Graphene Quantum Dots Supported on Fe-based Metal-Organic Frameworks for Efficient Photocatalytic CO 2 Reduction ※

In recent years, metal–organic framework (MOF)-based nanofibrous membranes (NFMs) have received extensive attention in the application of water treatment. Hence, it is of great significance to realize a simple and efficient preparation strategy of MOF-based porous NFMs. Herein, we developed a direct in situ formation of MOF/polymer NFMs using an electrospinning method. The porous MOF/polymer NFMs were constructed by interconnecting mesopores in electrospun composite nanofibers using poly(vinylpolypyrrolidone) (PVP) as the sacrificial pore-forming agent. MOF (MIL-88A) particles were formed inside the polyacrylonitrile (PAN)/PVP nanofibers in situ during electrospinning, and the porous MIL-88A/PAN (pMIL-88A/PAN) NFM was obtained after removing PVP by ethanol and water washing. The MOF particles were uniformly distributed throughout the pMIL-88A/PAN NFM, showing a good porous micro-nano morphological structure of the NFM with a surface area of 143.21 m2 g−1, which is conducive to its efficient application in dye adsorption and removal. Specifically, the dye removal efficiencies of the pMIL-88A/PAN NFM for amaranth red, rhodamine B, and acid blue were as high as 99.2, 94.4, and 99.8%, respectively. In addition, the NFM still showed over 80% dye removal efficiencies after five adsorption cycles. The pMIL-88A/PAN NFM also presented high adsorption capacities, fast adsorption kinetics, and high cycling stabilities during the processes of dye adsorption and removal. Overall, this work demonstrates that the in situ electrospun porous MOF/polymer NFMs present promising application potential in water treatment for organic dyestuff removal.

Section: Introductionmentioning

confidence: 99%

In Situ Electrospun Porous MIL-88A/PAN Nanofibrous Membranes for Efficient Removal of Organic Dyes

Jia

et al. 2023

“…Metal-organic frameworks (MOFs), assembled by inorganic metal ions or clusters and organic ligands through coordination bonds, are a new kind of material with high porosity, high specific surface area, and easily adjustable structures [ 25 , 26 , 27 , 28 , 29 , 30 ]. With those excellent properties, MOFs had been widely used in many fields, such as gas adsorption and separation, drug loading, catalysis and so on [ 31 , 32 , 33 , 34 , 35 , 36 , 37 , 38 ]. Especially, strong CO 2 enrichment ability makes MOFs to be potential photocatalysts for CO 2 conversion [ 39 ].…”

Section: Introductionmentioning

confidence: 99%

“…The following supporting information can be downloaded at: , References [ 38 , 47 , 51 , 53 , 61 , 62 , 63 , 64 , 65 , 66 , 67 ] are cited in the Supplementary Materials. Figure S1.…”

mentioning

confidence: 99%

In Situ Encapsulation of Graphene Quantum Dots in Highly Stable Porphyrin Metal-Organic Frameworks for Efficient Photocatalytic CO2 Reduction

Wang

et al. 2023

Self Cite

Photocatalytic CO2 reduction to valuable hydrocarbon solar fuel is of great significance but still challenging. Strong CO2 enrichment ability and easily adjustable structures make metal-organic frameworks (MOFs) potential photocatalysts for CO2 conversion. Even though pure MOFs have the potential for photoreduction of CO2, the efficiency is still quite low due to rapid photogenerated electron–hole recombination and other drawbacks. In this work, graphene quantum dots (GQDs) were in situ encapsulated into highly stable MOFs via a solvothermal method for this challenging task. The GQDs@PCN-222 with encapsulated GQDs showed similar Powder X-ray Diffraction (PXRD) patterns to PCN-222, indicating the retained structure. The porous structure was also retained with a Brunauer–Emmett–Teller (BET) surface area of 2066 m2/g. After incorporation of GQDs, the shape of GQDs@PCN-222 particles remained, as revealed by the scanning electron microscope (SEM). As most of the GQDs were covered by thick PCN-222, it was hard to observe those GQDs using a transmission electron microscope (TEM) and a high-resolution transmission electron microscope (HRTEM) directly, the treatment of digested GQDs@PCN-222 particles by immersion in a 1 mM aqueous KOH solution can make the incorporated GQDs visible in TEM and HRTEM. The linker, deep purple porphyrins, make MOFs a highly visible light harvester up to 800 nm. The introduction of GQDs inside PCN-222 can effectively promote the spatial separation of the photogenerated electron–hole pairs during the photocatalytic process, which was proved by the transient photocurrent plot and photoluminescence emission spectra. Compared with pure PCN-222, the obtained GQDs@PCN-222 displayed dramatically enhanced CO production derived from CO2 photoreduction with 147.8 μmol/g/h in a 10 h period under visible light irradiation with triethanolamine (TEOA) as a sacrificial agent. This study demonstrated that the combination of GQDs and high light absorption MOFs provides a new platform for photocatalytic CO2 reduction.

“…Photocatalytic hydrogen production from water using solar light as clean and sustainable energy is one of the most promising solutions to solve the energy crisis [1][2][3][4][5]. As a new kind of porous materials, metal-organic frameworks (MOFs) have been applied in many fields such as gas adsorption/storage/separation, sensor, drug delivery, batteries, electrocatalysis, photocatalysis, due to their ultrahigh surface area and void space, adjustable structure, tunable pore sizes, and modifiable internal surfaces [6][7][8][9][10][11][12][13][14][15][16][17][18][19][20][21]. Since Mori et al first reported that MOFs can achieve photocatalytic hydrogen production, a series of MOFs have been reported to show potential in this application [22][23][24][25][26][27][28][29].…”

Section: Introductionmentioning

confidence: 99%

Amino-Functionalized Titanium Based Metal-Organic Framework for Photocatalytic Hydrogen Production

Cai

et al. 2022

Self Cite

Photocatalytic hydrogen production using stable metal-organic frameworks (MOFs), especially the titanium-based MOFs (Ti-MOFs) as photocatalysts is one of the most promising solutions to solve the energy crisis. However, due to the high reactivity and harsh synthetic conditions, only a limited number of Ti-MOFs have been reported so far. Herein, we synthesized a new amino-functionalized Ti-MOFs, named NH2-ZSTU-2 (ZSTU stands for Zhejiang Sci-Tech University), for photocatalytic hydrogen production under visible light irradiation. The NH2-ZSTU-2 was synthesized by a facile solvothermal method, composed of 2,4,6-tri(4-carboxyphenylphenyl)-aniline (NH2-BTB) triangular linker and infinite Ti-oxo chains. The structure and photoelectrochemical properties of NH2-ZSTU-2 were fully studied by powder x-ray diffraction, scanning electron microscope, nitro sorption isotherms, solid-state diffuse reflectance absorption spectra, and Mott–Schottky measurements, etc., which conclude that NH2-ZSTU-2 was favorable for photocatalytic hydrogen production. Benefitting from those structural features, NH2-ZSTU-2 showed steady hydrogen production rate under visible light irradiation with average photocatalytic H2 yields of 431.45 μmol·g−1·h−1 with triethanolamine and Pt as sacrificial agent and cocatalyst, respectively, which is almost 2.5 times higher than that of its counterpart ZSTU-2. The stability and proposed photocatalysis mechanism were also discussed. This work paves the way to design Ti-MOFs for photocatalysis.