Strategies to engineer metal-organic frameworks for efficient photocatalysis

doi:10.1016/S1872-2067(23)64556-5

Chinese Journal of Catalysis ›› 2023, Vol. 55: 1-19.DOI: 10.1016/S1872-2067(23)64556-5

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Strategies to engineer metal-organic frameworks for efficient photocatalysis

Cheng Liu^a, Hurunqing Liu^a, Jimmy C. Yu^a^,^b, Ling Wu^a^,^*(), Zhaohui Li^a^,^*()

^aResearch Institute of Photocatalysis, State Key Laboratory of Photocatalysis on Energy and Environment, College of Chemistry, Fuzhou University, Fuzhou 350116, Fujian, China
^bDepartment of Chemistry, The Chinese University of Hong Kong, Shatin, New Territories, Hong Kong, China

Received:2023-09-12 Accepted:2023-10-31 Online:2023-12-18 Published:2023-12-07
Contact: *E-mail: zhaohuili@fzu.edu.cn (Z. Li), wuling@fzu.edu.cn (L. Wu).
About author:Ling Wu (State Key Laboratory of Photocatalysis on Energy and Environment, Fuzhou University) received his Ph.D degree in 2004 from The Chinese University of Hong Kong. His research interests currently focus on photocatalysis and new materials based on MOFs and ultrathin inorganic metal oxide nanosheets, especially revealing the relationship of the surface structure and performances at molecular level. He has coauthored more than 260 peer-reviewed papers.
Zhaohui Li (State Key Laboratory of Photocatalysis on Energy and Environment, Fuzhou University) received her Bachelor degree from Fudan University in 1990, Master degree from Fujian Institute of Research on Structure of Matter, Chinese Academy of Science in 1996, and PhD degree from National University of Singapore in 2000. She carried out postdoctoral research at University of Notre Dame (USA) from 2000 to 2002. She joined the faculty of Fuzhou University in 2003 and is currently a full professor of State Key Laboratory of Photocatalysis on Energy and Environment, Fuzhou University. Her current research interest centers on the development of porous/nanostructured materials, in particular the MOFs materials, for photocatalytic applications, especially in photocatalytic organics transformations.
Supported by:
National Natural Science Foundation of China(22372038);National Natural Science Foundation of China(22272026);111 Project(D16008)

Abstract

Abstract:

Photocatalysis, a promising technology to convert solar energy to chemical energy, is expected to relieve the global energy shortage and environmental pollution and therefore has attracted widespread recent research attention. Metal-organic frameworks (MOFs), a class of micro-mesoporous hybrid material constructed from metal or metal nodes interconnected with multi-dentated organic linkers, have recently been demonstrated to be promising photocatalysts for a variety of reactions relevant to environmental and energy concerns due to their unique structure and characteristics. Considering that MOF-based photocatalysis burgeoned rapidly during the past several years, and with an aim to develop more efficient MOF-based photocatalytic materials, it is still necessary to summarize the strategies already reported to improve the performance of MOF-based photocatalytic materials, even though several excellent reviews on MOF-based photocatalysis have already been published. In this review, four structural engineering strategies to improve the efficiency of MOF-based photocatalysis have been summarized. These strategies include metal doping, ligand functionalization, the fabrication of ultrathin 2D MOFs, and defect engineering. These methods aim to enhance light absorption, improve charge separation and transportation, and create more catalytic active sites. Personal opinions on the opportunities, challenges, and developing trends of MOF-based photocatalysis were addressed. This review aims to provide guidance for the rational development of advanced MOF-based photocatalysts by elucidating the inherent relationship between their structural properties and catalytic activity.

Key words: Metal-organic framework, Photocatalysis, Metal doping, Ligand functionalization, Ultrathin 2D MOFs, Defect engineering

Cheng Liu, Hurunqing Liu, Jimmy C. Yu, Ling Wu, Zhaohui Li. Strategies to engineer metal-organic frameworks for efficient photocatalysis[J]. Chinese Journal of Catalysis, 2023, 55: 1-19.

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Figures/Tables 18

Fig. 1. Concept of MOFs by interconnecting metal ions/clusters with multi-dentated organic ligands to form a crystalline network via the coordination bonds.

Fig. 5. (a) TEM image and corresponding EDS elemental mapping images of MIL-100(Fe0.63Al0.37). Reprinted with permission from Ref. [61]. Copyright 2022, Elsevier. (b) The mechanism of NNU-31-M CO2RR with H2O oxidation. The free-energy profile for the CO2RR pathway (c) and OER pathway (d). Reprinted with permission from Ref. [62]. Copyright 2019, Wiley-VCH. (e) Schematic illustration of synthetic of the PCN-250-Fe3 and PCN-250-Fe2M (Mn, Zn, Ni, Co) by Fe3 or Fe2M and H4abtc. (f) Comparison of photocatalytic activity of PCN-250-Fe3 and PCN-250-Fe2M for CO evolution. Reprinted with permission from Ref. [69]. Copyright 2020, Elsevier.

Table 1 Summary of metal doped MOF-based photocatalytic systems.

No.	MOFs	Method	Application	Ref.
1	Cu-doped NH₂-MIL-125(Ti)	Cu(NO₃)₂ + Ti(OC₄H₉)₄ + NH₂-BDC, 150 °C, 24 h	pollutant degradation	[57]
2	Fe-doped NH₂-MIL-68(In)	In(NO₃)₃ + Fe(NO₃)₃ + NH₂-BDC, 125 °C, 5 h	pollutant degradation	[65]
3	V-doped NH₂-MIL-125(Ti)	VCl₃ + Ti(OCH(CH₃)₂)₄ + NH₂-BDC, 120 °C, 72 h	none	[56]
4	Nb-doped NH₂-UiO-66(Zr)	NbCl₅ + ZrCl₄ + NH₂-BDC, 120 °C, 48 h	none	[56]
5	Ti-doped NH₂-UiO-66(Zr)	NH₂-UiO-66(Zr) + TiCl₄(THF)₂, 100 °C for 4 d	CO₂ reduction, H₂ evolution	[58,59]
6	Hf-doped-SH-UiO-66(Zr)	ZrCl₄ + HfCl₄ + 2SH-BDC, 120 °C, 48 h	N₂ fixation	[66]
7	Ce/Ti-doped UiO-66(Zr)	UiO-66(Zr/Ce) + TiCl₄(THF)₂, 120 °C, 4 d	H₂ evolution, O₂ evolution	[67]
8	Ni-doepd NH₂-MIL-125(Ti)	Ni(NO₃)₂ + Ti(OC₄H₉)₄ + NH₂-BDC, 150 °C, 20 h	CO₂ reduction	[68]
9	Al-doped MIL-100(Fe)	AlCl₃ + FeCl₃ + 1,3,5-benzene tricarboxylate, 150 °C, 36 h	organic syntheses	[61]
10	Co, Ni, Zn-doped NNU-31-M	Fe₂M(Co, Ni, Zn) cluster + TCA, 150 °C, 32 h	CO₂ reduction coupled with H₂O oxidation	[62]
11	Mn, Zn, Ni, Co-doped PCN-250-Fe₃	Fe₂M (Mn, Zn, Ni, Co) + H₄abtc, 140 °C, 2 h	CO₂ reduction	[69]
12	Co-doped Cu-MOF	Cu(NO₃)₂ + Co(NO₃)₂+ TCPP, 80 °C, 24 h	N₂ fixation	[70]

Fig. 6. (a) UV-vis spectra of MIL-125(Ti) (a) and NH2-MIL-125(Ti) (b). (b) Proposed mechanism for the photocatalytic CO2 reduction over NH2-MIL-125(Ti) under visible light irradiation. Reprinted with permission from Ref. [75]. Copyright 2012, Wiley-VCH. Frontier electron density of unsubstituted MIL-125: (c) the valence band is composed of the bdc C 2p orbitals, making these favorable for linker-based band gap modifications; (d) the conduction band is composed of O 2p orbitals and Ti 3d orbitals, suggesting that modifications of the aromatic bdc units are unlikely to affect the CB. Reprinted with permission from Ref. [73]. Copyright 2013, American Chemical Society.

Table 2 Absorption energies (Eabs, in eV) and ligand-to-metal charge-transfer energies (ELMCT, in eV) of UiO-66(Ce)-X. Reprinted with permission from Ref. [84]. Copyright 2018, American Chemical Society.

Energy	H	NH₂	NO₂	F	Cl	Br	I	OH	SH	COOH	CH₃	CF₃
E_abs	4.09	2.74	3.77	3.83	3.57	3.42	2.97	3.02	2.54	3.43	3.83	4.03
E_LMCT	-1.43	-1.57	-1.33	-1.38	-1.39	-1.42	-1.44	-1.61	-1.59	-1.65	-1.47	-1.35

Fig. 7. (a) Illustration showing the dark photocatalysis over MIL-125 and MIL-125 with different functional groups, MIL-125-X (X = NH2, NO2, Br). (b) Overlapping percentage and distance between electrons and holes in MIL-125 and MIL-125-X (X = NH2, NO2). Reprinted with permission from Ref. [87]. Copyright 2022, Royal Society of Chemistry. (c) Photocatalytic reduction of aqueous Cr(VI) over UiO-66-X (X = H, NH2, NO2 and Br) under simulated sunlight (320-780 nm). Reprinted with permission from Ref. [88]. Copyright 2015, Royal Society of Chemistry. Transient photocurrent response (d) and EIS Nyquist plots (e) of MIL-68(In)-X (X = H, NH2, NO2, Br). Reprinted with permission from Ref. [89]. Copyright 2018, Elsevier.

Fig. 8. (a) TEM image (scale bar: 500 nm). (b) AFM image and corresponding height profile. Reprinted with permission from Ref. [97]. Copyright 2018, Wiley-VCH. (c) Illustration for the synthesis of 2D Ln-TCPP nanosheets and the thickness- and metal-node-dependent photocatalytic activity. Reprinted with permission from Ref. [98]. Copyright 2020, Wiley-VCH. (d) Schematic of the synthesis process of Mn-TBAPy-BK (bulk) and Mn-TBAPy-NS (nanosheets) MOFs. (e) Photocatalytic H2 evolution activities of Mn-TBAPy-BK and Mn-TBAPy-NS before (left) and after (right) normalized to Pt content. Reprinted with permission from Ref. [104]. Copyright 2022, American Chemical Society.

Table 3 Summary of MOF-based photocatalytic systems obtained via ligand functionalization.

No.	MOFs	Method	Application	Ref.
1	NH₂-MIL-125(Ti)	Ti(OC₄H₉)₄+ NH₂-BDC, 150 °C, 72 h	CO₂ reduction	[75]
2	NH₂-MIL-125(Ti)	Ti(OC₃H₇)₄) + NH₂-BDC, 150 °C, 48 h	H₂ production	[76]
3	NH₂-MIL-125(Ti)	Ti(OC₄H₉)₄ + NH₂-BDC, 150 °C, 72 h	organic syntheses	[77]
4	NH₂-MIL-125(Ti)	Ti(OC₄H₉)₄ + NH₂-BDC, 150 °C, 72 h	N₂ fixation	[78]
5	OH/CH₃-MIL-125(Ti)	MIL-125(Ti) + OH-BDC/CH₃-BDC, 150 °C, 72 h	N₂ fixation	[78]
6	NH₂-UiO-66(Zr)	ZrCl₄ + NH₂-BDC, 120 °C, 48 h	H₂ production	[79]
7	NH₂-UiO-66(Zr)	ZrCl₄ + NH₂-BDC, 120 °C, 48 h	Organic syntheses	[80]
8	NH₂-UiO-66(Zr)	ZrCl₄ + NH₂-BDC, 120 °C, 48 h	Cr(VI) reduction	[81]
9	NH₂-UiO-66(Zr)	ZrCl₄ + NH₂-BDC, 120 °C, 48 h	CO₂ reduction	[82]
10	NH₂-MIL-101(Fe)	FeCl₃+ NH₂-BDC, 110 °C, 24 h	CO₂ reduction	[23]
11	NH₂-MIL-53(Fe)	FeCl₃ + NH₂-BDC, 150 °C, 72 h	CO₂ reduction	[23]
12	NH₂-MIL-88B(Fe)	FeCl₃+ NH₂-BDC, 170 °C, 24 h	CO₂ reduction	[23]
13	NH₂-MIL-88B(Fe)	FeCl₃+ NH₂-BDC, 150 °C, 15 min	Cr(VI) reduction	[83]
14	NH₂/(NH₂)₂-MIL-125(Ti)	Ti(OC₃H₇)₄) + NH₂BDC/(NH₂)₂-BDC, 150 °C, 48 h	none	[73]
15	NH₂-MIL-125(Ti)	Ti-(OC₃H₇)₄) + NH₂-BDC, 110 °C, 72 h	none	[86]
16	NH₂-125(Ti)	Ti(OC₄H₉)₄ + NH₂-BDC, 130 °C, 15 h	H₂ production	[87]
17	NO₂/Br-MIL-125(Ti)	MIL-125(Ti) + OH-BDC/CH₃-BDC, 130 °C, 15 h	H₂ production	[87]
18	NH₂/NO₂/Br-UiO-66(Zr)	ZrCl₄ + NH₂-BDC/NO₂-BDC/Br-BDC, 120 °C, 48 h	Cr(VI) reduction	[88]
19	NH₂/NO₂/Br-MIL-68(In)	In(NO₃)₃ + NH₂-BDC/NO₂-BDC/Br-BDC, 125 °C, 5 h	Cr(VI) reduction	[89]
20	CH₃/NO₂/Br-UiO-66(Ce)	(NH₄)₂Ce(NO₃)₆ + CH₃-BDC/NO₂-BDC/Br-BDC, 100 °C, 15 min	organic syntheses	[90]

Fig. 9. (a) Illustration of the synthetic route towards Pt single-atom coordinated ultrathin MOF nanosheets (PtSA-MNSs) through a surfactant-stabilized coordination strategy for photocatalytic hydrogen production. Reprinted with permission from Ref. [105]. Copyright 2019, Wiley-VCH. (b) Schematic representation showing the one-pot synthesis of PCN-134-3D and stepwise synthesis of PCN-134-2D nanosheets with accessible catalytic sites. Reprinted with permission from Ref. [106]. Copyright 2019, Wiley-VCH. (c) TEM image of g-CNQDs/PMOF. (d) Proposed mechanism of CO2 reduction over g-CNQDs/PMOF hybrids under visible-light irradiation. Reprinted with permission from Ref. [107]. Copyright 2019, American Chemical Society.

Fig. 10. (a) The fs-TA spectra (pump at 400 nm) taken at several representative probe delays for UiO-66-NH2-0 and UiO-66-NH2-100. (b) fs-TA kinetics and the global fitting results (probing in the range 580-650 nm using 8 traces with a 10-nm interval) for UiO-66-NH2-X (X = 0, 50, 100, 150, 200). (c) Comparison of photocatalytic H2 production rates and average relaxation lifetimes. Reprinted with permission from Ref. [120]. Copyright 2019, Wiley-VCH.

Table 4 Summary of ultrathin 2D MOF-based photocatalytic systems.

No.	MOF nanosheet	Method	Application	Ref
1	Ni-BDC MOFs	Ni(NO₃)₂ + H₂BDC, 140 °C, 12 h, exfoliation	CO₂ reduction	[91]
2	ZIF-67(Co)	Co(NO₃)₂ + 2-methylimidazole, room temperature, 30 min	CO₂ reduction	[94]
3	Ni₃(HITP)₂ MOFs	NiCl₂ + HITP·HCl + NH₃·H₂O, 65 °C, 2 h, exfoliation	CO₂ reduction	[95]
4	Zr-porphyrinic (Ni-TCPP) MOF	ZrCl₄ + Ni-TCPP, 120 °C, 24 h	organic syntheses	[97]
5	Porphyrin-based Ln-MOF (Ln = Ce, Sm, Eu, Tb, Yb)	Ce(NO₃)₃/Sm(NO₃)₃/Sm(NO₃)₃/Yb(NO₃)₃+ HAc + H₂TCPP, 10 min, microwave	organic syntheses	[98]
6	Porphyrin-based Ti-MOF	Ti(OC₄H₉)₄ + H₂TCPP, 150 °C, 5 d	organic syntheses	[99]
7	NH₂-MIL-125(Ti)	Ti(OC₄H₉)₄ + NH₂-BDC, 120 °C, 12 h	CO₂ reduction	[100]
8	MOF-74(Ni)	Ni(CH₃COO)₂ + H₄DOBDC, 120 °C, 12 h	organic syntheses	[101]
9	[Co(Ni-H₇TPPP)₂]·8H₂O MOFs	Co(CH₃COO)₂ + Ni-H₈TPPP + HCl, exfoliation	CO₂ reduction	[102]
10	Co-MOF-Ru(tpyCOO)₂	Co(NO₃)₂ + [Ru^II(tpyCOOH)₂](PF₆)₂, 120 °C, 24 h, exfoliation	H₂ production	[103]
11	Mn-MOF	MnCl₂ + H₄TBAPy, 130 °C, 72 h, exfoliation	H₂production	[104]
12	Pt single atoms/porphyrin-based Cu-MOF	Cu(NO₃)₂ + PtTCPP, 80 °C, 4 h.	H₂production	[105]
13	Photosensitizers-anchored Zr-BTB MOF	Zr-BTB nanosheets + H₄TCPP, 100 °C for 12 h	organic syntheses	[106]
14	g-CNQDs//porphyrin-based Co-MOF	Co(NO₃)₂ + TCPP, 150 °C, 4 h.	CO₂ reduction	[107]

Fig. 12. (a) Illustration of the synthesis for defective NH2-MIL-125(Ti) via the thermal treatment. Reprinted with permission from Ref. [132]. Copyright 2021, Elsevier. (b) A plausible mechanism of linker elimination by the photothermal treatment in a water medium containing TEOA. Reprinted with permission from Ref. [133]. Copyright 2020, Elsevier. (c) Schematic illustration of the synthetic procedures for ZIF-67-MBI via SALE approach. Reprinted with permission from Ref. [135]. Copyright 2023, Elsevier.

Fig. 13. (a) Idealized process of generation of defects in UiO-66: missing linker defect and missing cluster defect. Reprinted with permission from Ref. [137]. Copyright 2017, Elsevier. (b) Illustration of the crystal structures of UiO-66-fresh, UiO-66-UV-vis, and UiO-66-PSE. Reprinted with permission from Ref. [138]. Copyright 2021, Royal Society of Chemistry. (c) Schematic illustration of varied defective structures. (d) Photoreduction CO2 to CO evolution rates over NH2-UiO-66(Zr) with different types of defects. Reprinted with permission from Ref. [139]. Copyright 2021, Elsevier.

Table 5 Summary of defect containing MOF-based photocatalytic systems.

No.	Defective MOFs	Method	Application	Ref.
1	NH₂-UiO-66(Zr)	modulation approach	H₂ production	[120]
2	Cu-BTC MOFs	mixed linker approach	H₂ production, O₂ production	[123]
3	ZIF-67(Co)	mixed linker approach	H₂ production	[124]
4	NH₂-MIL-125(Ti)	thermal treatment	Cr(VI) reduction	[132]
5	NH₂-MIL-125(Ti)	photo-thermal treatment	H₂ production	[133]
6	ZIF-67(Co)	SALE approach	H₂ production, O₂ production	[135]
7	UiO-66(Zr)	photo treatment, SALE approach	N₂ fixation	[128]
8	NH₂-MIL-125(Ti)	SALE approach	H₂production	[131]
9	MIL-125(Ti)	SALE approach	H₂O₂ production	[134]
10	NH₂-UiO-66(Zr)	modulation approach, thermal treatment	CO₂ reduction	[139]
11	(SH)₂-UiO-66(Zr)	thermal treatment	N₂ fixation	[116]

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Strategies to engineer metal-organic frameworks for efficient photocatalysis

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