Prussian Blue Crystals Research Articles

Spiral-Concave Prussian Blue Crystals with Rich Steps: Growth Mechanism and Coordination Regulation.

Investigating the formation and transformation mechanisms of spiral-concave crystals holds significant potential for advancing innovative material design and comprehension. We examined the kinetics-controlled nucleation and growth mechanisms of Prussian Blue crystals with spiral concave structures, and constructed a detailed crystal growth phase diagram. The spiral-concave hexacyanoferrate (SC-HCF) crystals, characterized by high-density surface steps and a low stress-strain architecture, exhibit enhanced activity due to their facile interaction with reactants. Notably, the coordination environment of SC-HCF can be precisely modulated by the introduction of diverse metals. Utilizing X-ray absorption fine structure spectroscopy and in situ ultraviolet-visible spectroscopy, we elucidated the formation mechanism of SC-HCF to Co-HCF facilitated by oriented adsorption-ion exchange (OA-IE) process. Both experimental data, and density functional theory confirm that Co-HCF possesses an optimized energy band structure, capable of adjusting the local electronic environment and enhancing the performance of the oxygen evolution reaction. This work not only elucidates the formation mechanism and coordination regulation for rich steps HCF, but also offers a novel perspective for constructing nanocrystals with intricate spiral-concave structures.

Spiral‐Concave Prussian Blue Crystals with Rich Steps: Growth Mechanism and Coordination Regulation

AbstractInvestigating the formation and transformation mechanisms of spiral‐concave crystals holds significant potential for advancing innovative material design and comprehension. We examined the kinetics‐controlled nucleation and growth mechanisms of Prussian Blue crystals with spiral concave structures, and constructed a detailed crystal growth phase diagram. The spiral‐concave hexacyanoferrate (SC‐HCF) crystals, characterized by high‐density surface steps and a low stress‐strain architecture, exhibit enhanced activity due to their facile interaction with reactants. Notably, the coordination environment of SC‐HCF can be precisely modulated by the introduction of diverse metals. Utilizing X‐ray absorption fine structure spectroscopy and in situ ultraviolet‐visible spectroscopy, we elucidated the formation mechanism of SC‐HCF to Co‐HCF facilitated by oriented adsorption‐ion exchange (OA‐IE) process. Both experimental data, and density functional theory confirm that Co‐HCF possesses an optimized energy band structure, capable of adjusting the local electronic environment and enhancing the performance of the oxygen evolution reaction. This work not only elucidates the formation mechanism and coordination regulation for rich steps HCF, but also offers a novel perspective for constructing nanocrystals with intricate spiral‐concave structures.

Self-Sustained-Release Strategy Realizes Colloid Oriented Assembly to Fabricate Prussian Blue with Hierarchical Structure.

The controlled self-assembly of nanomaterials has been a great challenge in nanosynthesis, especially for hierarchical architectures with high complexity. Particularly, the structural design of Prussian blue (PB) series materials with robustness and fast nucleation is even more difficult. Herein, a self-sustained-release strategy based on the slow release of metal ions from coordination ions is proposed to guide the assembly of PB crystals. The key to this strategy is the slow release by ligand, which can create ultra-low concentrations of metal ions so as to provide the possibility to realize the surface charge manipulation of PB primary colloids. By adding electrolyte or changing the polarity of the solution, the surface charge regulation of PB colloid is realized, and the PB hierarchical structures with branch fractal structure (PB-BS), octahedral fractal structure, and spherical fractal structure are effectively constructed. This work not only achieves the designability of the PB structure, but also synchronizes the functionalization during the PB assembly growth process by in situ encapsulation of the effective catalytic active component L-Ascorbic acid. As a result, the assembled PB-BS exhibits greatly enhanced catalytic activity and selectivity in styrene oxidation with the selectivity of oxidized styrene increasing from 35.6% (PB) to 80.5% (PB-BS).

Enzyme-catalyzed deposition of polydopamine for amplifying the signal inhibition to a novel Prussian blue-nanocomposite and ultrasensitive electrochemical immunosensing

The uncontrollable synthesis of Prussian blue (PB) and its weak stability toward OH– are great challenges affecting its electrochemical biosensing application. Herein we utilize the unique properties of chitosan (CS) to realize the facile and controllable synthesis of a CS-PB nanocomposite and combine it with the urease-catalyzed deposition of polydopamine (PDA) for amplifying the electrochemical signal inhibition of PB to develop a novel immunosensing method for protein detection. The immunosensor was constructed on a CS-PB modified electrode, and a urease-functionalized silica nanoprobe was prepared for tracing its sandwich immunoassay toward the model analyte of carcinoembryonic antigen. Besides the electrochemical impedance effect of the quantitatively captured nanoprobes, their enzymatic reaction can release numerous OH– to destroy the PB crystals and also induce the PDA deposition onto the immunosensor. These caused drastic electrochemical signal inhibition to PB. Based on the above multi-signal amplification mechanism, the method exhibits a very low detection limit of 0.042 pg mL–1 along with a very wide linear range of six-order of magnitude. In addition, the CS-PB based immunosensor has excellent specificity, repeatability, stability and reliability. Thus this PB nanocomposite and the proposed electrochemical immunosensing method reveal a promising potential for future applications.

Achieving a Zn-ion battery-capacitor hybrid energy storage device with a cycle life of more than 12,000 cycles

Prussian blue is considered as a promising zinc ion battery material because of its advantages such as stable structure, large lattice gap and simple preparation process. However, the poor conductivity seriously hinders the application of Prussian blue electrode materials. Herein we report a simple and interesting strategy to grow Prussian blue nanoparticle on expanded graphite electrode through a facile electrochemical method. Thanks to the synergy between Prussian blue analogue nanoparticles and self-supporting graphite flakes, the composite electrode with unique architectural structure possess both battery and capacitor characteristics. What's even more interesting is that the defects of Prussian blue crystals are gradually reduced during the extraction and insertion of zinc ions, and then the increasingly perfect crystal structure result in excellent cycling performance (120% capacitance retention after 12,000 cycles).

High‐Capacity Sodium–Prussian Blue Rechargeable Battery through Chelation‐Induced Nano‐Porosity

AbstractAcross the different classes of sodium‐ion battery cathodes, Prussian Blue holds the greatest promise because of its high working potentials, abundance, low‐toxicity and ease of synthesis. However, its performance as a sodium‐ion battery cathode has generally been limited to less than 120 mAh g−1, which is inferior compared to commercial lithium‐based counterparts. Here, sodium–Prussian Blue rechargeable batteries with a remarkably high discharge specific capacity of 153 ± 6 mAh g−1 at 1C is reported. This is achieved through the employment of excess ascorbic acid during the colloidal preparation of Prussian Blue crystals, followed by a 200 °C heat‐vacuum drying process. The optical, structural and thermogravimetric investigations show that the chelation of ascorbic acid to the iron ions disrupts the growth of Prussian Blue, and lead to the formation of a useful nano‐porous crystal structure. This allows for deeper percolation of sodium ions into the Prussian Blue crystals, and successfully unlocked useful inner volumes that are otherwise unreachable, thereby leading to an outstanding 47% elevation in specific capacity. This development brings sodium‐based battery technology significantly closer to the incumbent lithium‐ion batteries, and marks an important early step towards its practical application in commercial devices.

High-performance aqueous rechargeable potassium batteries prepared via interfacial synthesis of a Prussian blue-carbon nanotube composite

Aqueous rechargeable batteries are sustainable energy storage devices with the potential to replace the current state-of-the-art organic phase secondary batteries. Electrode materials for secondary batteries are often based on composite structures, which combine an electronically conducting scaffold with an ionic conductor, whose properties define battery capacity. Optimal integration of these components can be challenging: here we describe a novel approach to prepare electrode materials based on growth at the liquid-liquid interface. This is illustrated with the synthesis of a carbon nanotube/Prussian blue nanocomposite as free-standing transparent thin films, which are applied as cathodes for aqueous rechargeable potassium batteries. Prussian blue is synthesized through an acid-induced decomposition of ferricyanide, promoted by an interfacial electron transfer from an organic phase donor (1,1′-dimethylferrocene) under ambient conditions. The interfacial synthesis yields selective growth of cubic Prussian blue crystals on the carbon nanotube walls, enhancing interaction between the ionic and electronically conducting components, and resulting in a self-assembled film at the liquid/liquid interface. The films are readily transferred to flexible membranes and applied as cathodes in an aqueous rechargeable K+ battery. Coin-cell devices with activated carbon anodes gave a capacity of 47.6 mAh g−1 at 0.25 A g−1 with an energy density of 33.75 Wh kg−1

A Three Dimensional Conductive Matrix of Activated Carbon Coated Copper-Cobalt Prussian Blue Material for Sodium Ion Supercapacitors

In this work, a three dimensional (3D) conductive material of activated carbon coating Copper-Cobalt Prussian Blue (PB) is synthesized and applied on sodium ion supercapacitors. The activated carbon is proved able to enhance the conductivity, prevent structural collapse during sodium ion deintercalation, reduce interstitial water in PB crystals as well as special hindrance, and improve electrochemical performance of super capacitors dramatically. It is demonstrated that a specific capacity of 90.4 F g−1 and and power density of 4.3 kW kg−1 as well as energy density of 65.1 Wh kg−1 are achieved for CuCoHCF@ AC//AC device. In addition, 90% % starting value are retained for the specific capacity after 2000 cycles operation.

Stabilization of Prussian blue using copper sulfate for eliminating radioactive cesium from a high pH solution and seawater

Prussian blue (PB), an adsorbent for the selective elimination of radioactive cesium from water, is highly versatile due to its unique crystal structure. However, PB crystals quickly decompose in an alkaline solution, generating hazardous cyanide contamination. In this research, the alkaline susceptibility of PB was remedied by incorporating copper sulfate as a protector. A stability assessment was conducted at several environmental conditions, such as high pH and temperatures from 10 °C to 50 °C, in seawater, artificial seawater, and river water. The crystalline and chemical stability of PB in the new class of composite was extremely high, even at a pH value of 11.2, as confirmed using XRD and total cyanide analysis. A comprehensive mechanism study revealed that, at high pH, the copper ions that cover the PB react with hydroxide ions to form copper hydroxide and shielding inner crystals. To decontaminate radioactive cesium, the first step was to immobilize nano PB on a cellulose nanofiber, followed by copper sulfate stabilization. Then, a spongiform adsorbent was made using polyurethane as the precursor. The new stabilized PB showed promising adsorption efficiency. Thus, this research will open a new range of applications for all existing and emerging PB-based adsorbents.

Synthesis of Mesoporous Yolk-Shell Magnetic Prussian Blue Particles for Multi-Functional Nanomedicine.

Mesoporous magnetic Prussian Blue (PB) particles are good condidates for theragnostic nanomedicine. However, there are lack of efficient methods for fabrication of such materials. Here, we reported the synthesis of the mesoporous yolk-shell Fe3O4@PB particles by one-pot coordination replication and etching. Time-dependent transmission electron microscopy illustrated that the PB crystals nucleated and grew on the surface of Fe3O4 spheres by coordination replication with the help of protons. The extra protons in the reaction medium further disassociated the Fe3O4 and PB, leading to mesoporous particles. The mesoporous yolk-shell Fe3O4@PB particles showed enhanced efficacy for loading cisplatin. The release of the drug molecules could be facilitated by increasing temperature. Both photo irradiation and alternating magnetic fields could trigger the release of heat from the composite. The obtained materials could delivery cisplatin to kill cancer cell intracellularly.

Cubic Prussian blue crystals from a facile one-step synthesis as positive electrode material for superior potassium-ion capacitors

Cubic Prussian blue (PB) crystals are prepared by a facile one-step synsthesis. The structure and morphology of the as-prepared samples are characterized by X-ray power diffraction, inductively coupled plasma, scanning electron microscopy and electrochemical measurement. The PB electrode exhibits superior electrochemical behavior in K2SO4 aqueous solution including high reversible capacity (80 mAh g−1 at the current density of 0.5 A g−1), outstanding rate capability and good cycling stability. The K-ion capacitor (KIC) is also fabricated by using PB as a positive electrode and commercial activated carbon as an negative electrode, and it presents a maximum energy density of 28 Wh kg−1 at the current density of 1 A g−1 (corresponding to 7.5mA cm−2). Furthermore, the KIC also exhibits excellent cycling stability at the current density of 2 A g−1 with capacity retention of nearly 98% over 1200 cycles. Our synthesized electrode material provides a new way for fabricating high performance electrode materials for superior KIC.

Subzero-Temperature Cathode for a Sodium-Ion Battery.

A subzero-temperature cathode material is obtained by nucleating cubic prussian blue crystals at inhomogeneities in carbon nanotubes. Due to fast ionic/electronic transport kinetics even at -25 °C, the cathode shows an outstanding low-temperature performance in terms of specific energy, high-rate capability, and cycle life, providing a practical sodium-ion battery powering an electric vehicle in frigid regions.

ChemInform Abstract: New Faces of Porous Prussian Blue: Interfacial Assembly of Integrated Hetero‐Structures for Sensing Applications

AbstractReview: 258 refs.

High-quality Prussian blue crystals as superior cathode materials for room-temperature sodium-ion batteries

High-quality Prussian blue crystals with a small number of vacancies and a low water content show high specific capacity and remarkable cycle stability as cathode materials for Na-ion batteries.

Thermal decomposition of Prussian Blue microcrystals and nanocrystals – iron(iii) oxide polymorphism control through reactant particle size

We present the first direct evidence that reactant particle size determines the mechanism of thermally induced solid-state reactions and can be used as the tuner of the product crystal structure. This control of the polymorphous character of the products through the particle size of precursor is demonstrated upon following the process of isothermal decomposition of Prussian Blue at 350 °C in air. The reaction mechanism was studied by 57Fe Mossbauer spectroscopy, X-ray powder diffraction, magnetization measurements, and transmission and scanning electron microscopy. The decomposition of Prussian Blue nanoparticles (10–15 nm) gave preferential formation of γ-Fe2O3 nanoparticles (10–20 nm), while Prussian Blue microcrystals (20–50 μm) afforded formation of β-Fe2O3 nanoparticles (50–70 nm). The final polymorphous composition of the iron(III) oxide product is thought to be driven by the different diffusion conditions for penetration of the reaction gas (oxygen) into the Prussian Blue crystals as well as release of the gas (dicyane) during the Prussian Blue decomposition. Therefore, the reactant particle size control provides a new method for the large-scale preparation of rare β-Fe2O3 nanoparticles.

Layer-by-layer Self-assembled Prussian Blue Modified Electrode and Its Application for the Detection of Hydrogen Peroxide

Para aminobenzene sulfonic acid(p-ABSA) was deposited onto the surface of a glass carbon electrode(GCE) through the electrochemical deposition.Cation-exchange properties of the deposited p-ABSA were then employed to confine ferric ion(Fe3+) within the polymeric layer.Ferrocyanide ions([Fe(CN)6]4-) can react with the adsorbed Fe3+ forming Prussian blue(PB).PB crystals were formed by alternative adsorption of Fe3+ and reaction with [Fe(CN)6]4-.The crystal shows high catalytic activity toward the electrochemical reduction of hydrogen peroxide.Cyclic voltammetry,electrochemical impedance spectroscopy and typical amperometric response method were employed to characterize the electrochemical properties of the PB modified electrode.The experimental parameters(applied potential,pH,and interfering substances) influencing the performance of the PB modified electrode were investigated in details.Under optimal conditions,the PB modified electrode exhibits a wider linear range of 0.97~32.33 mmol/L with the fast response less than 5 s and a low detection limit of 0.48 mmol/L(S/N=3).

Synthesis of Prussian Blue Nanoparticles and Nanocrystal Superlattices in Reverse Microemulsions We thank the Swiss National Science Foundation for a postdoctoral fellowship to S.V. and the University of Bristol for a postgraduate studentship to M.L.

Controlled growth of molecular magnets, in terms of their size, shape, and organization, is demonstrated with a model cyanometallate, Prussian blue crystals. The TEM image shows the hydrophobic cubic nanoparticles (scale bar 100 nm), prepared in a microemulsion and encapsulated in a shell of surfactant, which readily self-assemble into the higher-order square superlattice.

Free-space marker studies on the leaves of Saccharum officinarum and Bromus unioloides

Two free-space marker procedures (Prussian blue and lead nitrate) were used on leaves of Saccharum officinarum L. and Bromus unioloides H.B.K. to determine (1) the pathway(s) followed by water and solutes in the transpiration stream after their introduction into the xylem of small and intermediate vascular bundles, and (2) the effectiveness of the suberin lamellae of the chlorenchymatous bundle-sheath (in S. officinarum ) and mestome sheath (in B. unioloides ) cells as a barrier to the movement of tracer ions (Fe 3 + and Pb 2 + ). Judged from the distribution of Prussian blue crystals and lead deposits, water and tracer ions moved readily from the lumina of the vessels into the phloem apoplast via portions of vessel primary walls not bearing lignified secondary wall thickenings in both species. Prussian blue crystals and lead deposits were abundant on both sides of the suberin lamella of the chlorenchymatous bundle-sheath/mesophyll interface in S. officinarum and the mestome sheath/parenchymatous bundle sheath interface in B. unioloides. Prussian blue crystals and lead deposits were lacking entirely, however, in the suberin lamellae, indicating that the lamellae were fairly Impermeable to the tracer ions. The presence of Prussian blue crystals and lead deposits in the compound middle lamellae of the radial walls of the chlorenchymatous bundle-sheath cells of S. officinarum and the mestome sheath cells of B. unioloides indicates that the compound middle lamella provides an apoplastic pathway for transpirational water and solutes from small and intermediate bundles to the contiguous tissues in both species.

Measurement of CO2 and H2O Vapor Exchange in Spinach Leaf Discs

A leaf chamber has been designed which allows the measurement of both CO(2) and water vapor exchange in Spinacia oleracea leaf discs. The center of the disc lies within a cylindrical gas chamber and its margins are enclosed within a cavity through which water or various metabolites can be pumped. In saturating light and normal atmospheres, the leaf discs have a relatively low resistance to H(2)O vapor transfer (r(w) = 1.87 seconds per centimeter) and can support high rates of photosynthesis for several hours. The abaxial surface of a disc had a higher resistance to water vapor transfer (r(w) = 3.22 seconds per centimeter) than the adaxial (r(w) = 2.45 seconds per centimeter) despite having a higher stomatal frequency (abaxial, 105/square millimeter; adaxial, 58/square millimeter). In 2% O(2), the discs required an internal concentration of CO(2) of 115 microliters per liter to support one-half of the maximal velocity of apparent photosynthesis (average value, 66 milligrams CO(2) per square decimeter per hour). In 20% O(2), the comparable values are 156 microliters per liter and 56 milligrams CO(2) per square decimeter per hour. In air, apparent photosynthesis saturated at intensities (750 microeinsteins per square meter per second) well below that of daylight but, when the internal CO(2) was raised to 700 to 900 microliters per liter, photosynthesis was not saturated even at daylight intensities (2025 microeinsteins per square meter per second). The distribution of Prussian blue crystals, formed after ferrocyanide feeding, showed that water entered the disc via the vasculature. When 25-minute pulses of orthophosphate were provided in the feeding solution, there were concentration-dependent increases in both r(w) and r(m) leading to inhibition of photosynthesis. The orthophosphate-dependent inhibitions were reversible.

The suberin lamella, a possible barrier to water movement from the veins to the mesophyll ofThemeda triandra forsk

Precipitation of ferrous ions by ferricyanide in transpiring leaves ofThemeda triandra Forsk. produced crystalline deposits, which were visible with the light and electron microscope. Prussian blue crystals were formed within the lumina of the tracheary elements and the apoplast, or cell wall continuum of the vascular tissues and bundle-sheath cells. Little if any deposition was noted within the lignified secondary thickenings of the tracheary elements. The localization pattern suggests that the ferrous ions moved from the lumina of the tracheary elements via the exposed primary walls. Prussian blue crystals were abundant in the outer tangential and radial walls of the bundle-sheath cells. By contrast, crystals were lacking in the walls of neighbouring mesophyll cells, suggesting that the suberin lamella in the bundle-sheath walls effectively inhibited the apoplastic movement of ferrous ions and possibly may impede, or restrict the movement of water across the bundle-sheath/mesophyll interface.