, Angew. Chem. Int. Ed., 2017, 56, 14149-14153.
[41]	J. Low, B. Cheng, J. Yu, Appl. Surf. Sci., 2017, 392, 658-686.
[42]	Y. Xia, Z. Tian, T. Heil, A. Meng, B. Cheng, S. Cao, J. Yu, M. Antonietti, Joule, 2019, 3, 2792-2805.
[43]	E. X. Han, Y. Y. Li, Q. H. Wang, W. Q. Huang, L. Luo, W. Hu, G. F. Huang, J. Mater. Sci. Technol., 2019, 35, 2288-2296.
[44]	J. Low, J. Yu, M. Jaroniec, S. Wageh, A. A. Al-Ghamdi, Adv. Mater., 2017, 29, 1601694.
[45]	Y. Xu, Y. Ye, T. Liu, X. Wang, B. Zhang, M. Wang, H. Han, C. Li, J. Am. Chem. Soc, 2016, 138, 10726-10729.