Interfacial coupling effect promotes selective electrocatalytic oxidation of 5-hydroxymethylfurfural into the value-added products under neutral conditions

Owing to the sluggish reaction kinetics, it is a promising yet challenging task to achieve the adequate electricity-driven catalytic oxidation of biomass-derived 5-hydroxymethylfurfural (HMF) in neutral conditions. Herein, we have prepared an elelctrocatalyst with interfacial coupling effect through in-situ growth of Cu phthalocyanine (CuPc) on Co3O4 spinel (Co3O4/CuPc), which constructs an effective electrocatalytic system of HMF oxidation with overall oxidation value-added products yield and total Faraday efficiency up to 80% and 70%, respectively. The interfacial coupling effect between CuPc and Co3O4 spinel improve catalytic activity by effectively boosting the interfacial charge transfer and reducing the formation energy of key *C6H3O4 in the catalytic pathway according to the in situ Raman spectroscopy and DFT simulation. This work illustrates the significance of interfacial coupling effect for developing highly efficient electrocatalysts applied for neutral system of biomass oxidation.

Floating metal phthalocyanine@polyacrylonitrile nanofibers for peroxymonosulfate activation: Synergistic photothermal effects and highly efficient flowing wastewater treatment

Highly efficient floating photocatalysis has potential applications in organic pollutant treatment but remains limited by low degradation efficiency in practical applications. By introducing the photothermal effect into a peroxymonosulfate (PMS) coupled photocatalysis system, tetracycline hydrochloride (TCH) degradation could be significantly enhanced using floating metal phthalocyanine@polyacrylonitrile (MPc@PAN) nanofiber mats. MPc@PAN nanofibers with different metal centers showed similar photothermal conversion performance but different activation energies for PMS activation, resulting in metal-center-dependent synergistic photothermal effects, i.e., light-enhanced dominated, thermal-enhanced dominated, and conjointly light-thermal dominated mechanisms. The porous structures and floating ability of the FePc@PAN nanofibers provided a fast mass transfer process, with higher solar energy utilization and superior photothermal conversion performance than the FePc nanopowders. Meanwhile, the FePc@PAN nanofibers showed excellent TCH removal stability within 10 cycles (>92%) and extremely low Fe ion leaching (<0.055 mg/L) in a dual-channel flowing wastewater treatment system. This work provides new insight into PMS activation via photothermal effects for environmental remediation.

Mechanical and Thermal Characterization of Annealed Oriented PAN Nanofibers

Polyacrylonitrile (PAN) nanofibers have extensive applications as filters in various fields, including air and water filtration, biofluid purification, and the removal of toxic compounds and hazardous pollutants from contaminated water. This research focuses on investigating the impacts of annealing on the mechanical and thermal characteristics of oriented PAN nanofibers produced through the electrospinning of a PAN solution. The nanofiber mats were subjected to annealing temperatures ranging from 70 °C to 350 °C and characterized using a tensile test machine, thermogravimetry, differential scanning calorimetry, and scanning electron microscopy (SEM). The study aimed to examine the tensile strength in the transverse and longitudinal directions, Young's modulus, and glass transition temperatures of PAN nanofiber mats. The results indicate that, upon annealing, the diameter of the nanofibers decreased by approximately 20%, while the tensile strength increased in the longitudinal and transverse directions by 32% and 23%, respectively. Furthermore, the annealing temperature influenced the glass transition temperature of the nanofiber mats, which exhibited a 6% decrease at 280 °C, while the degradation temperature showed a slight increase of 3.5% at 280 °C. The findings contribute to a better understanding of the effects of annealing on PAN nanofiber mats, facilitating their potential for various filtration applications.

In situ growth of copper(ii) phthalocyanine-sensitized electrospun CeO2/Bi2MoO6 nanofibers: a highly efficient photoelectrocatalyst towards degradation of tetracycline

Copper(ii) phthalocyanine-sensitized electrospun CeO₂/Bi₂MoO₆ nanofibers (TNCuPc/CeO₂/Bi₂MoO₆ nanofibers) were fabricated and applied as an efficient novel photocatalyst with enhanced photoelectrocatalytic activity.

Preparation and application of α-Fe2O3@MIL-101(Cr)@TiO2 based on metal–organic framework for photocatalytic degradation of paraquat

In this study, a new magnetic α-Fe2O3@MIL-101(Cr)@TiO2 photocatalyst was successfully synthesized. The material synthesized had been fully characterized by Fourier transform infrared spectroscopy, scanning electron microscopy, energy-dispersive X-ray spectroscopy, vibrating sample magnetometry, transmission electron microscopy, and Brunauer–Emmett–Teller isotherm methods. The X-ray diffraction analysis corroborates that nanoparticles are polycrystalline with rhombohedral and tetragonal crystal structures for Fe2O3 and TiO2, respectively. In addition, the photocatalytic degradation of the herbicide paraquat in the presence of α-Fe2O3@MIL-101(Cr)@TiO2 under ultraviolet (UV) irradiation was studied. The effect of experimental parameters such as the initial concentration of catalyst, the pH, and the initial paraquat was investigated. The optimal conditions were achieved for concentration of catalyst 0.2 g L−1, pH 7, and concentration of paraquat 20 mg L−1. The photocatalytic degradation efficiency was 88.39% after 15 min with α-Fe2O3@MIL-101(Cr)@TiO2 under UV irradiation. The pseudo-second-order kinetic model for photocatalytic degradation of paraquat was obtained. The catalysts could be recovered and reused without any loss of efficiency for five times in the consequent reactions. To the best of our knowledge, this is the first report on the photocatalytic degradation of paraquat using new α-Fe2O3@MIL-101(Cr)@TiO2 photocatalyst under UV irradiation condition.

Construction of a three-dimensional nest-like lithium ferrite/reduced graphene oxide composite with enhanced visible-light photocatalytic activity

Magnetic separable nest-like LiFe₅O₈/RGO was synthesized and displayed superior photocatalytic activity under visible-light irradiation because of its unique nest-like structure.

Efficient photocatalytic degradation of acid fuchsin in aqueous solution using separate porous tetragonal-CuFe2O4 nanotubes

To develop a new promising magnetic photocatalyst, homogeneous tetragonal-CuFe2O4 (t-CuFe2O4) nanotubes were successfully synthesized via the electrospinning technique followed by heating treatment. The detailed investigation of chemical phase and microstructure reveals that the obtained samples are inversely spinel CuFe2O4 nanotubes with an average diameter of about 272±2nm, which are assembled by numerous CuFe2O4 single crystal nanoparticles with regular polyhedron structure and possess a very outstanding porous feature. Furthermore, element mapping, UV-vis adsorption spectrum, N2 adsorption-desorption isotherm, and magnetic hysteresis loop indicate that these t-CuFe2O4 nanotubes have uniform component distribution, strong light response in the range of 200 nm-800 nm, considerable specific surface area of 12.8 m(2)/g and porosity of 15.5 nm, and enough magnetization of about 18 emu/g. Therefore, the t-CuFe2O4 nanotubes show an excellent catalytic activity and durability for the photodecomposition of acid fuchsin dye in aqueous solution under a simulated sunlight source. Furthermore, these CuFe2O4 nanotubes could be acted as an eco-friendly and recyclable photocatalyst because they can be efficiently separated from the residual solution. Finally, a mechanism is presented for the significant photocatalytic performance of the porous CuFe2O4 nanotubes.

Novel flexible belt-shaped coaxial microcables with tunable multicolor luminescence, electrical conductivity and magnetism

Novel flexible belt-shaped coaxial microcables [Fe₃O₄/PANI/PMMA]@{[Eu(BA)₃phen + Tb(BA)₃phen]/PMMA} with tunable multicolor luminescence, electrical conductivity and magnetism have been successfully fabricated by one-pot electrospinning.

Photo-induced reduction of CO2using a magnetically separable Ru-CoPc@TiO2@SiO2@Fe3O4catalyst under visible light irradiation

An efficient photo-induced reduction of CO₂using magnetically separable Ru-CoPc@TiO₂@SiO₂@Fe₃O₄as a heterogeneous catalyst in which CoPc and Ru(bpy)₂phene complexes were attached to a solid supportviacovalent attachment under visible light is described.

Cobalt phthalocyanine immobilized on graphene oxide: an efficient visible-active catalyst for the photoreduction of carbon dioxide

New graphene oxide (GO)-tethered-Co(II) phthalocyanine complex [CoPc-GO] was synthesized by a stepwise procedure and demonstrated to be an efficient, cost-effective and recyclable photocatalyst for the reduction of carbon dioxide to produce methanol as the main product. The developed GO-immobilized CoPc was characterized by X-ray diffraction (XRD), FTIR, XPS, Raman, diffusion reflection UV/Vis spectroscopy, inductively coupled plasma atomic emission spectroscopy (ICP-AES), thermogravimetric analysis (TGA), Brunauer-Emmett-Teller (BET), scanning electron microscopy (SEM), and transmission electron microscopy (TEM). FTIR, XPS, Raman, UV/Vis and ICP-AES along with elemental analysis data showed that Co(II) -Pc complex was successfully grafted on GO. The prepared catalyst was used for the photocatalytic reduction of carbon dioxide by using water as a solvent and triethylamine as the sacrificial donor. Methanol was obtained as the major reaction product along with the formation of minor amount of CO (0.82 %). It was found that GO-grafted CoPc exhibited higher photocatalytic activity than homogeneous CoPc, as well as GO, and showed good recoverability without significant leaching during the reaction. Quantitative determination of methanol was done by GC flame-ionization detector (FID), and verification of product was done by NMR spectroscopy. The yield of methanol after 48 h of reaction by using GO-CoPc catalyst in the presence of sacrificial donor triethylamine was found to be 3781.8881 μmol g(-1)  cat., and the conversion rate was found to be 78.7893 μmol g(-1) cat. h(-1). After the photoreduction experiment, the catalyst was easily recovered by filtration and reused for the subsequent recycling experiment without significant change in the catalytic efficiency.

Synthesis, characterization and photocatalytic activity of magnetically separable hexagonal Ni/ZnO nanostructure

The hexagonal zinc oxide coated nickel (Ni/ZnO) nanostructure photocatalyst has successfully been prepared by the reduction of nickel chloride hexahydrate using hydrazine hydrate through the solvothermal process at 140 °C followed by surface modification of the product by the reflux method at 110 °C for 1 h. The X-ray diffraction (XRD) pattern showed that the 'as prepared' sample consists of face centered cubic Ni and hexagonal wurtzite ZnO without any traces of impurity. Field emission scanning electron microscopy (FESEM) and transmission electron microscopy (TEM) images confirmed the formation of nickel nanoparticles under solvothermal conditions. These nickel nanoparticles, when subjected to reflux, formed the hexagonal zinc oxide coated nickel nanostructure. Fourier transform infrared (FTIR) spectra, photoluminescence (PL) and Raman studies also confirmed the presence of zinc oxide in the hybrid nanostructure. The growth mechanism for the development of the hexagonal zinc oxide coated nickel (Ni/ZnO) nanostructure has also been proposed. The appearance of the hysteresis loop, in the as-prepared Ni/ZnO hybrid nanostructure, demonstrated its ferromagnetic character at room temperature. The hexagonal Ni/ZnO nanostructure also acts as an efficient photocatalyst in the degradation of methylene blue under ultraviolet light irradiation. It is observed that the catalytic efficiency of the hybrid nanocatalyst is better compared to pure zinc oxide. Most importantly, the Ni/ZnO catalyst could also be easily separated, simply by applying an external magnetic field, and reused.

Nanostructured metallophthalocyanine complexes: synthesis and electrocatalysis

In this review, we have attempted to summarize the synthesis and catalytic applications of the nanophthalocyanine complexes. In cases where possible, we have compared the catalytic activity of the nanophthalocyanines to the bulk material. Catalytic detection of dopamine, epinephrine, glucose and some pollutants using nanostructured metallophthalocyanine have been covered.

In vitro feasibility study of the use of a magnetic electrospun chitosan nanofiber composite for hyperthermia treatment of tumor cells

Hyperthermia has been reported to be an effective cancer treatment modality, as tumor cells are more temperature-sensitive than their normal counterparts. Since the ambient temperature can be increased by placing magnetic nanoparticles in an alternating magnetic field it has become of interest to incorporate these magnetic nanoparticles into biodegradable nanofibers for possible endoscopic hyperthermia treatment of malignant tumors. In this preliminary investigation we have explored various characteristics of biodegradable electrospun chitosan nanofibers containing magnetic nanoparticles prepared by different methods. These methods included: (1) E-CHS-Fe(3)O(4), with electrospun chitosan nanofibers directly immersed in a magnetic nanoparticle solution; (2) E-CHS-Fe(2+), with the electrospun chitosan nanofibers initially immersed in Fe(+2)/Fe(+3) solution, followed by chemical co-precipitation of the magnetic nanoparticles. The morphology and crystalline phase of the magnetic electrospun nanofiber matrices were determined by scanning electron microscopy, transmission electron microscopy, selected area electron diffraction, and X-ray diffraction spectroscopy. The magnetic characteristics were measured using a superconducting quantum interference device. The heating properties of these magnetic electrospun nanofiber matrices in an alternating magnetic field were investigated at a frequency of 750 kHz and magnetic intensity of 6.4 kW. In vitro cell incubation experiments indicated that these magnetic electrospun nanofiber matrices are non-cytotoxic and can effectively reduce tumor cell proliferation upon application of a magnetic field.