Films Of Prussian Blue Analogues Research Articles

Magnetic Properties of the Thin Films of Prussian Blue Analogues Obtained by Ion-Exchange Synthesis

Magnetic Properties of the Thin Films of Prussian Blue Analogues Obtained by Ion-Exchange Synthesis

In situ fabrication of CuO nanowire film for high-sensitive ascorbic acid recognition

One-dimensional metal oxides have been attracting interest as advanced materials for trace target recognition in chemical sensors due to their ultra-high surface area and electrochemical activity. However, the development of a large-scale and controllable fabrication strategy remains a great challenge and has hindered their practical application. In this work, we design a novel thermal oxidation route for obtaining a large area of CuO nanowires by the use of a film precursor of the nanocubic Cu-Fe Prussian blue analogue (PBA). The nanostructure and distribution of the PBA film was precisely controlled using an electrostatic self-assembly approach. The CuO nanowire shape was formed in-situ via the growth confinement effect through the air-heating collapse and oxidation of PBA crystals. At a very low working potential of 0.1 V, the as-prepared CuO nanowire sensor exhibited excellent sensing performance on ascorbic acid over a wide linear range (20–400 μM) and a low detection limit (0.5 μM), as well as high selectivity despite various interferences.

A breakthrough in the intrinsic multiferroic temperature region in Prussian blue analogues

Thin films of [(FeIIxCrII1−x)]1.5[CrIII(CN)6]·yH2O (x ≈ 0.30–0.35, y ≈ 1.77) (1) on FTO substrates (namely film 1) were synthesized with an electrochemical method. Investigation of the ferroelectricity of film 1 at different temperatures reveals that it exhibits ferroelectric behaviour in the temperature range from 10 K to 310 K. Study of the X-ray absorption (XAS) of the crushed film 1 and simulation of the structure of film 1 and crushed film 1 by using the Materials Studio software indicate that the vacancy defects and interactions between the film and FTO substrate make a key contribution to the ferroelectricity of film 1. Owing to the magnetic phase transition point being up to 210 K, film 1 is a multiferroic material and its magneto/electric coexistence temperature can be as high as 210 K.

Synthesis of Bidimensional Prussian Blue Analogue Using an Inverted Langmuir-Schaefer Method.

One of the aspects of modern materials science that has been captivating scientific interest for the past decade is low-dimensional systems. This stems from the fact that the physical, chemical, and biological properties of such systems are often vastly different from their bulk counterparts. Additionally, low-dimensionality structures frequently serve as a convenient platform for device applications. However, such materials are typically constructed from building blocks that are inherently three-dimensional, and so, from a morphological point of view, these can still be categorized as bulk powders or crystals. To push the boundaries of reduced dimensionality, we synthesized truly two-dimensional films of Prussian blue analogues (mixed valence tetracyanides) by combining an air-water interface reaction and a novel inverted Langmuir-Schaefer technique. The methodology introduced in this study offers control and tailoring over the Prussian blue analogues' film characteristics, which is an important step toward their incorporation into tangible applications. Standard isotherms were collected as a function of the initial reactant volume, and a number of characterization techniques such as X-ray photoelectron spectroscopy (XPS), UV-visible spectroscopy (UV-vis), transmission electron microscopy (TEM), selected area electron diffraction (SAED), and atomic force microscopy (AFM) were performed on films transferred on various substrates. The results indicated a collection of single-crystalline and polycrystalline flakes possessing different thicknesses and having a structural coherence length of 11 ± 3 nm.

Simultaneous determination of four local anesthetics by CE with ECL and study on interaction between procainamide and human serum albumin

A new method of capillary electrophoresis (CE) coupled with tris(2, 2′-bipyridyl) ruthenium(II) electrochemiluminescence (ECL) detection has been developed to detect four local anesthetics procainamide (PAH), tetracaine (TCH), proparacaine (PCH) and cinchocaine (CIN) simultaneously. An europium (III)-doped prussian blue analogue film (Eu-PB) modified platinum electrode was prepared and applied to improve the detection sensitivity. The parameters including additives, concentration and pH of the running buffer, separation voltage and detection potential that affect CE separation and ECL detection were optimized in detail. The four local anesthetics were baseline separated and detected within 10min under the optimized conditions. The detection limits (LOD) of PAH, TCH, PCH and CIN are 5.5×10−8, 9.6×10−8, 2.5×10−8 and 3.5×10−8molL−1 (S/N=3), respectively. RSDs of the migration time for four analytes range from 1.2% to 2.5% within intraday and from 2.4% to 4.9% in interday, RSDs of the peak area for four analytes are from 1.7% to 3.3% within intraday and from 2.2% to 5.6% in interday, respectively. The limits of quantitation (LOQ) (S/N=10) for PAH, TCH, PCH and CIN in human urine sample are 5.9×10−7, 9.2×10−7, 8.3×10−7 and 5.0×10−7molL−1, separately. The recoveries (n=3) of four analytes in human urine are from 87.6% to 107.7% with less than 5.9% in RSDs. The developed method was used to determine four local anesthetics in human urine samples and investigate the interaction between PAH and human serum albumin (HSA). The number of binding sites and the binding constant of PAH with HSA were calculated to be 1.03 and 2.4×104Lmol−1, respectively.

Simultaneous determination of lappaconitine hydrobromide and isopropiram fumarate in rabbit plasma by capillary electrophoresis with electrochemiluminescence detection

A CE electrochemiluminescence (CE-ECL) method for simultaneous determination of lappaconitine hydrobromide (LH) and isopropiram fumarate (IF) has been first established, with a chemically modified platinum electrode by europium (III)-doped Prussian blue analogue film as a working electrode. The conditions for CE separation and ECL detection are discussed and optimized in detail. It has been proved that 20 mmol/L phosphate buffer (pH 8.5) containing 5% (v/v) ACN and 0.17 mol/L SDS could achieve the most favorable resolution, and the high sensitivity of detection was obtained by maintaining the detection potential at 1.23 V. Under optimized conditions, a baseline separation for the two analytes was achieved within 6 min, and the standard curves were linear in the range of 1.0×10(-7) ~ 5.0 × 10(-5) g/mL for LH and 4.0 × 10(-8) ~ 1.0 × 10(-5) g/mL for IF with the detection limits (3σ) of 6.6 × 10(-8) g/mL for LH and 3.7 × 10(-8) g/mL for IF, respectively. The precisions of intra- and interday measurements for LH and IF were less than 4.21 and 2.61%, respectively. The applicability of the proposed method was illustrated in the determination of LH and IF in rabbit plasma with recoveries between 95.6 and 103.0%.

Tailoring magnetic properties of electrodeposited thin films of the molecule-based magnet Cr5.5(CN)12 11.5H2O.

This paper reports on molecular-based magnetic thin films of Prussian blue analogues (PBA) with high critical temperatures composed of mixed-valence chromium cyanides. The thin films of PBA were synthesized by means of electrodeposition technique. Morphology and magnetic study are presented in a function of electrochemical deposition conditions. We present the electrochemical methods as a promising and effective tool for preparing molecular-based magnetic thin films of Prussian blue analogue.

Magnetic anisotropy in thin films of Prussian blue analogues

The magnetic anisotropy of thin $(\ensuremath{\sim}200\text{ }\text{nm})$ and thick $(\ensuremath{\sim}2\text{ }\ensuremath{\mu}\text{m})$ films and of polycrystalline (diameters $\ensuremath{\sim}60\text{ }\text{nm}$) powders of the Prussian blue analogue ${\text{Rb}}_{0.7}{\text{Ni}}_{4.0}{[\text{Cr}{(\text{CN})}_{6}]}_{2.9}\ensuremath{\cdot}n{\text{H}}_{2}\text{O}$, a ferromagnetic material with ${T}_{c}\ensuremath{\sim}70\text{ }\text{K}$, have been investigated by magnetization, ESR at 50 and 116 GHz, and variable-temperature x-ray diffraction (XRD). The origin of the anisotropic magnetic response cannot be attributed to the direct influence of the solid support but the film growth protocol that preserves an organized two-dimensional film is important. In addition, the anisotropy does not arise from an anisotropic $g$ tensor nor from magnetolattice variations above and below ${T}_{c}$. By considering effects due to magnetic domains and demagnetization factors, the analysis provides reasonable descriptions of the low- and high-field data, thereby identifying the origin of the magnetic anisotropy.

A New Material Based on Nanostructured Prussian Blue Analogue Film Doped with Ce(III) for Development of Hydrogen Peroxide Sensor

AbstractPrussian blue analogue nanoparticles doped with Ce(III) (CeHCF) have been synthesized using chitosan (CS) and poly(diallyldimethylammonium chloride) (PDDA) as protective matrix and were cast onto a glassy carbon electrode surface directly. Transmission electron microscopy, UV‐Vis absorption spectroscopy and resonance Rayleigh scattering technique were employed to characterize the PB analogue nanoparticles protected with CS and PDDA. Compared with the bare glassy carbon electrode, the modified electrode exhibited excellent performances for determining H2O2. This work demonstrates the feasibility of the CS‐PDDA‐CeHCF nanoparticles modified glassy carbon electrode for practical sensing applications.

Metal-to-ligand and ligand-to-metal charge transfer in thin films of Prussian blue analogues investigated by X-ray absorption spectroscopy

A series of thin films of Prussian blue analogues is investigated by X-ray absorption spectroscopy (XAS) at the Fe, Co and Mn L(2,3)-edges. The ligand field multiplet theory enables us to examine accurately the electronic structure of these materials. Experimental XAS spectra of CoFe Prussian blue analogues are successfully reproduced using a ground state configuration including metal-to-ligand (MLCT) and ligand-to-metal charge transfer (LMCT) at the Co and Fe L(2,3)-edges. In particular, a huge improvement is achieved for satellite peaks at the Co(iii) L(2,3)-edges compared to previous calculations in the literature based on LMCT effects only. On the other hand, XAS spectra of MnFe analogues synthesized for the first time, can be reproduced conveniently by taking into account either MLCT or LMCT depending on the conditions of the sample preparation. For each thin film, the proportion of the different oxidation states of Co, Fe and Mn is evaluated. Unexpectedly, this analysis reveals the presence of a significant amount of a reduced phase, which turns out to be strongly dependent on the sample synthesis and storage conditions.

Characteristic and electrocatalytic behavior of ruthenium Prussian blue analogue film in strongly acidic media

The remarkable stability of ruthenium Prussian blue analogue (designated as RuOx–PB) in strongly acidic media and for the enzymeless electrocatalytic oxidation of glucose was demonstrated in this study. The RuOx–PB combinative film neither dissolves nor denatures in concentrated acids, such as HClO4, HCl, H2SO4, and HNO3, investigated in this study. The catalytic response was found to directly proportional to [H+]. Such features are unique since neither RuOx- nor PB-based compounds are effective for direct carbohydrate oxidation in acidic media. The RuOx–PB film showed a highly reversible redox peak at ∼1.2V in 5M HClO4 as a result of the fast proton-coupled electron transfer behavior of high valent ruthenium intermediate, RuVII/VI. The formation of internal multiple-hydrogen bond as well as the generation of the 〉RuVIIO species in strongly acidic media were proposed to play a key role in this feature. The RuOx–PB holds high potential for use in catalytic oxidation, corrosion protection, biofuel cell, etc.