Cerium Hexacyanocobaltate: A Lanthanide-Compliant Prussian Blue Analogue for Li-Ion Storage

Prussian Blue Analogues-Derived Molecularly Imprinted Nanozyme Array for Septicemia Detection

Septicemia, a severe bacterial infection, poses significant risks to human health. Early detection of septicemia by tracking specific biomarkers is crucial for a timely intervention. Herein, we developed a molecularly imprinted (MI) TiO2-Fe-CeO2 nanozyme array derived from Ce[Fe(CN)6] Prussian blue analogues (PBA), specifically targeting valine, leucine, and isoleucine, as potential indicators of septicemia. The synthesized nanozyme arrays were thoroughly characterized using various analytical techniques, including Fourier transform infrared spectroscopy, X-ray diffraction, field-emission scanning electron microscope, and energy-dispersive X-ray. The results confirmed their desirable physical and chemical properties, indicating their suitability for the oxidation of 3,3',5,5'-tetramethylbenzidine serving as a colorimetric probe in the presence of a persulfate oxidizing agent, further highlighting the potential of these arrays for sensitive and accurate detection applications. The MITiO2 shell selectively captures valine, leucine, and isoleucine, partially blocking the cavities for substrate access and thereby hindering the catalyzed TMB chromogenic reaction. The nanozyme array demonstrated excellent performance with linear detection ranges of 5 μM to 1 mM, 10-450 μM, and 10-450 μM for valine, leucine, and isoleucine, respectively. Notably, the corresponding limit of detection values were 0.69, 1.46, and 2.76 μM, respectively. The colorimetric assay exhibited outstanding selectivity, reproducibility, and performance in the detection of analytes in blood samples, including C-reactive protein at a concentration of 61 mg/L, procalcitonin at 870 ng/dL, and the presence of Pseudomonas aeruginosa bacteria. The utilization of Ce[Fe(CN)6]-derived MITiO2-Fe-CeO2 nanozyme arrays holds considerable potential in the field of septicemia detection. This approach offers a sensitive and specific method for early diagnosis and intervention, thereby contributing to improved patient outcomes.

Effect of Static Jahn-Teller Distortion on the Li+ Transport in a Copper Hexacyanoferrate Framework

Prussian blue (PB) and its analogues (PBAs) are potential cathode-active materials for rechargeable lithium-ion batteries. Although a body of research has assessed the performances of various PB/PBA cathodes with an eye to practical use, the underlying Li⁺-transport mechanism is still unclear. Focusing on copper hexacyanoferrate (CuHCF), a PBA that exhibits static Jahn-Teller (JT) distortion, we theoretically investigate how the framework's distortion affects the pathways and energetics of the Li⁺ transport. Density functional theory calculations of a local structure model of CuHCF reveal that the static JT distortion makes the favorable Li⁺-transport pathways quasi-two-dimensional, contrary to an intuitive picture of isotropic Li⁺ diffusion within the regular jungle-gym framework. The pathways are mutually interconnected, thereby creating an almost barrierless transport network. To better understand the distortion-induced transport anisotropy, we visually analyze the framework's electronic structure and noncovalent Li⁺-framework interactions. This study helps deepen the fundamental understanding of intrinsic Li⁺-transport properties of a distorted porous framework.

Sea urchin-like CoNi2S4materials derived from nickel hexamyanocobaltate for high-performance asymmetric hybrid supercapacitor

In this work, a mild chemical precipitation method and simple hydrothermal treatment of the nickel hexamyanocobaltate precursor strategy are developed to prepare a sea urchin-like CoNi₂S₄compound with remarkable specific capacity and excellent cycling stability. The prepared CoNi₂S₄has an outstanding specific capacity of 149.1 mA h g^-1at 1 A g^-1and an initial capacity of 83.1% after 3000 cycles at 10 A g^-1. Moreover, the porous carbon nanospheres (PCNs) with exhibit cycling stability (94.7% of initial specific capacity after 10 000 cycles at 10 A g^-1) are selected as negative electrode to match CoNi₂S₄positive electrode for assembly of CoNi₂S₄//PCNs asymmetric supercapacitor (ASC). Satisfactorily, the as-assembled CoNi₂S₄//PCNs ASC exhibits an impressive energy density of 41.6 Wh kg^-1at 797 W kg^-1, as well as the suitable capacity retention of 82.8% after 10 000 cycles. The superior properties of the device demonstrated that the as-prepared material is potential energy storage material.

Polyaniline-Encapsulated Hollow Co-Fe Prussian Blue Analogue Nanocubes Modified on a Polypropylene Separator To Improve the Performance of Lithium-Sulfur Batteries

Recent studies of lithium-sulfur (Li-S) batteries have identified that a modified separator plays a critical role in challenging the capacity fading and shuttle effect of lithium polysulfides (LiPSs). Herein, we report a polyaniline-encapsulated hollow Co-Fe Prussian blue analogue (CFP@PANI) for separator modification. The open frame-like hollow CFP was synthesized via oriented attachment (OA). To improve the catalytic effect and electrical conductivity, PANI was coated on the synthesized CFP. The resulting CFP@PANI was applied on the conventional polypropylene (PP) separator (CFP@PANI-PP) with vacuum filtration. With a ketjen black/sulfur (KB/S) cathode with 66% of the sulfur load, the CFP@PANI-PP exhibited an initial capacity of 723.1 mAh g^-1 at a current density of 1 A g^-1. Furthermore, the CFP@PANI-PP showed stable cycling performance with 83.5% capacity retention after 100 cycles at 1 A g^-1. During the 100 cycles, each cycle maintained high coulombic efficiency above 99.5%, which indicates that the CFP@PANI-PP could inhibit LiPS migration to the anode side without a Li⁺ transport disturbance across the separator. Overall, the CFP@PANI-PP efficiently suppressed LiPSs, resulting in enhanced electrochemical performance. The current study provides useful insight into designing a nanostructure for separator modification of Li-S batteries.

Diverse physical functionalities of rare-earth hexacyanidometallate frameworks and their molecular analogues

The combination of rare-earth metal complexes and hexacyanidometallates of transition metals is a fruitful pathway for achieving functional materials exhibiting a wide scope of mechanical, magnetic, optical, and electrochemical properties.

Solvent-assisted synthesis of dendritic cerium hexacyanocobaltate and derived porous dendritic Co3O4/CeO2 as supercapacitor electrode materials

Here, we report a solvent-mediated synthetic route for preparing cerium hexacyanocobaltate with a dendritic shape. The porous dendritic Co₃O₄/CeO₂ was prepared after annealing at 500 °C, served as a supercapacitor electrode.

Developments and applications of nanomaterial-based carbon paste electrodes

This review summarizes the progress that has been made in the past ten years in the field of electrochemical sensing using nanomaterial-based carbon paste electrodes. Following an introduction into the field, a first large section covers sensors for biological species and pharmaceutical compounds (with subsections on sensors for antioxidants, catecholamines and amino acids). The next section covers sensors for environmental pollutants (with subsections on sensors for pesticides and heavy metal ions). Several tables are presented that give an overview on the wealth of methods (differential pulse voltammetry, square wave voltammetry, amperometry, etc.) and different nanomaterials available. A concluding section summarizes the status, addresses future challenges, and gives an outlook on potential trends.

Recent developments in conducting polymers: applications for electrochemistry

Scientists have categorized conductive polymers as materials having strongly reversible redox behavior and uncommon combined features of plastics and metal. Because of their multifunctional characteristics, e.g., simplistic synthesis, acceptable environmental stability, beneficial optical, electronic, and mechanical features, researchers have largely considered them for diverse applications. Therefore, their capability of catalyzing several electrode reactions has been introduced as one of their significant features. A thin layer of the conducting polymer deposited on the substrate electrode surface can augment the electrode process kinetics of several solution species. Such electrocatalytic procedures with modified conducting polymer electrodes can create beneficial utilization in diverse fields of applied electrochemistry. This review article explores typical recent applications of conductive polymers (2016–2020) as active electrode materials for energy storage applications, electrochemical sensing, and conversion fields such as electrochemical supercapacitors, lithium-ion batteries, fuel cells, and solar cells.

Scientists have categorized conductive polymers as materials having strongly reversible redox behavior and uncommon combined features of plastics and metal.

Direct electrochemical detection of clozapine by RuO2 nanoparticles-modified screen-printed electrode

This study introduces the sensitive electrochemical detection of clozapine with the use of a ruthenium(iv) oxide nanoparticle (RuO₂ NP)-modified screen-printed electrode (RuO₂ NPs/SPE).