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Construction and confocal fluorescence microscopy images of LP–HER-WOR-MOF a, Assembling the hydrophobically modified HER-MOF with lecithin/cholesterol/TCBQ gave a bilayer film on a glass surface after solvent removal, which was hydrated and sonicated to form vesicles that wrap a fraction of WOR-MOF and Fe³⁺ in the aqueous phase; the mixture was then pushed through an extruder (1 µm) to reshape large liposomes and remove most of the unwrapped WOR-MOFs that aggregated into particles larger than the pore size. b,d,f, Confocal fluorescence microscopy images of LP–HER-WOR-MOF at different excitation wavelengths. Emissions were collected in the wavelength range of 600–700 nm: red represents HER-MOF + WOR-MOF and green represents WOR-MOF, whereas overlay of green and red gives a yellow colour to represent the overlap of the two MOFs. There is a thin shell of the liposome containing HER-MOF but not WOR-MOF, consistent with distribution of HER-MOF in the bilayer and WOR-MOF in the inner cavity. c,e,g, Higher resolution confocal images of the LP–HER-WOR-MOF at different excitation wavelengths. h, TEM image of the LP–HER-WOR-MOF showing WOR-MOF as small dark dots inside the liposome. i, Schematic of the LP–HER-WOR-MOF showing HER-MOF as green blocks within the lipid bilayer and marking the space containing WOR-MOF as the blue area. j, Excitation spectra of HER-MOF and WOR-MOF. Source data
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Metal–organic frameworks (MOFs) have been studied extensively in the hydrogen evolution reaction (HER) and the water oxidation reaction (WOR) with sacrificial reagents, but overall photocatalytic water splitting using MOFs has remained challenging, principally because of the fast recombination of photo-generated electrons and holes. Here we have in...
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... 8 Metal-Organic frameworks (MOFs) are well-known for the highly designable, tunable structures and pore surfaces, and have been applied in diverse elds, 9 including catalytic oxidation. [10][11][12] However, the application of pure MOFs for degrading antibiotics in AOPs is rarely reported, while the majority focus is on the degradation of dyes. For example, [Fe 3 O(TBA) 3 (OH)(H 2 O) 2 ] (MIL-88A(Fe), H 2 TBA = trans-2-butenedioic acid) and defective [Fe 3 O(ATA) 3 (OH)(H 2 O) 2 ] (MIL-88B(NH 2 )(Fe), H 2 NBDC = 2-amino-1,4-benzene dicarboxylic acid) have been reported as catalysts, achieving more than 90% degradation of tetracycline (TC) and sulfamethoxazole (SMX) via activating the oxidants, demonstrating that the open metal sites (OMSs) are more conducive to the activation of PMS. ...
Highly efficient degradation of antibiotics is a huge challenge due to the extremely stable molecules and the potential for biological resistance. However, conventional degradation methods are limited to lower degradation rate, higher energy consumption and secondary pollution. Herein, we report a new Cu-based metal–organic framework (MOF), featuring classical planar trinuclear [Cu3(µ3-O)]⁴⁺ clusters within the pores. The presence of the rich open metal sites and the large pore ratio, as well as the high catalytic activity of Cu²⁺ ions, are conducive to boosting the degradation of various antibiotics (>95%) under the activation of peroxymonosulfate. Remarkably, this is the first MOF to achieve such exceptional catalytic performance under neutral and even alkaline conditions, which exceeds those of most reported materials. Mechanism investigation demonstrates that multiple active species were produced and promoted the degradation synergistically during the advanced oxidation processes.
... Traditional OECs often exhibited illdefined structures undesirable for mechanistic studies. Fortunately, metal-organic frameworks (MOFs) with well-defined crystal structures [24,25] and abundant exposed active sites [26][27][28] are ideal for investigating the intrinsic structure and catalytic activity relationship [29][30][31]. Up to date, several researchers developed MOF materials decorated photoelectrode, such as MOF-BiVO 4 , to improve PEC-OER activity; however, their conductivity and catalytic stability are invariably unsatisfied. ...
Metal–organic frameworks (MOFs) have been developed as an ideal platform for exploration of the relationship between intrinsic structure and catalytic activity, but the limited catalytic activity and stability has hampered their practical use in water splitting. Herein, we develop a bond length adjustment strategy for optimizing naphthalene-based MOFs that synthesized by acid etching Co-naphthalenedicarboxylic acid-based MOFs (donated as AE-CoNDA) to serve as efficient catalyst for water splitting. AE-CoNDA exhibits a low overpotential of 260 mV to reach 10 mA cm ⁻² and a small Tafel slope of 62 mV dec ⁻¹ with excellent stability over 100 h. After integrated AE-CoNDA onto BiVO 4 , photocurrent density of 4.3 mA cm ⁻² is achieved at 1.23 V. Experimental investigations demonstrate that the stretched Co–O bond length was found to optimize the orbitals hybridization of Co 3 d and O 2 p , which accounts for the fast kinetics and high activity. Theoretical calculations reveal that the stretched Co–O bond length strengthens the adsorption of oxygen-contained intermediates at the Co active sites for highly efficient water splitting.
... The aforementioned, modified aluminium-doped strontium titanate presents an AQY of 56% at 365 nm, and due to the broad visible light absorption, a PMOF-based system has been reported to perform OWS with an AQY of 1.5% at 436 nm. 53 Turnover number (TON) and turnover frequency (TOF) values are also sometimes provided in the reports. The TON refers to the number of moles of substrate reacting per number of moles of the active sites in a catalyst, while the TOF measures this ratio over a certain time. ...
... In the seminal contribution, the integration of two types of MOFs nanosheetsa HER-MOF and a water oxidation reaction (WOR)-MOF in a liposome structurewas adapted as a strategy to separate the generated charges and related half-reactions for the OWS. 53 The integrated HER-MOF nanosheets are based on Hf 6 clusters and metalloporphyrins with the chemical composition: [Hf 6 (μ 3 -O) 4 (μ 3 -OH) 4 (μ 1 -OH) 2 (μ 1 -H 2 O) 2 (HCO 2 ) 6 [(TCPP)Zn] 1−x [(TCPP)Pt] x ]. In its structure two types of metalloporphyrin are present, the light-harvesting Znporphyrin and catalytic Pt-porphyrin. ...
This review aims to provide a thorough summary of the versatile applications of porphyrin-based metal-organic frameworks (PMOFs) as photocatalysts in an aqueous environment, specifically focusing on the production of solar fuels and the degradation of pollutants. The first section describes the fundamental attributes of porphyrin molecules as building units of stable PMOFs, efficient in photocatalysis under solar light irradiation in water. Key considerations, such as their light absorption and photophysical properties, are discussed, and the structures of several representative PMOFs are detailed. The subsequent section highlights the utilization of PMOFs and composites for the photocatalytic hydrogen evolution reaction in the presence of sacrificial electron donors as well as for the overall water splitting into H 2 and O 2. The third section focuses on the versatile utilizations of PMOFs and composites in the photodegradation of different kinds of emerging organic pollutant, showing their potential for environmental remediation. Finally, this review summarizes the current state-of-the art of the field together with proposing insights into the future prospects and opportunities to reach more efficient materials to advance into the development of practical applications. A. Introduction Porphyrins are tetrapyrrolic macrocycles where four pyrrole rings are linked by methyne bridges and, along with related compounds (corrins, chlorins), they represent an important class of molecules that are involved in life-essential processes such as breathing, photosynthesis and detoxification. 1,2 The most common examples in biology are undoubtfully heme and chlorophylls. The former is a ferrous protoporphyrin responsible for oxygen transport in haemoglobin, while the latter represents a class of pigments found in plants (usually magnesium complexes) enabling photosynthesis. There are also less common examples of naturally occurring porphyrins whose roles are still being investigated, such as bird feather pigments. 3,4 The key functions fulfilled by the porphyrinic molecules are enabled due to their unique structure and intrinsic properties. The aromaticity (18 conjugated π electrons) leads to strong visible light absorption and enhanced stability. Moreover, the ability to chelate various metal ions allows metalloporphyrin to bind and transport small molecules as well as perform redox processes. Historically, complex unsymmetrical porphyrins that are naturally available were first discovered, structurally characterized and their synthesis attempted. Later, simpler octaethyl (bearing substituents on the β-pyrrolic positions) and tetraphe-nyl (bearing substituents at the methyne bridge meso positions) porphyrins were developed, leading to significant advancements in their chemical synthesis. As a result, on-demand functionalized molecules became accessible in terms of their increased-scale production and commercialization (examples of vendors: TCI chemicals®, Sigma-Aldrich®, Porphychem®). This progress greatly contributed to the development of porphyrin-based materials and devices, including metal-organic frameworks (MOFs). MOFs are appealing materials as they combine the intrinsic properties of porphyr-ins with their nanoscale structuring into a porous network, leading to high surface areas and accessibility of porphyrinic
... The afore-mentioned, modified aluminium doped strontium titanate presents an AQY of 56% at 365 nm, when for MOFs the AQYs remain below 10%, and due to the strong visible light absorption, a PMOFbased system has been reported to perform OWS with a AQY of 1.5% at 436 nm. 53 Turnover number (TON) and turnover frequency (TOF) values are also sometimes provided in the reports. The TON refers to the number of moles of substrate reacting per number of moles of the active sites in a catalyst, while TOF measures this ratio over a certain time. ...
... In the seminal contribution, the integration of two types of MOFs nanosheets: a HER-MOF and a Water Oxidation Reaction WOR-MOF in a liposome structure was adapted as a strategy to separate the generated charges and related half reactions for the OWS. 53 The integrated HER-MOF nanosheets are based on Hf6 clusters and metalloporphyrins with the chemical composition: ...
This review aims to provide a thorough summary of the versatile applications of porphyrin-based metal-organic frameworks (PMOFs) as photocatalysts in aqueous environment, specifically focusing on the production of solar fuels...
... In this study, we utilized the widely recognized potassium ferrioxalate actinometer (Reaction 1), 11,20,41,42 of which the quantum yield has been explored across an extensive wavelength range. 43 We employed several pseudo-monochromatic UV-A LED light sources, and their spectral distributions were determined using a spectrophotometer (Supplementary Figure S4a). ...
Photocatalysis for small molecule activation has seen significant advancements over the past decade, yet its scale-up remains a challenge due to photon attenuation effects. A promising solution lies in harnessing high photonic intensities paired with continuous-flow reactor technology. However, a deep grasp of photon transport is essential, typically demanding resource-intensive experiments. To address this, we introduce an innovative approach to photochemical reactor setup characterization, starting with radiometric light source analysis and progressing to a 3D reactor simulation for photon flux determination. Contrary to conventional techniques that prioritize complete photon absorption, our technique operates optimally when the reaction mixture is unsaturated. This strategy decouples photon flux and path length determination, substantially curtailing the experimental process. The workflow proves versatile across various reactor systems, simplifying intricate light interactions into a single one-dimensional parameter, i.e., the effective optical path length. Combined with the photon flux, this parameter effectively characterizes photochemical setups, irrespective of scale, geometry, light intensity, or photocatalyst concentration. Employing radiometry further offers insights into light source positioning and reactor design, and obviates the need for repeated chemical actinometry measurements due to light source degradation. Additionally, the proposed workflow facilitates experiments at lower concentrations, ensuring optimal reactor operation. In essence, our approach provides a thorough, efficient, and consistent framework for reactor irradiation characterization.
... The system achieved almost a 5-fold higher activity (1456 TON CO) and 7-fold selectivity (77%) for CO 2 R to CO compared to the homogeneous non-alkylated analogous system, revealing an enhanced performance thanks to the self-assembly. Mechanistic studies demonstrated that the grater performance is due to a 2-fold increased charge-separation state lifetime of the PS, allowing for a 9-fold faster electron transfer to the CoPc in the liposome 93 3 Cl to form the active catalytic species 137 . Finally, more complex compartmentalized systems have been reported for CO 2 conversion, including enzymes and full biologic metabolic pathways into artificial vesicles 136,138,139 . ...
Artificial photosynthesis aims to produce fuels and chemicals from simple building blocks (i.e. water and carbon dioxide) using sunlight as energy source. Achieving effective photocatalytic systems necessitates a comprehensive understanding of the underlying mechanisms and factors that control the reactivity. This review underscores the growing interest in utilizing bioinspired artificial vesicles to develop compartmentalized photocatalytic systems. Herein, we summarize different scaffolds employed to develop artificial vesicles, and discuss recent examples where such systems are used to study pivotal processes of artificial photosynthesis, including light harvesting, charge transfer, and fuel production. These systems offer valuable lessons regarding the appropriate choice of membrane scaffolds, reaction partners and spatial arrangement to enhance photocatalytic activity, selectivity and efficiency. These studies highlight the pivotal role of the membrane to increase the stability of the immobilized reaction partners, generate a suitable local environment, and force proximity between electron donor and acceptor molecules (or catalysts and photosensitizers) to increase electron transfer rates. Overall, these findings pave the way for further development of bioinspired photocatalytic systems for compartmentalized artificial photosynthesis.
... [5,6] Vesicles with lipid bilayer membranes and embedded functional molecules were reported as model systems to perform light absorption and light-driven reactions such as H 2 generation, CO 2 reduction and water oxidation by embedding the active units at the membrane, and thereby overcome organic solvent usage and solubility problems. [7][8][9][10][11][12] In this work, the light-driven H 2 evolution reaction (HER) at lipid bilayer membranes of liposomes is reported, using the amphiphilic photosensitizer bis(2,2'-bipyridine)-(4,4'-dinonyl-2,2'-bipyridine)-ruthenium(II) (RuC 9 ), and the molybdenum sulfide cluster [Mo 3 S 13 ] 2À as HER catalyst (see Figure 1). ...
Nature uses reactive components embedded in biological membranes to perform light‐driven photosynthesis. Here, a model artificial photosynthetic system for light‐driven hydrogen (H2) evolution is reported. The system is based on liposomes where amphiphilic ruthenium trisbipyridine based photosensitizer (RuC9) and the H2 evolution reaction (HER) catalyst [Mo3S13]²⁻ are embedded in biomimetic phospholipid membranes. When DMPC was used as the main lipid of these light‐active liposomes, increased catalytic activity (TONCAT ~200) was observed compared to purely aqueous conditions. Although all tested lipid matrixes, including DMPC, DOPG, DPPC and DOPG liposomes provided similar liposomal structures according to TEM analysis, only DMPC yielded high H2 amounts. In situ scanning electrochemical microscopy (SECM) measurements using Pd microsensors revealed an induction period of around 26 minutes prior to H2 evolution, indicating an activation mechanism which might be induced by the fluid‐gel phase transition of DMPC at room temperature. Stern‐Volmer‐type quenching studies revealed that electron transfer dynamics from the excited state photosensitizer are most efficient in the DMPC lipid environment giving insight for design of artificial photosynthetic systems using lipid bilayer membranes.
... [10,11] In the field of artificial photosynthesis, great progress has been achieved for improving the catalytic efficiency of individual processes [12] or the overall efficiency of the whole system. [13][14][15] This has been achieved by the means of photocatalysis, [16][17][18] electrocatalysis, or biocatalysis, [19,20] resulting in improved regeneration of O 2 , ATP, [21][22][23][24] and NAD(P)H. [25] On the basis of these studies, the challenge of achieving multi-objective outputs in the same system is worthy of being focused. ...
The development of artificial photosynthesis systems that mimics natural photosynthesis can help address the issue of energy scarcity by efficiently utilizing solar energy. Here, it presents liposomes‐based artificial photosynthetic nanocapsules (PSNC) integrating photocatalytic, chemical catalytic, and biocatalytic systems through one‐pot method. The PSNC contains 5,10,15,20‐tetra(4‐pyridyl) cobalt‐porphyrin, tridipyridyl‐ruthenium nitrate, oligo‐pphenyl‐ethylene‐rhodium complex, and creatine kinase, efficiently generating oxygen, nicotinamide adenine dinucleotide (NADH), and adenosine triphosphate with remarkable enhancements of 231%, 30%, and 86%, compared with that of molecules mixing in aqueous solution. Additionally, the versatile PSNC enables simulation of light‐independent reactions, achieving a controllable output of various target products. The regenerated NADH within PSNC further facilitates alcohol dehydrogenase, yielding methanol with a notable efficiency improvement of 37%. This work introduces a promising platform for sustainable solar energy conversion and the simultaneous synthesis of multiple valuable products in an ingenious and straightforward way.
... However, these methods come with their own set of challenges, such as excessive space requirements, energy losses, high cost, and feasibility concerns. To address these anticipated issues, direct photocatalysis, sonophotocatalysis, and piezocatalysis have emerged as promising alternatives [4]. ...
Sonophotocatalysis has garnered significant attention due to its potential to enhance advanced oxidation processes, particularly water splitting, by employing materials with combined sonocatalytic and photocatalytic properties. In this study, we synthesized and investigated core–shell BaTiO3@SrTiO3 nanowires (BST NWs) with varying Sr/Ba molar ratios (2.5:7.5, 5.0:5.0, 7.5:2.5 mM, denoted as BST-1, BST-2, and BST-3, respectively) as catalysts for hydrogen production through water splitting. The piezoelectric nanowires demonstrated hydrogen evolution via both sonocatalysis and photocatalysis. In the sonophotocatalysis process, the ultrasonic vibration induced mechanical forces on the BST nanowires, thereby establishing a built-in electric field. This built-in electric field facilitated the effective separation of photo-generated charge carriers and prolonged their lifetimes, leading to a synergistic enhancement of hydrogen evolution. The pristine BaTiO3 and SrTiO3 nanowires exhibited relatively low hydrogen evolution rates (HER) of 7.0 and 6.0 µmol·g⁻¹min⁻¹, respectively. In contrast, the core–shell nanowires exhibited a substantial improvement in the hydrogen evolution rate. The HER increased with the addition of Sr, and BST-1, BST-2, and BST-3 achieved HERs of 12.0, 13.5, and 18.0 µmol·g⁻¹min⁻¹, respectively. The superior performance of BST-3 nanowires can be attributed to their highest piezoelectric potential and largest surface area. Additionally, BST-3 nanowires demonstrated remarkable stability over multiple cycles, validating their practical applicability as efficient photocatalysts.
... Such properties of these compounds make them a very attractive materials of potential applications in various fields, including storage and separation (Fan et al., 2021;Li et al. 2022), drug delivery (Mallakpour et al., 2022;Cao et al., 2020), catalysis Yang et al., 2021), proton conduction (Luo et al., 2019), and optical materials (Fu et al., 2020). Porous coordination polymers are also investigated as an ion exchangers and lightning harvesting materials (Hu et al., 2021;Fan et al., 2022). ...
The new three-dimensional coordination polymer termed {[Na<sub>2</sub>SDC(H<sub>2</sub>O)]}<sub>n</sub> (SDC<sup>2-</sup>= C<sub>16</sub>H<sub>10</sub>O<sub>4</sub><sup>2-</sup>) has been synthesized using workstation Easymax 102 while controlling the conditions and monitoring in-situ reagents. The metal complex was obtained in the reaction of sodium hydroxide with a suspension of 4,4’-stilbenedicarboxylic acid in aqueous medium. The compound was characterized by elemental analysis, single crystal, and powder X-ray diffraction methods, ATR-FTIR spectroscopy, SEM and optical microscopy, TG-DSC and TG-FTIR thermal analysis in air and nitrogen atmosphere. In the crystal structure of {[Na<sub>2</sub>SDC(H<sub>2</sub>O)]}<sub>n</sub> appears penta- and hexacoordinated sodium atoms joined by octa- and decadentate SDC2- linkers. Aqua ligand acts as bridge between Na1 and Na2 atoms. The as-synthesized sodium complex is thermally stable up to 86<sup>o</sup>C whereas its dehydrated form has extreme stability up to 491<sup>o</sup>C. Removal of water molecule leads to the crystal-to-crystal transformation yielded changes in coordination modes of COO groups. Reversibility of the hydration process in the studied complex was also examined.
