The sandwich-structured MnTMPyP/NbWO6 nanocomposites were synthesized by the electrostatic self-assembly of the manganese porphyrin (MnTMPyP) cations with the exfoliated niobium tungstate [NbWO6]− nanosheets. Various analytical techniques such as X-ray diffraction patterns, scanning electron micrograph, transmission electron microscope, energy-dispersive spectroscopy, UV–Vis absorption spectra and Fourier transform infrared spectra were used to determine the structure, composition and morphology of the as-prepared samples. It can be concluded that MnTMPyP cations were inserted into interlayer spacing of the [NbWO6]− nanosheets and arranged in an inclined single layer at 58°. The MnTMPyP/NbWO6 nanocomposites modified electrode exhibited excellent electro-catalytic oxidation activity toward nitrite in 0.2 mol L−1 and pH 7.0 phosphate buffer solution. Additionally, the oxidation peak current is proportional to the square root of scan rates, indicating that the redox reaction of nitrite is a typical diffusion-controlled process. Also, the sensitivity and detection limit for nitrite at the modified electrode was evaluated as 3.80 × 10−5 mol L−1 over a concentration range from 1.20 × 10−4 to 3.57 × 10−3 mol L−1 by using differential pulse voltammetry.

Preparation of manganese porphyrin/niobium tungstate nanocomposites for enhanced electrochemical detection of nitrite

Synthesis of Schiff base-based cationic Gemini surfactants and evaluation of their effect on in-situ AgNPs preparation: Structure, catalytic, and biological activity study

Impact of hydrophobic tails of new phospho-zwitterionic surfactants on the structure, catalytic, and biological activities of AgNPs

A novel layered nanocomposite CoTMPyP/Ti5NbO14 was synthesized via exfoliation/restacking where cobalt porphyrin (CoTMPyP) was intercalated into exfoliated titanoniobate (Ti5NbO14) nanosheets. The ...

Synthesis of cobalt porphyrin/Ti5NbO14 nanocomposite used as an ascorbic acid electrochemical detection material

2D perovskite Sr2Nb3O10 (SNO) nanosheets were synthesized by cation exchange-assisted liquid exfoliation and applied as supports for the immobilization of palladium (Pd) nanoparticles through the electrostatic assembly with Pd(NH3)42+ precursors and successive in-situ photoreduction. Pd nanoparticles with an average diameter of 9.22 nm are uniformly dispersed on the surface of strontium niobate nanosheets. The obtained nanohybrid Pd-SNO could serve as an efficient heterogeneous catalyst for the atmospheric pressure oxidation of benzyl alcohol to benzaldehyde by using air as an oxidizing agent and water as the sole solvent at low temperature (80 °C). Furthermore, the catalyst could be easily separated from the reaction mixture by simple centrifugation and reused five times without significant degradation in catalytic activity under the investigated conditions. We believe that the synthetic strategy described in this work is a feasible means of developing effective noble metal/layered transition metal oxide hybrid catalysts for organic reactions.

Highly dispersive Pd nanoparticles decorated strontium niobate nanosheets: Efficient and recyclable catalyst for base-free aerobic oxidation of benzyl alcohols in water

Ag nanoparticles were successfully deposited onto calcium niobate nanosheets using the electrostatic self-assembly method, followed by UV irradiation photoreduction. Various characterization techniques including XRD, SEM, HRTEM, BET and XPS have been utilized to study the material crystalline structure, microstructure, pore size and surface properties. Silver nanoparticles in the size range of 2–8 nm are well dispersed on the surface of the calcium niobate nanosheets. The as-synthesized Ag-Ca2Nb3O10 was a mesoporous material with a broad pore size distribution. Ag-Ca2Nb3O10 exhibited remarkable catalytic activity for the reduction of 4-nitrophenol (4-NP) by NaBH4 solution under ambient conditions, and no obvious activity degradation was observed after 5 cycles of durability test. The reduction has a pseudo-first-order rate constant of 18.01 × 10−3 s − 1 and an activity parameter of 6.00 s − 1 g − 1. The activation energy (Ea) of the reduction reaction was calculated as 59.63 kJ mol−1. The catalyst was recycled several times without any significant catalytic activity loss. This work provides a facile route to synthesize a highly efficient catalyst for the reduction of organic pollutants.

Immobilization of well-dispersed Ag nanoparticles on calcium niobate nanosheets as highly active catalyst towards reduction of 4-nitrophenol

As functional molecules, the cationic manganese (III) tetrakis-5, 10, 15, 20-(N-methyl-4-pyridyl) porphyrins (MnTMPyP) were used to assemble with the exfoliated Ca2Nb3O10− nanosheets, which were ob...

A biosensor consisting of Ca2Nb3O10− substrates and functional molecule manganese porphyrins (MnTMPyP) utilized for the determinations of nitrite

Intercalated cobalt porphyrin between layered double hydroxide nanosheets as an efficient and recyclable catalyst for aerobic epoxidation of alkenes

A novel ionic liquid/α-ZrP (C16MIM/α-ZrP) lamellar nanocomposite was fabricated via the electrostatic self-assembly deposition technique by using exfoliated α-ZrP nanosheets and guest molecules (1-hexadecyl-3-methylimidazolium bromide) as building blocks under mild conditions. C16MIM/α-ZrP nanocomposite was characterized by various analytical techniques such as X-ray diffraction (XRD), transmission electron microscopy (TEM), scanning electron microscope (SEM), Fourier transform infrared spectroscopy, and synchronous thermal analyzer. The net interlayer spacing of α-ZrP determined by XRD confirmed that the C16MIM cations formed a monolayer arrangement between the α-ZrP nanosheets. The morphology and microstructure of C16MIM/α-ZrP composite were observed using SEM and TEM. The C16MIM/α-ZrP modified glass carbon electrode exhibited excellent electrocatalytic activity toward the oxidation of nitrite in weak base media. The results obtained with differential pulse voltammetry demonstrated that the C16MIM/α-ZrP hybrid detected nitrite linearly in the concentration range from 7.3 μM to 1.25 mM with the detection limit of 1.26 μM (S/N = 3). Additionally, the prepared sensor showed outstanding reproducibility, high stability, and anti-interference capability.

https://www.cambridge.org/core/services/aop-cambridge-core/content/view/D28A776E5E503238771562ED765F9F9B/S0884291420002253a.pdf/div-class-title-nitrite-sensor-based-on-room-temperature-ionic-liquid-functionalized-zirconium-phosphate-modified-glassy-carbon-electrode-div.pdf

Nitrite sensor based on room temperature ionic liquid functionalized α-zirconium phosphate modified glassy carbon electrode

Co 5,10,15,20-tetrakis(4-sulfonatophenyl) porphyrin (CoTPPS) anions were successfully immobilized into the lamellar space of Mg–Al LDH through the spontaneous flocculation method by using exfoliated LDH nanosheets and guest molecules as building blocks. A variety of techniques including XRD, IR, UV–Vis, SEM, TEM and TG–DSC have been applied to characterize the morphology and microstructure of the obtained hybrids. It was found that the ratio between the metalloporphyrin molecules and LDH nanosheets has an important effect on the structure of restacking products. The interlayer spacing determined from XRD result suggests that a perpendicular orientation of the CoTPPS anions in the lamellar space. The surface charge changes associated with the flocculation process were traced through zeta potential measurements. The immobilized CoTPPS could act as an efficient and reusable heterogeneous catalyst for selective epoxidation of various alkenes including different cycloalkenes, styrene derivatives and long-chain alkenes. Cyclohexene undergoes up to 99% conversion within 2 h and 90% selectivity with molecular oxygen as environmentally friendly oxidant and isobutyraldehyde as co-reductant at room temperature. The CoTPPS/LDH2.0 can be easily recovered and reused for at least 5 times without obvious decrease of activity. This work provides a facile route to synthesize a highly efficient catalyst for the green epoxidation of olefins.

The direct assembly of metalloporphyrin and Mg–Al layered double hydroxides nanosheets: a highly efficient catalyst for the green epoxidation of olefins

Bin Zhang

Papers

Immobilization of well-dispersed Ag nanoparticles on calcium niobate nanosheets as highly active catalyst towards reduction of 4-nitrophenol

A biosensor consisting of Ca2Nb3O10− substrates and functional molecule manganese porphyrins (MnTMPyP) utilized for the determinations of nitrite

Intercalated cobalt porphyrin between layered double hydroxide nanosheets as an efficient and recyclable catalyst for aerobic epoxidation of alkenes

Nitrite sensor based on room temperature ionic liquid functionalized α-zirconium phosphate modified glassy carbon electrode

The direct assembly of metalloporphyrin and Mg–Al layered double hydroxides nanosheets: a highly efficient catalyst for the green epoxidation of olefins