Cu-TCPP Nanosheets Research Articles

Attached meso-tetra (4-carboxyphenyl) porphyrin copper (II) to BiOCl for enhanced photocatalytic performance in antibiotics degradation

Bismuth oxychloride (BiOCl) has been considerably accepted as a photocatalyst due to its excellent photoelectrochemical properties, low cost and corrosion resistance. However, its further application has not progressed due to limited visible-light utilization and quick recombination of photoexcited carriers. In this work, a series of meso-tetra (4-carboxyphenyl) porphyrin copper (II) (CuTCPP) hybridized BiOCl composites (CuTCPP/BiOCl) were synthesized to use as an efficient visible-light responsive photocatalyst for the degradation of antibiotics pollutants in the wastewater systems. The characterization results confirmed that the 2D fusiform-shaped CuTCPP nanosheets were successfully inserted into hierarchical flower-like BiOCl. The photocatalytic degradation of several typical antibiotics (tetracycline, enrofloxacin and ciprofloxacin) demonstrated that CuTCPP/BiOCl showed better photocatalytic activities than pure BiOCl. Further, 0.5 wt% CuTCPP/BiOCl manifested the optimal photocatalytic efficiency for decomposing the antibiotics, and its degradation rate constant was about 2.84 times higher than that of pristine BiOCl. The significantly improved photocatalytic performance was mainly due to the promotion of visible light harvesting and enhanced separation of photogenerated carriers after the introduction of the macrocyclic CuTCPP. The radical substances determination confirmed that active •O2−, h+ and •OH existed in the photocatalytic removal of antibiotic, in which •O2− was the main reactive oxidizing species. The excellent degradation efficiency of CuTCPP/BiOCl reveals its great potential as photocatalysts for use in the alleviation of antibiotic contaminants and wastewater purification.

Cross-linking Cu-TCPP@CNT-OH-S as high sulfur loading cathode for Li-S batteries

To obtain high theoretical energy density, lithium–sulfur batteries (LiSBs) with high sulfur loading are urgently required. Herein, sulfur was effectively immobilized on hydroxylated carbon nanotubes (CNT-OH) through chemical reaction deposition strategy to obtain CNT-OH-S, then combining with 2D Cu-TCPP nanosheets (TCPP = tetrakis (4-carboxyphenyl) porphyrin) successfully fabricated a 3D cross-linking Cu-TCPP@CNT-OH-S network, where CNT-OH-S carries the effective polar bond confirmed by FTIR, XPS and SAED tests, and Cu-TCPP promises the inhibition of LiPSs shuttle and promotes kinetics for sulfur conversion explored by UV–vis, symmetrical electrodes tests and XRD in suit. The fast diffusion of Li+ was calculated through CV, and the low electrochemical polarization was demonstrated by GITT, Tafel, GCD, etc., ensuring a high S utilization under practical conditions of high loading. As a consequence, the Cu-TCPP@CNT-OH-S@S cathode with 92.8 wt% sulfur content delivers a high specific capacity of 1448 mAh g−1 at 0.2C, and stabilize at 820 mAh g−1 after 900 cycles. In Li–S pouch cell, a 4.3 mAh cm−2 reversible areal capacity with 10.04 mg cm−2 sulfur loading was obtained at 2C after 100 cycles, which is in the top class among reported porphyrin-based, MOFs-based and nanocarbons-based cathode host.

2D MOF based-heterostructure with hierarchical architecture as antibacterial wound dressing

Bacterial infections pose a huge threat to human health due to the inevitable emergency of drug resistance. Metal-organic frameworks (MOFs) consisting of metal ions and organic linkers, as emerging efficient antibacterial material, have the merits of structural flexibility and adjustable physicochemical property. With assistance of photosensitive agents as organic linkers, MOFs have great potential in antibacterial application through photocatalytic therapy by the generation of reactive oxygen species (ROS). However, the limited light use efficiency and short lifespan of ROS are two obstacles for their applications. Inspired by the semiconductor heterostructure in photocatalysis, we rationally design and precisely synthesize MOFs based heterostructures, in which the TiO2 nanoclusters are filled into the pores of Cu-TCPP nanosheets (i.e. TiO2 NCs@Cu-TCPP HSs). And the composite materials possess three-dimensional (3D) hierarchical architectures, which have advantages of large surface area, excellent light-absorbing ability and photocatalytic efficiency. Significantly, this novel material displays >99.99 % antibacterial efficiency against E. coli and S. aureus within 30 min and preserves the excellent antibacterial ability during reusing three times, which is superior to recently reported photocatalystic-based antibacterial materials. Our study provides new insights into the energy band engineering for enhanced antibacterial performance, paving a way for designing advanced clinical wound dressings.

Ratiometrically electrochemical and colorimetric dual-mode detection of glyphosate based on 2D Cu-TCPP(Fe) NSs

In this work, a dual-signal output sensor was developed for the ratiometrically electrochemical and colorimetric detection of glyphosate (GLYP) based on the duplex nature of 2D Cu-TCPP(Fe) nanosheets (2D Cu-TCPP(Fe) NSs). Cu active center sites in 2D Cu-TCPP(Fe) NSs could transform into CuCl for signal amplification in the presence of chloride ions (Cl−), which dropped dramatically upon GLPY addition due to the strong interaction between GLYP and cuprous ion triggering the competitive reaction with the conversion of CuCl into Cu-GLYP complex. Meanwhile, the constant current signals of Fe2+/3+ in the iron-porphyrin structure of Cu-TCPP(Fe) served as an inner reference, resulting in a ratiometrically electrochemical GLYP sensor. Moreover, 2D Cu-TCPP(Fe) NSs with intrinsic peroxidase-like activity was employed for the colorimetric determination of GLYP based on the specific inhibitory effect of GLYP on the peroxidase activity of 2D Cu-TCPP(Fe) nanozyme. GLYP concentrations can be quantified in the range from 1.0 × 10−10 M to 1.0 × 10−6 M and 1.0 × 10−9 M to 1.0 × 10−7 M, with detection limits of 3.9 × 10−12 M and 1.89 × 10−11 M for ratiometrically electrochemical method and colorimetric assay, respectively. Such a dual-mode sensor with remarkable selectivity, reproducibility, and stability was finally applied for GLYP detection in real samples and reliable outcomes were achieved.

Effect of morphology and structure of CuTCPP nanomaterials on the electrocatalytic CO2 reduction to methane and ethylene

The effect of Cu–N4, Cu–O4 and/or –COOH sites on the electrocatalytic CO2 reduction (ECR) activity and selectivity is rarely evaluated together and directly confirmed through the morphology and structure dependence of ECR performance. Here, the ECR performance of CuTCPP nanoparticles, nanorods, nanosheets and nanoflowers are systematically investigated. The experimental results show that their total ECR activity is nanoflowers > nanosheets > nanoparticles > nanorods. CuTCPP nanosheets with more Cu−N4 sites exposed showed the best ethylene selectivity of 40.6 % at –1.2 V vs. RHE. CuTCPP nanoflowers with more Cu−O4 sites were more stable than the nanosheets, showing 61.0 % methane selectivity at –1.3 V vs. RHE. A series of characterizations reveal that Cu−O4 is mainly responsible for methane production, while Cu–N4 is the main active site for ethylene production and its synergy with Cu–O4 or –COOH groups can improve the ethylene selectivity.

Nanocomposite polymer blend membrane molecularly re-engineered with 2D metal-organic framework nanosheets for efficient membrane CO2 capture

Membrane gas separation technology is an energy-efficient alternative to the traditional industrial processes for CO2 capture towards the mitigation of global warming. To overcome the inherent performance trade-off behavior of polymeric membranes, many nanoarchitectures have been incorporated for developing high-performance mixed matrix membranes. Yet, a successful nanocomposite membrane design remains challenging, especially for CO2 capture, because of polymer-filler incompatibility and interfacial defects. Herein, 2D Cu-TCPP nanosheets were synthesized and incorporated into Pebax/Poly (ethylene glycol) methyl ether acrylate (PEGMEA) blends to design MMMs with exceptional CO2/N2 separation performance. This synergistic polymer blend after crosslinking, offers a highly accommodating and robust matrix environment for the homogenous distribution of nanosheets. Cu-TCPP particles were also produced as 3D nanoflowers to probe their morphological effect on gas transport. The finely dispersed 2D nanosheets expanded the free volume of the resultant nanocomposite membranes, leading to a significantly enhanced CO2 permeability of up to 1183 Barrer which was 93% higher than the neat polymers, while they also increased the transport pathway tortuosity that contributes to a very high CO2/N2 selectivity of 57.6 at a loading of merely 0.1 wt%. Not only do such separation performances surpassed the Robeson upper bound by a large margin and outcompeted many existing advanced MMM designs, but they also remained stable after long-term operations. By carefully elucidating the gas transport tuning effect of 2D metal-organic framework nanosheets in nanocomposite membranes, this work could help broaden their applicability for other environmentally important molecular separations.

In vivo monitoring of glutathione in a live rat brain based on the ratiometric signal output of 2D Cu-TCPP(Fe) nanosheets.

Herein, a novel ratiometric electrochemical platform was developed for in vivo analysis of GSH based on the dual signal output of 2D Cu-TCPP(Fe) nanosheets. Our method with high selectivity and high accuracy enabled GSH monitoring in a live rat brain, and accurate GSH concentrations were firstly reported in different brain regions upon global cerebral ischemia.

Using Cu-TCPP Nanosheets as Interlayers for High-Performance Organic Solvent Nanofiltration Membranes

The development of highly permeable and selective thin-film composite (TFC) membranes is essential for organic solvent nanofiltration (OSN) applications. However, overcoming the permeability–selectivity trade-off in polymer membranes remains highly challenging owing to the difficulty in controlling the thickness and nanostructures of the selective layers. In this study, TFC OSN membranes with sandwich-like structures were developed via interfacial polymerization on Cu-TCPP nanosheet-modified microporous polyvinylidene fluoride (PVDF) substrate surface. The interfacial polymerization was done by using mixed amine (polyethyleneimine and piperazine) in the aqueous phase and the 1,3,5-benzenetricarbonyl trichloride in the hydrophobic ionic liquid phase as monomers. It was found that the Cu-TCPP nanosheets of micrometer lateral dimensions and nanometer thickness (1.5 ± 0.6 nm) can be deposited on the PVDF substrate as an interlayer to facilitate the following interfacial polymerization reaction. The Cu-TCPP interlayer also can be served as a binder between the polyamide selective layer and the microporous PVDF substrate to enhance their mechanical strength. As compared with the PVDF/PA membrane, the PVDF/t-Cu-TCPP/PA membrane exhibited higher elongation (8.0 vs. 4.6%) while ensuring slightly lower tensile strength (36.0 vs. 48.6 MPa). Under optimal synthetic conditions, the TFC membranes could achieve 2.7 L m–2 h–1 bar–1, and 98.9% and 95.0% rejection to Brilliant Blue R (826 Da) and Congo red (697 Da), respectively, in ethanol. Furthermore, the membranes showed steady performance throughout the 36 h nanofiltration of the Rose bengal/ethanol mixture and exhibited good performance in the concentration of lecithin in methanol. Accordingly, this work highlights the potential of using thin metal–organic framework nanosheets as interlayers to develop high-performance TFC membranes for OSN applications.

Strong interfacial interactions of ZnS/Cu-TCPP hybrids contribute to excellent nonlinear optical absorption

In recent years, the research and development of optoelectronic devices based on metal-organic frameworks (MOFs) have increasingly triggered the interest and attention of researchers. However, their nonlinear optical (NLO) properties are in urgent need of improvement. Herein, we first report a method to improve the NLO response of MOFs by decorating ZnS nanoparticles. The NLO response of the hybrid is found to be much higher than that of pure MOFs and ZnS by the Z-scan technique. At higher incident intensities, the hybrids exhibit a giant optical limiting (OL) response with OL threshold as low as 2.82 × 10−7 J/cm2, which is better than almost all organic and inorganic materials reported in the literature so far, demonstrating the great value of hybrids for OL devices. As revealed by XPS characterizations, transient absorption (TA) spectroscopy, and DFT calculations, the strong interfacial interaction between ZnS nanodots and Cu-TCPP nanosheets can effectively promote the charge transfer process between them and significantly inhibit the recombination of photogenerated charge carriers, thus achieving a substantial enhancement of the NLO response. The simple preparation method and extremely low OL threshold suggest that this MOF-based hybrids have great potential for application in OL photonic devices.

A portable paper-based aptasensor for simultaneous visual detection of two mycotoxins in corn flour using dual-color upconversion nanoparticles and Cu-TCPP nanosheets

A portable paper-based microfluidic aptasensor is established to simultaneously and visually detect zearalenone (ZEN) and ochratoxin A (OTA). The targets at the sample zone can migrate to two detection zones through dual-channels and result in green and blue fluorescence recovery. This is due to the specific recognition by a respective aptamer that destroys fluorescence resonance energy transfer (FRET) from dual-color upconversion nanoparticles (UCNPs) to Cu-TCPP nanosheets. By capturing fluorescent images and analyzing the corresponding RGB value via a smartphone, ZEN and OTA can be analyzed with limits of detection down to 0.44 ng/mL and 0.098 ng/mL in the linear ranges of 0.5–100 ng/mL and 0.1–50 ng/mL, respectively. Satisfactory recoveries are also obtained for ZEN (94.5–103.7 %) and OTA (92.2–106.8 %) in corn flour. With the advantages of simple operation, low sample consumption, and broad adaptability, this promising platform allows for the on-site detection of multiple hazards in food.

Cu-TCPP Nanosheets-Sensitized Electrode for Simultaneous Determination of Hydroquinone and Catechol.

It is quite important to develop sensitive, simple, and convenient methods for the simultaneous determination of Hydroquinone (HQ) and Catechol (CC) due to their wide existence, the difficulty of degradation, and the high toxicity. Herein, Cu-TCPP nanosheets were prepared in N,N-dimethylformamide (DMF) through the solvent exfoliation method. The morphology and electrochemical performance of Cu-TCPP were characterized, revealing its stacked sheet structure with abundant pores, a fast electron transfer ability, and a large electrode active area. Using Cu-TCPP nanosheets as the sensitive material to modify the glassy carbon electrodes (Cu-TCPP/GCEs), it was found that they had an obvious enhancement effect on the electrochemical oxidation currents of HQ and CC. The signal enhancement mechanism was explored. The Cu-TCPP nanosheets not only enhanced the accumulation abilities of HQ and CC, but also improved their apparent catalytic rate, displaying high sensitivity for HQ and CC. The values of the detection limit were calculated to be 3.4 and 2.3 nM for HQ and CC. A satisfactory recovery was obtained when this method was used in measuring HQ and CC in the water samples.

Solvent-exfoliated Cu-TCPP nanosheets: Electrochemistry and sensing application in simultaneous determination of 4-aminophenol and acetaminophen

The design and preparation of 2D metal-organic frameworks (MOFs) can effectively improve the performance of electrochemical sensing. In this work, a series of Cu-TCPP nanosheets (TCPP: Tetrakis(4-carboxyphenyl)porphyrin) are prepared through ultrasonic exfoliation of bulk Cu-TCPP in different solvents, including ethanol absolute (EtOH), N,N-dimethylformamide (DMF), N-methyl-2-pyrrolidone (NMP), and ultrapure water (H2O). The exfoliation ability of DMF is higher than EtOH, H2O, and NMP, and the exfoliated Cu-TCPP nanosheets in DMF (Cu-TCPP-DMF) are more uniform and thinner due to their approximate surface energy. Then, the electrochemistry of different Cu-TCPP nanosheets is studied. Cu-TCPP-DMF modified glassy carbon electrode (Cu-TCPP-DMF/GCE) features higher redox activity, larger electrochemical response area, faster electron transfer ability, and higher enhancement effects toward the oxidation of 4-aminophenol (4-AP) and acetaminophen (AC). The corresponding electrochemical reaction mechanisms are explored. Using Cu-TCPP-DMF as sensing material, a platform for simultaneous measurement of 4-AP and AC is successfully developed with the determination limit of 2.6 and 1.9 nM. The wonderful recoveries are also obtained when the sensor is used to determine 4-AP and AC in urine, river water and commercial paracetamol tablet. This work is in favor of constructing a novel 2D MOFs based electrochemical sensing system with superior performance.

Fabrication of organic solvent nanofiltration membrane using commercial PVDF substrate via interfacial polymerization on top of metal-organic frameworks interlayer

Interfacial polymerization (IP) is a rapid and convenient approach to fabricating thin-film composite (TFC) membranes with high permeance and satisfactory rejection for organic solvent nanofiltration (OSN). However, it is normally difficult to directly conduct the IP approach on the commercial membrane substrate (particularly, in the microfiltration range) because the monomers on the substrate are unevenly distributed during the IP reaction. In the current work, Cu-TCPP nanosheets were in-situ grown on commercial PVDF microfiltration substrate (pore size of 0.45 μm) by using preinstalled Cu2O nanoparticles as a copper ion source. The Cu-TCPP nanosheets covered the large pores and penetrated the surface layer of the PVDF substrate. The obtained PVDF/i-Cu-TCPP was then used as a substrate to conduct the IP and to fabricate the PVDF/i-Cu-TCPP/PA membrane. It was found that i-Cu-TCPP which serves as an interlayer could store the aqueous solution of the amine and was critical to the formation of a thin and defect-free polyamide separation layer. In comparison, loading of the Cu-TCPP on the PVDF substrate by filtration led to the formation of PVDF/e-Cu-TCPP/PA, which however exhibited inferior separation performance as compared to the PVDF/i-Cu-TCPP/PA membrane. More importantly, the PVDF/i-Cu-TCPP/PA membrane exhibited higher tensile strength (6.0 vs. 2.8 MPa) compared to the PVDF/e-Cu-TCPP/PA membrane, due to the enhanced interaction (adhesion) between the PVDF substrate and the i-Cu-TCPP interlayer. Under optimal synthetic conditions, the permeance of the PVDF/i-Cu-TCPP/PA membrane was almost 4 times that of the PVDF/PA membrane (1.93 vs. 0.49 L m-2 h-1 bar-1) without compromising rejection (>96%). The optimal TFC membrane also showed excellent OSN performance towards various organic solvents and good long-term stability to VB12/ethanol mixtures (50 h). Furthermore, the concentration test of erythromycin in methanol solution indicated that the PVDF/i-Cu-TCPP/PA membrane has great potential in the pharmaceutical industry for drug concentration and organic solvent recovery.

Biocompatible 2D Cu-TCPP Nanosheets Derived from Cu2O Nanocubes as Multifunctional Nanoplatforms for Combined Anticancer Therapy.

Two-dimensional (2D) metal-organic frameworks (MOFs) could serve as multifunctional nanoplatforms to load small-molecule drugs and enzyme-mimicking nanoparticles (NPs) with a high efficiency for combined cancer therapy. Herein, we have prepared novel 2D Cu-tetrakis (4-carboxyphenyl) porphyrin (TCPP) nanosheets with an average thickness of 1.2 ± 0.1 nm using Cu2O nanocubes (50 nm) as a template and solid copper ion supplier. Cu2O nanocubes can be consumed and hybridized with the obtained Cu-TCPP, depending on the molar ratio of Cu2O and TCPP linker. The resultant Cu2O/Cu-TCPP could serve as nanoplatforms for co-loading of Pt and Au NPs to construct multifunctional Cu2O/Cu-TCPP/(Pt-Au) nanomedicines, which showed a superior anticancer effect via multiple therapeutic modes. For instance, Cu(II)-TCPP can produce 1O2 in the presence of acidic H2O2 by the Russell mechanism and the intrinsic Cu(I) ions (derived from the residual Cu2O) could mediate a Fenton-like reaction in tumorous tissues to generate toxic hydroxyl radicals (•OH). Moreover, the loaded Pt NPs with catalase (CAT)-mimic activity could decompose hydrogen peroxide (H2O2) into O2 within the tumor cells, increasing the local O2 concentration, modulating the tumorous hypoxia atmosphere, and promoting the O2-dependent glucose oxidation reaction. Furthermore, Au NPs with glucose oxidase (GOx)-mimic activity could accelerate the consumption of glucose and cut nutrient supply to induce starvation therapy. Consequently, our designed 2D MOF-based therapeutic nanomedicines would be a promising candidate for future smart and combined cancer therapy.

Integration of P84 and porphyrin–based 2D MOFs (M−TCPP, M = Zn, Cu, Co, Ni) for mixed matrix membranes towards enhanced performance in organic solvent nanofiltration

• Four porphyrin-based MOFs were synthesized as nanofillers for membrane fabrication. • 2D porphyrin–based MOFs have high compatibility with the P84 polymeric matrix. • The optimal MMMs exhibited 3-folds enhancement in permeance without rejection loss. • Ultrasonic treatment of Cu-TCPP further increased dispersion and OSN performance. • Stable OSN performance (36 h) was observed for separating VB12/ethanol solutions. Mixed matrix membranes (MMMs) are promising candidates for organic solvent nanofiltration (OSN), but the thick separation layer and poor compatibility between polymer and fillers are two critical challenges needed to be solved. Herein, a series of tetrakis(4-carboxyphenyl)porphyrin (abbreviation: TCPP) based metal–organic frameworks (MOFs, M−TCPP (M=Zn, Cu, Co, Ni)) have been synthesized in the form of two–dimensional nanosheets, which were then used as thin fillers in P84 matrix to fabricate M−TCPP/P84 MMMs for the OSN application. The effects of the types of M−TCPP and loading contents in the resultant MMMs on the OSN performance were systematically investigated. All the obtained MMMs exhibited higher permeance and slightly declined rejection of brilliant blue R (BBR) as compared with the pristine P84 membranes, among which Zn-TCPP/P84 MMM showed the greatest permeance improvement due to its flower-like structure assembled by wrinkled nanosheets as building blocks. Moreover, the permeance of MMMs showed volcanic type curves as increasing the MOFs loading content, while the rejection did not sacrifice too much. The optimum loading contents for Cu-TCPP/P84 and Zn-TCPP/P84 MMMs were 1 wt% and 1.5 wt%, respectively. In addition, the water-stable Cu-TCPP MOF can be further disassembled by an ultrasonic probe to achieve monodispersed Cu-TCPP nanosheets. It is interesting to find that the permeance of the MMM incorporating 1.5 wt% of the monodispersed Cu-TCPP nanosheets was enhanced nearly 2-fold as compared with the MMM with the untreated Cu-TCPP MOFs and the rejection to BBR only slightly decreased (94.7 vs. 95.7%). Besides, the general applications of Cu-TCPP/P84 membranes for other organic solvents (methanol, isopropanol, acetone, acetonitrile, hexane, etc. ), diverse organic dye/ethanol separation, vitamins B12/ethanol long-term separation test (36 h) indicated that the M−TCPP−based MMMs have great potentials in the field of organic solvent-related separation.

A novel CRISPR/Cas14a system integrated with 2D porphyrin metal-organic framework for microcystin-LR determination through a homogeneous competitive reaction

Selective and sensitive detection of microcystin-LR (MC-LR) is of vital importance because of its high toxicity and broad distribution. Herein, a novel and versatile fluorescence sensor (Cas14-pMOFs fluorescence sensor) was developed by combining the CRISPR/Cas14a system with a 2D porphyrin metal-organic framework nanosheets (2D-pMOFs) for MC-LR determination. The designed CRISPR/Cas14a system was activated by the unbound complementary DNA (cDNA), which was positively correlated with MC-LR concentration. Furthermore, the activated Cas14a protein was utilized to indiscriminately cleave the FAM-labeled single-stranded DNA (ssDNA-FAM), which was pre-absorbed on Cu-TCPP(Fe) nanosheets. Because of the desorption of the cleaved ssDNA-FAM, the pre-quenched fluorescence signal was recovered. Owing to the excellent performance in quantifying cDNA using this Cas14-pMOFs fluorescence sensor with a limit of detection (LOD) of 0.12 nM, this Cas14-pMOFs fluorescence sensor was able to detect MC-LR in a range from 50 pg/mL to 1 μg/mL with the LOD of 19 pg/mL. This work not only provided a new insight for the exploration of fluorescence sensors based on 2D-pMOFs coupled with CRISPR/Cas14a, but also, demonstrated its universality in both nucleic acid and non-nucleic acid targets determination.

Porphyrin-assisted synthesis of hierarchical flower-like polypyrrole arrays based flexible electrode with high areal capacitance

Flexible free-standing electrode with special hierarchical structure have received widespread attentions due to the increased specific surface area, shortened transport path of electrolyte ions and accelerated ion transmission. Herein, for the first time, the flexible free-standing three-dimensional (3D) flower-like polypyrrole/5,10,15,20-tetrakis(4-carboxylphenyl)porphyrin copper (II) (TF-PPy/Cu-TCPP) nanocomposite electrode with hierarchical PPy micro-flower arrays on the surface has been fabricated via the combination of electrophoretic deposition and electrochemical polymerization. The growth mechanism is involved in the following aspects. I) The wrinkled Cu-TCPP nanosheets provide abundant porous channels to facilitate the immersion of pyrrole molecules and uniform cross-linking of PPy. II) The rough surface of the PPy/Cu-TCPP composite film provides rough sites for the growth of hierarchical TF-PPy arrays under the assistance of H2 bubbles. The collaborative advantages of 3D conductive networks and the hierarchical TF-PPy arrayed on the rough surface of electrode facilitate the fast ion/electron transport for the enhanced electrochemical performances. The corresponding TF-PPy/Cu-TCPP electrode shows an areal capacitance of 593 mF cm−2 at 0.5 mA cm−2, which is superior to the PPy/Cu-TCPP electrode (351 mF cm−2) and the pristine PPy (287 mF cm−2). The symmetric supercapacitor exhibits the energy density of 5.94 μW h cm−2 at a highest power density of 25 μW cm−2. This work will further enrich the valuable design concepts of flexible free-standing electrode with hierarchical structure for energy storage and conversion.

Graphene-like MOF nanosheets stabilize graphene oxide membranes enabling selective molecular sieving

Thin laminar membranes assembled by 2D nanomaterials evince the potential to achieve rapid and efficient molecular transport due to precisely amendable in-plane pores and interlayer distances. Despite the extensive use of graphene oxide (GO) membranes for water treatment, water-induced instability and the barrier effect remain challenging issues to be addressed. Here, a water-stable, graphene-like MOF nanosheet (Cu-TCPP) was implemented as a framework bridge to stabilize the GO laminates against swelling and redispersion into water. A stable heterostructure was established by the electrostatic interaction between porphyrin and oxygen-containing groups, and metal coordination of the carboxyl groups of GO nanosheets. The presence of ultrathin Cu-TCPP nanosheets promotes the formation of a nano-wrinkled surface with vertical-slit and in-plane pores that dominate the significantly improved water transport. The resultant composite membranes evince a 7-fold-higher water permeance (165.2 L m−2 h−1 bar−1) than that of GO membranes with remarkable solute retention (Congo red: 99.1%). Furthermore, this membrane shows an excellent sieving ability either for RB5/MO solutions or for CR/salt mixtures, while achieving a remarkable antibacterial activity against E. coli. The combination of rigid and flexible nanosheets opens an avenue to construct a water-stable multi-channel frame for the next generation of porous 2D materials for water purification.

Fabrication an electrochemical sensor based on composite of Cu-TCPP nanosheets and PSS functionalized graphene for simultaneous and sensitive determination of dihydroxybenzene isomers

Abstract A novel electrochemical sensor based on the combination of two-dimensional metal–organic framework Cu-porphyrin (Cu-TCPP) and poly(styrene sulfonate) functionalized graphene (PSS-Gr) denoated as PSS-Gr@Cu-TCPP was constructed and applied to simultaneously determine dihydroxybenzene isomers. The nanocomposite was synthesized by a simple ultrasonic mixing method and characterized by transmission electron microscopy (TEM), UV–Vis absorption and electrochemical techniques. The electrochemical behaviors of dihydroxybenzene isomers including hydroquinone (HQ), catechol (CT) and resorcinol (RS) on PSS-Gr@Cu-TCPP modified electrode were investigated and their oxidation peak potentials were separated evidently with the oxidation peak currents enhanced significantly on the modified electrode, which were attributed to the remarkable electrocatalytic activity of the nanocomposite on the oxidation of three isomers. Under the optimized conditions, the proposed sensor showed a wide linear concentration range of 1–200 μM, 0.08–120 μM and 5–100 μM with the low detection limit of 1 μM, 0.08 μM, 5 μM for hydroquinone, catechol and resorcinol. In addition, the fabricated electrochemical sensor was successfully applied to detect three dihydroxybenzene isomers in real samples with satisfactory recovery. This work provided a simple and sensitive approach for simultaneous determination of dihydroxybenzene isomers.

Cu-TCPP nanosheets blended polysulfone ultrafiltration membranes with enhanced antifouling and photo-tunable porosity

The major obstacle in membrane filtration technology is the membrane fouling, which not only decreases the membrane efficiency, but also enhances its operational cost. In order to fabricate a membrane with antifouling characteristics, potential nanofillers have been added to the engineering polymer(s) to make a composite to improve the membrane efficiency. Herein, we incorporate porphyrin-based ultrathin, highly ordered porous photothermal responsive copper tetrakis(4-carboxyphenyl)porphyrin (Cu-TCPP) nanosheets as a novel nanofillers into the polysulfone (PSf) matrix. High loading (6 wt%) and well dispersed Cu-TCPP nanosheets incorporated polysulfone nanocomposite (Cu-TCPP/PSf) ultrafiltration membranes are prepared via non-solvent induced phase inversion. The Cu-TCPP/PSf composite membranes demonstrate pronounced antifouling and antibiofouling potential along good separation performance. The nanocomposite membranes demonstrate photo-induced pore tuning due to the local heating of photothermal Cu-TCPP nanosheets by visible light, which further improves the membrane separation efficiency. The Cu-TCPP/PSf composite membrane with 6 wt% Cu-TCPP nanosheets enhances the pure water permeance from 23.42 to 260.61 L·m−2·h−1·bar−1, with improved antifouling potential, precise permeance recovery ratio of 99.13% after three cycles, and good separation performance for 100 and 200 nm particles. Considering relatively moderate cost, facile processing, tunable porosity, durable and good mechanical strength along restrained swelling, the Cu-TCPP/PSf membranes are considered as potential candidate as antifouling/antibiofouling ultrafiltration membranes for water purification.