Metallacage-Crosslinked Free-Standing Supramolecular Networks via Photo-induced Copolymerization for Photocatalytic Water Decontamination

doi:10.21203/rs.3.rs-4914112/v1

Download PDF

Article

Metallacage-Crosslinked Free-Standing Supramolecular Networks via Photo-induced Copolymerization for Photocatalytic Water Decontamination

https://doi.org/10.21203/rs.3.rs-4914112/v1

This work is licensed under a CC BY 4.0 License

Version 1

posted

You are reading this latest preprint version

The development of polymer materials for water decontamination makes a significant contribution to environmental protection and public health. Herein, we report the preparation of metallacage-crosslinked free-standing supramolecular networks by photo-induced copolymerization of acrylate metallacages and butyl methacrylate for water decontamination. The integration of metallacages into polymer networks endows the networks good capability for generating singlet oxygen via photosensitization, making them serve as a type of decontamination materials that can effectively eliminate diverse organic pollutants and bacterial contaminants. This study not only provides a mild and effective strategy for the preparation of metallacage-cored supramolecular networks via photo-induced copolymerization but also explores their applications for photocatalytic dye degradation and bacterial killing, which will promote the future development of metallacage-based supramolecular materials for photocatalytic applications.

Physical sciences/Chemistry/Polymer chemistry/Supramolecular polymers

Physical sciences/Materials science/Materials for energy and catalysis/Photocatalysis

Water pollution caused by chemicals and microorganisms has become a worldwide problem of our society. It is predicted that the water scarcity will reach 40% in 2030, while the water demand will increase by 55% in 2050.^{[1, 2]} Therefore, various strategies including physical adsorption,^[3–5] biodegradation,^[6–8] ozonation,^{[9, 10]} electrochemical oxidation,^[11–13] phytoremediation^[14–15] and photocatalysis^[16–19] have been developed for water decontamination. Among these strategies, photocatalysis has received much more attention owing to its low-cost, simple setup, fast processing time and relatively complete mineralisation of chemicals.^[20–23] Conventional photocatalytic materials such as metal nanoparticles, metal oxides and carbon-based materials exhibit good photo- and chemo-stability and reasonable photocatalytic efficiency, ^[24–30] but they often suffer from limited visible light absorption and poor processability, which greatly limit their applications in water decontamination. Instead, polymer networks with embedded organic photocatalysts can not only avoid the above-mentioned problem, but also provide a convenient method to finely tune the loading amount of photocatalysts for efficient photocatalysis.^[31–36] In this regard, supramolecular networks allow for the bottom-up assembly of different functional building blocks, which are advantageous in photocatalytic water decontamination because of their ease of preparation, good processability, stimuli-responsiveness and self-healing properties.

Metallacages represent a class of three-dimensional geometric structures formed by metal-coordination bonds.^[37–42] They have emerged as a type of promising photocatalysts not only due to their designable structures and tunable light absorption, but also because their confined cavities are beneficial for the loading of different substrates to enhance the excited energy transfer and thus increase the photocatalytic efficiency.^[43–46] However, for photocatalytic water decontamination, the processibility and stability of metallacages are needed to be further improved to offer the materials good recyclability and reusability. The copolymerization of metallacages and monomers provides a rational strategy to solve this problem, but common polymerization methods may break the weak metal-coordination bonds and destroy the structures of the metallacages during the harsh polymerization process.^[47–53] Moreover, the undesired side reactions and tedious purification should be avoided. An alternative approach is the photo-induced copolymerization of metallacages with conventional monomers, which features advantages such as rapid curing, solvent-free process, and mild conditions. By exposing metallacages and suitable organic monomers to UV light, the polymerization can proceed instantly, leading to metallacage-crosslinked supramolecular networks with predesigned structures and good photocatalytic efficiency.

In this work, we report the preparation of free-standing supramolecular networks by photo-induced copolymerization of acrylate metallacages with butyl methacrylate for photocatalytic water decontamination (Scheme 1). Owing to the good singlet oxygen (¹O₂) generation ability of the perylene diimide (PDI)-based metallacages, these supramolecular networks also show good photosensitivity upon irradiation, and their photosensitivity increases as the increase of the density of metallacages in the networks. Therefore, these networks can not only serve as a type of heterogeneous photocatalysts for the photocatalytic oxidative degradation of dyes, but also show the ability to kill the bacteria via photodynamic process. It is worthy noting that water purified by these networks could support the well growth of plants due to the effective degradation of dyes and the killing of bacteria in water, indicating the good performance of these polymer networks in water decontamination.

Preparation and Characterization of Metallacage 4. In order to prepare acrylate metallacages which could be used as polymeric crosslinkers, two methacrylamide groups were introduced into the tetracarboxylic ligand of the PDI-based metallacage (See the Supporting Information for synthetic details). Based on the multicomponent self-assembly of tetrapyridyl PDI (1), acrylate tetracarboxylic ligand (2), and cis-(PEt₃)₂Pt(OTf)₂ (3), metallacage 4 was synthesized and separated in 93% yield (Scheme 1). The structure of metallacage 4 was confirmed by ³¹P{¹H}, ¹H NMR, and electrospray ionization time-of-flight mass spectrometry (ESI-TOF-MS). Different from a single phosphorus environment in 3 (Fig. 1a), the ³¹P{¹H} NMR spectrum of 4 revealed two doublet peaks at 5.44 and − 0.31 ppm (Fig. 1b). These doublet peaks, accompanied by concurrent ¹⁹⁵Pt satellites, indicated the coordination of each platinum atom with one pyridyl nitrogen of the PDI face and one carboxylic oxygen of the tetracarboxylic pillar. In the ¹H NMR spectra (Figs. 1c and 1d), the α-pyridyl protons H_a and the β-pyridyl protons H_b of metallacage 4 split into two sets of signals with noticeable chemical shifts, corresponding to the protons inside and outside the cavity of metallacage. The coordination stoichiometry of 4 was determined by ESI-TOF-MS (Fig. 1e). Isotopically well-resolved peaks with charge states ranging from 4 + to 8 + were observed for 4 due to the loss of counterions (OTf⁻), confirming the right chemical composition. For example, peaks at m/z = 797.3888, 932.3615, 1112.6855, 1365.0142, 1743.5010 were found, corresponding to [4 − 8OTf]⁸⁺, [4 − 7OTf]⁷⁺, [4 − 6OTf]⁶⁺, [4 − 5OTf]⁵⁺, [4 − 4OTf]⁴⁺, respectively. These data were entirely consistent with their calculated values. To further unveil the coordination structures of 4, single crystals suitable for X-ray diffraction analysis were successfully obtained through the vapor diffusion of toluene into its DMF solution over one month. Metallacage 4 was formed by the connection of two tetrapyridyl PDI faces and two tetracarboxylic pillars via eight platinum (II)-based metal-coordination bonds (Fig. 1f and Table S1). The dimension of 4 was measured to be 1.65 × 1.41 × 0.98 nm³, based on the distance between platinum atoms. Different from previously reported PDI-based metallacages that the PDI faces and the tetracarboxylic pillars are nearly perpendicular with each other,^{[54, 55]} the two tetracarboxylic pillars in metallacage 4 were inclined and the dihedral angle between the two planes decreased into 41.9°, which was attributed to the introduction of two methacrylamide groups. The distance between the two PDI faces was ca. 11 Å. Consequently, it is anticipated that metallacage 4 is capable of complexing planar guest molecules.

The UV-vis absorption (Fig. 1g) and fluorescent experiments (Fig. 1h) were conducted to investigate the photophysical properties of 1 and 4. Ligand 1 exhibited three absorption bands derived from the absorption of typical PDI derivatives. Metallacage 4 also showed three absorption bands at 458, 490, and 526 nm, with molar absorption coefficients of 3.00 × 10⁴, 8.05 × 10⁴ and 1.25 × 10⁵ M^− 1, respectively. In the emission spectra, two emission bands were found for ligand 1 (λ_max = 552 and 583 nm) and metallacage 4 (λ_max = 546 and 581 nm). The fluorescence quantum yields (Φ_F) of 1 and 4 in CH₃CN were measured to be 95.21% and 11.43%, respectively (Figures S10 and S11). The decrease in quantum yields from 1 to 4 indicated that the metal-coordination bonds would promote the intersystem crossing from singlet state to triplet state in metallacage 4, which may increase the generation of ¹O₂ via triplet energy transfer upon irradiation.

Given that metallacage 4 possesses electron-deficient PDI faces and available cavities, we initiated an examination of its host–guest complexation with polycyclic aromatic hydrocarbons (PAHs), including pyrene (G₁) and coronene (G₂). The ¹H NMR spectra (Fig. 2a) revealed that all complexes underwent fast exchange on the NMR timescale. The protons of all the guests displayed significant upfield chemical shifts, indicating their effective host–guest complexation with metallacage 4. The association constants (K_a) of 4⊃G₁ and 4⊃G₂ in CD₃CN (Figs. 2c, S12 and S13) were determined to be (2.63 ± 0.05) × 10³ and (1.41 ± 0.07) × 10⁴ M^− 1, respectively. Encouraged by these results, the encapsulation of four typical industrial polluted dyes, including alizarin red S (G₃), methyl orange (G₄), methylene blue (G₅), rhodamine B (G₆) by 4 was then studied (Fig. 2a). After the addition of two negatively charged dyes G₃ and G₄, the protons of G₃ and G₄ exhibited notable upfield shifts due to the shielding effect of 4, indicating an obvious host − guest complexation. As for the positively charged dyes G₅ and G₆, lots of unidentifiable peaks were found in ¹H NMR spectra after complexation, and extra undistinguishable peaks were observed in the ³¹P{¹H} NMR spectra (Fig. 2b). This result suggested the metallacage was destroyed by the addition of G₅ and G₆, because the chloride ions of G₅ and G₆ broke the metal-coordination bonds of 4, which was also observed in other supramolecular coodination systems.^{[56, 57]} The K_a of 4⊃G₃ and 4⊃G₄ in CD₃CN were determined to be (9.24 ± 0.27) × 10⁴ and (6.62 ± 0.32) × 10⁴ M^− 1, respectively (Figs. 2c, S16 and S17).

The metallacage-crosslinked supramolecular networks 6a, 6b and 6c were prepared via photo-induced copolymerization of metallacage 4 and butyl methacrylate. The weight percentages of metallacage 4 in 6a, 6b and 6c were adjusted to 1%, 3%, and 6%, respectively. The pure poly(butyl methacrylate) 7 (no metallacages were added) was also prepared using the same strategy as a control group. In the ³¹P{¹H} NMR spectra (Figs. 3a, S18a and S19a) of 6a–6c, the two doublet peaks became more and more broad as the reaction proceeded. In the ¹H NMR specta (Figs. 3b, S18b and S19b), as the photo-induced polymerization proceeded, signals at 6.01 and 5.45 ppm corresponding to the terminal alkene protons H₈ and H₉ of butyl methacrylate gradually disappeared, suggesting the successful copolymerization between metallacage 4 and butyl methacrylate. The protons corresponding to the metallacages remained nearly unchanged in the networks, indicating that the metallacage structures are well-preserved in the polymers. The morphology of the supramolecular networks was examined by their optical, fluorescent photographs and scanning electron microscopy (SEM). Orange, free-standing films with yellow emission were found for all the networks (Figs. 3c and S20). SEM analysis indicated that the networks displayed a continuous architecture with smooth surface and a ~ 1 mm cross-section height (Figs. 3d and S21). Moreover, elements of C, O, N and Pt were all detected (Figs. 3f, S22 and S23) and distributed uniformly in networks 6a, 6b and 6c by the EDS analysis (Figs. 3e, S24 and S25).

It has been recognized that PDI ligand 1 can act as a photosensitizer capable of producing singlet oxygen (¹O₂) under light irradiation.^{[58, 59]} To investigate the generation of ¹O₂ through photosensitization by metallacage 4, network 6c and polymer 7, electron spin resonance (ESR) spectroscopy was employed, using 2,2,6,6-tetramethylpiperidine (TEMP) as a ¹O₂ sensor. TEMP generates a stable tetramethylpiperidine oxide radical (TEMPO) upon trapping ¹O₂. The results showed that both 4 and 6c exhibited a 1:1:1 triplet signal upon light irradiation (Fig. 3g), which was consistent with the ¹O₂ signal generated by the complexes. By contrast, no obvious signals were observed for 7, indicating that metallacage 4 plays an important role in the generation of ¹O₂. The ¹O₂ generation quantum yields of 1 and 4 were further evaluated using a reactive ¹O₂ scavenger, 1,3-diphenylisobenzofuran (DPBF) (Figure S26). The absorption bands corresponding to 1 and 4 remained nearly unchanged upon photo-irridiation, suggesting their good photostability. The ¹O₂ quantum yields (Φ_Δ) of all the compounds were calculated using Rose Bengal (RB) with a known efficiency (Φ_ΔRB = 0.54) as the reference. The Φ_Δ values were determined to be 0.15 and 0.16 for 1 and 4, respectively (Fig. 3h). It is noteworthy that, due to the relatively low content of metallacages in the networks, the Φ_Δ of 6a and 6b were only 0.07 and 0.12, respectively. After increasing the content of 4, the Φ_Δ of 6c rose to 0.16. In contrast, polymer 7 without metallacages did not generate ¹O₂. These results demonstrate that the metallacage-crosslinked networks still effectively retain the ¹O₂ generation ability of the metallacages.

Chemicals and microorganisms, especially dyes and bacteria are the most aboundant sources of water pollution. It has been widely recognized that dyes can be effectively degraded by the photo-oxidation reactions catalyzed by ¹O₂.^[60–62] In addition, ¹O₂ can cause severe irreversible damage to a wide range of bacteria.^[63–65] Although PDI-based metallacages can generate ¹O₂ to degrade dyes and kill bacteria, their limited stability and processability prevent their practical applications as photocatalysts in water treatment. The integration of metallacages into metallacage-crosslinked supramolecular networks can increase the stability and processability of metallacages, offering a type of heterogeneous polymeric photocatalysts for water decontamination.

The photocatalytic oxidation degradation of dyes by supramolecular networks 6a–6c was first explored. Four typical industrial pollutants, G₃, G₄, G₅ and G₆ were used to determine the photocatalytic efficiency of 6a, 6b and 6c. Since the dyes tend to undergo certain self-degradation in aqueous solution, an adsorption-desorption equilibrium test was first conducted in the dark to ensure that the solution reached a relatively stable state before photocatalytic degradation. The results indicated that all these dyes reached equillubrium after 60 min in aqueous solution (Figure S27), which were then used as the samples for examining the photocatalytic efficiency. The weight of the supramolecular networks was kept the same for better comparison. Taking 6c for example, the color of the solutions gradually faded as the increase of irradiation time (λ_ex = 520 nm, Figures S28). In the UV/vis absorption spectra of 6c with different dyes, all the dyes experienced a remarkable decreased in absorption intensity (Figs. 4a-4d). Similar trends were also observed for other samples (Figures S29a-S29d, S30a-S30d and S31a-S31d). For all networks, G₅ showed the highest degradation efficiency after photo-irridiation, while G₆ exhibited the lowest degradation efficiency (Figures S30e, S31e and S32). The degradation rate constants (Figs. 4f) of 6a, 6b and 6c were calculated from the according kinetic curves (Figs. 4e, S30f and S31f). The photodegradation performance of the supramolecular networks followed the order: 6c > 6b > 6a, which was consistent with the density of the metallacage crosslinkers in the networks. For instance, the degradation percentages of G₅ by 6a, 6b and 6c after 80 min were 68.72%, 73.44% and 77.32%, respectively (Fig. 4g) (Each experiment was repeated three times, and the average value is taken). However, this value of metallacage 4 was only 40.31% owing to its destruction after the addition of G₅ (Figures S29e and S29f). After photo-induced copolymerization, the resulting networks effectively protect the structure of the metallacages, serving as a type of heterogeneous photocatalysts for dye degradation. Furthermore, these networks could be reused for at least five cycles without obvious decrease in photocatalytic performance (Fig. 4h), revealing its good stability and recyclability.

To further promote the application of these supramolecular networks in water decontamination, their photodynamic antibacterial properties were also investigated. In vitro antibacterial activities of 6a–6c against Gram-positive bacterial (S. aureus) and Gram-negative bacterial (E. coli) were systematically evaluated. Ligand 1 and 3 only showed moderate antibacterial ability upon photo-irrdiation (Figures S33a and S34a). Metallacage 4 demonstrated significantly enhanced antibacterial behavior owing to its good photosensitivity to produce ¹O₂ (Figures S33a and S34a). As the increase of the density of metallacages, grandually enhanced bactericidal effects were observed from 6a to 6c under 520 nm light irradiation. The MBC values of 6a, 6b and 6c were 2, 0.01 and 0.004 mg against S. aureus (Figs. 5a and 5b), and > 2, 0.01 and 0.032 mg against E. coli, respectively (Figure S35a). Polymer 7 displayed negligible antibacterial effect against S. aureus nor E. coli (Figure S36a), indicating that the antibacterial behaviors of these networks were derived from their metallacage crosslinkers. From these results, it can be concluded that metallacages with the capability to produce ¹O₂ endow the bactericidal activity to the resulting metallacage-crosslinked networks, and the slight increase of 4 in the networks can bring dramatical enhancement in antibacterial activities.

To get a deeper insight into the antibacterial behaviors of 6a, 6b and 6c against bacteria, SEM measurement was employed to visualize the morphological changes of S. aureus and E. coli after treatments. No obvious morphological transition of E. coli or S. aureus was found after the treatment of PBS or 6a–6c without light irradiation (Figs. 5c and S35c). By contrast, once the bacteria were cocultured with networks 6a–6c and irradiated (λ_ex = 520 nm) for 30 min, the cell membranes of the bacteria were significantly wrinkled and collapsed. From 6a to 6c, the damaged cell percentage gradually increased after treatment (Figs. 5c and S35c), which was consistent with their enhanced antibacterial activities. The generated ¹O₂ can react with the unsaturated fatty acids in the bacterial cell membrane, leading to lipid peroxidation.^[66–69] This process would disrupt the integrity of the cell membrane, causing increased permeability, leakage of cellular contents, and ultimately cell death.

In order to promote the applications of such networks in real wastewater decontamination, wastewater containing both bacteria and dyes was studied (Figs. 6a and S37). Upon irradiation (λ_ex = 520 nm) in the presence of 6c, a considerable decrease (Figures S38a and b) in the absorption of G₃ (or G₅) was observed for the aqueous solution containing both S. aureus and G₃ (or G₅), suggesting G₃ and G₅ in the mixture could be degraded efficiently. Their degradation kinetics (Figures S38c and S38d) were close to the solution containing only the dyes. 6c also possessed excellent bactericidal effects to S. aureus and E. coli in the wastewater upon light irradiation (λ_ex = 520 nm) for 30 min (Fig. 6b). As individual dyes G₃ and G₅ did not show any antibacterial abilities against S. aureus and E. coli (Figure S39), indicating the reduction of bacterial cells was only attributed to the anti-bacterial activities of the metallacages in the networks. These results revealed that the networks could cause the photodegradation of dyes and bacterial death simultaneously, indicating that they could be used as water decontamination materials in the removal of multiple pollutants. The purified water was further applied for plant growth. An aqueous solution containing all the four dyes (0.02 g/L) and the two types of bacteria (10⁸ CFU/mL) was prepared for the study. Upon photoirradiation (λ_ex = 520 nm) for 30 min in the presence of 6c, the color of the solution changed from brown to light red (Fig. 6c). The average height of the plants cultivated with purified water was approximately 25 cm after 7 days (Fig. 6d), which was noticeably higher and more vigorous than those cultivated with wastewater (height of ca. 18 cm). The root growth of the plants cultivated with wastewater before and after treatment on the fourth and seventh day was also studied (Fig. 6e). On the fourth day, the roots of the purified water group were long and robust, whereas those of the wastewater group were short and thin. After seven days of growth, the roots of the purified water group remained more developed than those of the wastewater group. These results indicated that bacteria and dyes might cause root rot or introduce toxic substances to the plants and thus inhibited their growth. The purified water provided a cleaner environment for the plants, which effectively promoted the root development and nutrient absorption. In order to verify the stability of the networks, the ¹H and ³¹P{¹H} NMR spectra of 6c (Figures S41a and S41b) after wastewater decontamination was collected. It can be seen from the spectra that although the intensity of the peaks slightly decreased, the location of the peaks and their shape were consistent with their original results, indicating that the metallacages inside the networks were intact even after water decontamination.

In summary, an acrylate, PDI-based metallacage was prepared and ultilized to construct metallacage-crosslinked supramolecular networks based on photo-induced copolymerization. This strategy greatly increased the stability and processability of the metallacages, while their photosensitivity was well retained in the networks. Therefore, the supramolecular networks were used as heterogeneous photocatalysts for the degradation of dyes and bacterial disinfection owing to its good ¹O₂ generation generation ability. After treatment, the water quality was remarkably improved for plant irrigation and growth, suggesting the good performance of these networks for water decontamination. This study provides an efficient photopolymerization strategy to prepare free-standing supramolecular networks and explores their applications for water decontamination, which significantly contributes to the advancement of metallacage-based networks as photocatalytic functional materials.

Synthesis of Metallacage 4

Compounds 1, 2 and 3 (in a 1:1:4 molar ratio) were dissolved in acetone/water (10 mL, 4:1, v/v). The whole reaction mixture was heated at 60°C for 8 hours and then cooled to room temperature. The solvent was removed by nitrogen flow. The residue was redissolved in acetonitrile and filtered, then treated with diethyl ether to obtain precipitation. The resulting product was collected via centrifugation, yielding metallacage 4 as a red powder.

Preparation of networks 6a–6c and polymer 7

Metallacage 4 (0.002 g) was suspended in butyl methacrylate (BMA, 0.200 g) and stirred for 30 minutes. Photoinitiator 2,2-Dimethoxy-2-phenylacetophenone (DMPA) was then added to the mixture at a concentration of 1 wt% relative to the total weight of the monomers, and the mixture was stirred for additional 5 min. The resulting suspension was poured into a Teflon mold and photopolymerized under a UV lamp for 8 hours to produce network 6a with a 1 wt% metallacage loading. The distance between the mold and the UV light source was set to 5 cm. Networks 6b and 6c, with metallacage loadings of 3 wt% and 6 wt%, respectively, and polymer 7 (without metallacages) were prepared using the same procedure.

Acknowledgements

This work was supported by the National Natural Science Foundation of China (22171219, 22222112, 22301238 and 22101227), Shaanxi Fundamental Science Research Project for Chemistry and Biology (23JHQ016), Innovation Talent Promotion Plan of Shaanxi Province for Science and Technology Innovation Team (2023-CX-TD-51), and the Interdisciplinary Training Program for Doctoral Candidate of Xi’an Jiaotong University (IDT2105). We thank Dr. Gang Chang and Dan He at Instrument Analysis Center and Dr. Aqun Zheng and Junjie Zhang at Experimental Chemistry Center of Xi’an Jiaotong University for NMR and fluorescence measurements. We thank Menghan Sun from Shiyanjia Lab (www.shiyanjia.com) for the X-ray crystal structure and ESR analysis. We also acknowledge the mass spectrometry characterization provided by the members of Molecular Scale Lab at Shenzhen University.

Contributions

M. Z., L.G and D. C. conceived and directed the project. R. L. synthesized the compounds, performed the photodegradation experiments and wrote the manuscript. H. Z. performed the antibacterial experiment studies. Y. H. helped in data analyses. All authors discussed the results and commented on the manuscript.

Ethics declarations

Competing interests

The authors declare no competing financial interest.

Li, W. W., Yu, H. Q. & Rittmann, B. E. Chemistry: reuse water pollutants. Nature528, 29-31 (2015).
Wang, M. et al. Accounting for interactions between sustainable development goals is essential for water pollution control in China. Nat. Commun. 13, 730 (2022).
Ali, I. & Gupta, V. K. Advances in water treatment by adsorption technology. Nat. Protoc.1, 2661-2667 (2006).
Shen, Y., Fang, Q. & Chen, B. Environmental applications of three-dimensional graphene-based macrostructures: adsorption, transformation, and detection. Environ. Sci & Technol.49, 67-84 (2015).
Xie, S. et al. Intelligent mesoporous materials for selective adsorption and mechanical release of organic pollutants from water. Adv. Mater. 30, 1800683 (2018).
Madsen, E. L. Determining in situ biodegradation. Environ. Sci & Technol. 25, 1662-1673 (1991).
Yu, M. L. et al. Intimate coupling of photocatalysis and biodegradation for wastewater treatment: mechanisms, recent advances and environmental applications. Water Res. 175, 115673 (2020).
Sheridan, E. A. et al. Plastic pollution fosters more microbial growth in lakes than natural organic matter. Nat. Commun. 13, 4175 (2022).
Yu, G. F., Wang, Y. X., Cao, H. B., Zhao, H. & Xie, Y. B. Reactive oxygen species and catalytic active sites in heterogeneous catalytic ozonation for water purification. Environ. Sci & Technol. 54, 5931-5946 (2020).
Sungeun, L., Jiaming, L. S., Urs, von G. & Daniel, L. M. Ozonation of organic compounds in water and wastewater: A critical review. Water Res. 213, 118053 (2022).
Martínez-Huitle, C. A., Rodrigo, M. A., Sirés I. & Scialdone, O. Single and coupled electrochemical processes and reactors for the abatement of organic water pollutants: a critical review. Chem. Rev. 115, 13362-13407 (2015).
Hodges, B. C., Cates, E. L. & Kim, J. H. Challenges and prospects of advanced oxidation water treatment processes using catalytic nanomaterials. Nat. Nanotechnol.13, 642-650 (2018).
Xia, C. et al. Confined local oxygen gas promotes electrochemical water oxidation to hydrogen peroxide. Nat. Catal. 3, 125-134 (2020).
Barac, T. et al. Engineered endophytic bacteria improve phytoremediation of water-soluble, volatile, organic pollutants. Nat. Biotechnol. 22, 583-588 (2004).
Jeevanantham, S. et al. Removal of toxic pollutants from water environment by phytoremediation: a survey on application and future prospects. Environ. Sci & Technol. 13, 264-276 (2019).
Mills, A., Davies, R. H. & Worsley, D. Water purification by semiconductor photocatalysis. Chem. Soc. Rev. 22, 417-425 (1993).
Marin, M. L., Santos-Juanes, L., Arques, A., Amat, A. M. & Miranda, M. A. Organic photocatalysts for the oxidation of pollutants and model compounds. Chem. Rev. 112, 1710-1750 (2012).
Li, X., Yu, J. & Jaroniec, M. Hierarchical photocatalysts. Chem. Soc. Rev. 45, 2603-2636 (2016).
Tao, X. P., Zhao, Y., Wang, S. Y., Li, C. & Li, R. G. Recent advances and perspectives for solar-driven water splitting using particulate photocatalysts. Chem. Soc. Rev. 51, 3561-3608 (2022).
Mondal, B. & Mukherjee, P. S. Cage encapsulated gold nanoparticles as heterogeneous photocatalyst for facile and selective reduction of nitroarenes to azo compounds. J. Am. Chem. Soc.140, 12592-12601 (2018).
Yu, F. Y., Jing, X., Wang, Y., Sun, M. Y. & Duan, C. Y. Hierarchically porous metal-organic framework/MoS₂ interface for selective photocatalytic conversion of CO₂ with H₂O into CH₃COOH. Angew. Chem. Int. Ed.60, 24849-24853 (2021).
Li, W. J. et al. Artificial light-harvesting systems based on AIEgen-branched rotaxane dendrimers for efficient photocatalysis. Angew. Chem. Int. Ed.133, 18909-18916 (2021).
Bokotial, D., Acharyya. K., Chowdhury, A. & Mukherjee, P. S. Pt (II)/Pd (II)-based metallosupramolecular architectures as light harvesting systems and their applications. Angew. Chem. Int. Ed.63, e202401136 (2024).
Lettmann, C., Hinrichs, H. & Maier, W. F. Combinatorial discovery of new photocatalysts for water purification with visible light. Angew. Chem. Int. Ed.40, 3160-3164 (2001).
Zhang, T. & Lin, W. Metal-organic frameworks for artificial photosynthesis and photocatalysis. Chem. Soc. Rev. 43, 5982-5993 (2014).
Fan, Y. et al. Convenient recycling of 3D AgX/graphene aerogels (X = Br, Cl) for efficient photocatalytic degradation of water pollutants. Adv. Mater.27, 3767-3773 (2015).
Hu, W., Lin, L., Zhang, R. Q., Yang, C. & Yang, J. L. Highly efficient photocatalytic water splitting over edge-modified phosphorene nanoribbons. J. Am. Chem. Soc.139, 15429-15436 (2017).
Pan, L. et al. Manipulating spin polarization of titanium dioxide for efficient photocatalysis. Nat. Commun.11, 418 (2020).
Song, R. et al. Highly efficient degradation of persistent pollutants with 3D nanocone TiO₂-based photoelectrocatalysis. J. Am. Chem. Soc.143, 13664-13674 (2021).
Huang, C. F. et al. Unraveling fundamental active units in carbon nitride for photocatalytic oxidation reactions. Nat. Commun.12, 320 (2021).
Sprick, R. S. et al. Visible-light-driven hydrogen evolution using planarized conjugated polymer photocatalysts. Angew. Chem. Int. Ed.55, 1792-1796 (2016).
Corrigan, N., Shanmugam, S., Xu, J. T. & Boyer, C. Photocatalysis in organic and polymer synthesis. Chem. Soc. Rev.45, 6165-6212 (2016).
Zhu, Y., Zheng, W., Wang, W. & Yang, H. B. When polymerization meets coordination-driven self-assembly: metallo-supramolecular polymers based on supramolecular coordination complexes. Chem. Soc. Rev.50, 7395-7417 (2021).
Li, G. F. et al. Robust and dynamic polymer networks enabled by woven crosslinks. Angew. Chem. Int. Ed.134, e202210078 (2022).
Zhang, Z. M. et al. Mechanically interlocked networks cross-linked by a molecular necklace. Nat. Commun.13, 1393 (2022).
Huang, H. L., Jing, X., Deng, J. T., Meng, C. G. & Duan, C. Y. Enzyme-inspired coordination polymers for selective oxidization of C(sp³)−H bonds via multiphoton excitation. J. Am. Chem. Soc. 145, 2170-2182 (2023).
Chakrabarty, R., Mukherjee P. S., & Stang, P. J. Supramolecular coordination: self-assembly of finite two-and three-dimensional ensembles. Chem. Rev. 111, 6810-6918 (2011).
Sun, Y., Chen, C., Liu, J. & Stang, P.J. Recent developments in the construction and applications of platinum-based metallacycles and metallacages via coordination. Chem. Soc. Rev. 49, 3889-3919 (2020).
Lisboa, L. S. et al. Heterotrimetallic double cavity cages: syntheses and selective guest binding. Angew. Chem. Int. Ed.61, e202201700 (2022).
Wei, Z. et al. A platinum (II)-based molecular cage with aggregation-induced emission for enzymatic photocyclization of alkynylaniline. Angew. Chem. Int. Ed. 62, e202214577 (2023).
Banerjee, R., Chakraborty, D. & Mukherjee, P. S. Molecular barrels as potential hosts: from synthesis to applications. J. Am. Chem. Soc. 145, 7692-7711 (2023).
Moree, L. K., Faulkner, L. A. V. & Crowley, J. D. Heterometallic cages: synthesis and applications. Chem. Soc. Rev.53, 25-46 (2024).
Hou, Y. L. et al. Perylene diimide-based multicomponent metallacages as photosensitizers for visible light-driven photocatalytic oxidation reaction. CCS Chemistry. 4, 2604-2611 (2022).
Mu, C. Q. et al. Isoreticular preparation of tetraphenylethylene-based multicomponent metallacages towards light-driven hydrogen production. Angew. Chem. Int. Ed.135, e202311137 (2023).
Liu, D. D. et al. Molecular co-catalyst confined within a metallacage for enhanced photocatalytic CO₂ reduction. J. Am. Chem. Soc. 146, 2275-2285 (2024).
Gao, K. et al. Guest-regulated generation of reactive oxygen species from porphyrin-based multicomponent metallacages for selective photocatalysis. Angew. Chem. Int. Ed.136, e202319488 (2024).
Lu, C. J. et al. Fluorescent metallacage-core supramolecular polymer gel formed by orthogonal metal coordination and host–guest interactions. J. Am. Chem. Soc. 140, 7674-7680 (2018).
Zhang, Z. M. et al. Muscle-mimetic synergistic covalent and supramolecular polymers: phototriggered formation leads to mechanical performance boost. J. Am. Chem. Soc. 143, 902-911 (2020).
Zhu, Y., Zheng, W., Wang, W. & Yang H. B. When polymerization meets coordination-driven self-assembly: metallo-supramolecular polymers based on supramolecular coordination complexes. Chem. Soc. Rev.50, 7395-7417 (2021).
Gao, K. et al. Emissive metallacage-cored polyurethanes with self-healing and shape memory properties. Angew. Chem. Int. Ed. 134, e202209958 (2022).
Lin, H. Y., Wang, Y. T., Shi, X. L., Yang, H. B. & Xu, L. Switchable metallacycles and metallacages. Chem. Soc. Rev.52, 1129-1154 (2023).
Zhang, R. Q. et al. Metallacycle/metallacage-cored supramolecular networks. Prog. Polym. Sci. 141, 101680 (2023).
Gao, K. et al. Porphyrin-metallacage-crosslinked s upramolecular network for visible-light-driven heterogeneous photocatalysis. Cell Rep. Phys. Sci. 4, 101655 (2023).
Hou, T. L. et al. Highly emissive perylene diimide-based mmetallacages and their host−guest chemistry for information encryption. J. Am. Chem. Soc.142, 18763-18768 (2020).
Li, R. R. et al. Enhancing the photosensitivity of hypocrellin A by perylene diimide metallacage-based host–guest complexation for photodynamic therapy. Nano-Micro Lett. 16, 226 (2024).
Benchimol, E., Nguyen, B. N. T., Ronson, T. K. & Nitschke, J. R. Transformation networks of metal-organic cages controlled by chemical stimuli. Chem. Soc. Rev.51, 5101-5135 (2022).
Zhang, Z. M. et al. Mechanically interlocked networks cross-linked by a molecular necklace. Nat. Commun.13, 1393 (2022).
Würthner, F. et al. Perylene bisimide dye assemblies as archetype functional supramolecular materials. Chem. Rev. 116, 962-1052 (2016).
Teng, K. X., Niu, L. Y. & Yang, Q. Z. Supramolecular photosensitizer enables oxygen-independent generation of hydroxyl radicals for photodynamic therapy. J. Am. Chem. Soc. 145, 4081-4087 (2023).
Zhang, M., Chen, C. C., Ma, W. H. & Zhao, J. C. Visible-light-induced aerobic oxidation of alcohols in a coupled photocatalytic system of dye-sensitized TiO₂ and TEMPO. Angew. Chem. Int. Ed.120, 9876-9879 (2008).
Mushtaq, F. et al. Magnetoelectrically driven catalytic degradation of organics. Adv. Mater.31, 1901378 (2019).
Routoula, E. & Patwardhan, S. V. Degradation of anthraquinone dyes from effluents: a review focusing on enzymatic dye degradation with industrial potential. Environ. Sci & Technol.54, 647-664 (2020).
Macia, N., Bresoli-Obach, R., Nonell, S. & Heyne, B. Hybrid silver nanocubes for improved plasmon-enhanced singlet oxygen production and inactivation of bacteria. J. Am. Chem. Soc. 141, 684-692 (2018).
Xu, Y. L. et al. Design of a metallacycle-based supramolecular photosensitizer for in vivo image-guided photodynamic inactivation of bacteria. Angew. Chem. Int. Ed.134, e202110048 (2022).
Xu, Y. L. et al. De novo designed Ru (II) metallacycle as a microenvironment-adaptive sonosensitizer and sonocatalyst for multidrug-resistant biofilms eradication. Angew. Chem. Int. Ed.136, e202319966 (2024).
Planas, O., Macia, N., Agut, M., Nonell, S. & Heyne, B. Distance-dependent plasmon-enhanced singlet oxygen production and emission for bacterial inactivation. J. Am. Chem. Soc.138, 2762-2768 (2016).
Wu, G. Y. et al. Efficient self-assembly of heterometallic triangular necklace with strong antibacterial activity. Nat. Commun.11, 3178 (2020).
Gao, F., Shao, T. Y., Yu, Y. P., Xiong, Y. J. & Yang, L. H. Surface-bound reactive oxygen species generating nanozymes for selective antibacterial action. Nat. Commun.12, 745 (2021).
Xu, Y. L. et al. Design of a metallacycle-based supramolecular photosensitizer for in vivo image-guided photodynamic inactivation of bacteria. Angew. Chem. Int. Ed.134, e202110048 (2022).

Scheme 1 is available in the Supplementary Files section.

There is NO Competing Interest.

Download PDF

Version 1

posted

You are reading this latest preprint version

Metallacage-Crosslinked Free-Standing Supramolecular Networks via Photo-induced Copolymerization for Photocatalytic Water Decontamination

Status:

Version 1

Abstract

Figures

Introduction

Results and Discussion

Conclusion

Methods

Synthesis of Metallacage 4

Preparation of networks 6a–6c and polymer 7

Declarations

References

Scheme

Additional Declarations

Supplementary Files

Status:

Version 1