Search

The main challenge for aqueous zinc‐ion capacitors is the low stability of zinc anode. In this study, a Prussian blue analog (PBA) has been coated on the surface of zinc foil to create an inorganic protective layer. This layer features a three‐dimensional open microporous structure, which not only endows it with excellent pseudocapacitive properties but also serves as an effective barrier against dendrite growth. The presence of PBA coating can increase the nucleation point of zinc ions and provide a low‐energy barrier for the rapid migration of zinc ions. Hence, the PBA@Zn ||PBA@Zn symmetric cell exhibits exceptional cycling stability, enduring over 1400 h of operation at a current density of 1 mA cm−2 and a capacity of 1 mAh cm−2. The PBA@Zn||AC capacitor demonstrated a discharge capacity of 46.23 mAh g−1 after 10 000 cycles at a current density of 1 A g−1, with a capacity retention of 92.41%, whereas the discharge capacity of Zn||AC capacitor is only 16.02 mAh g−1, with a capacity retention of 23.13%. The PBA@Zn||AC capacitor exhibited remarkable endurance and stability, retaining a substantial discharge capacity of 32.7 mAh g−1 after 10 000 cycles at 10 A g−1. Density Functional Theory (DFT) calculations also show that PBA has a strong interaction with Zn and exhibits superior zincophilic ability. This study reports industrially applicable low‐cost Prussian blue analogs as artificial interfacial protective layers for improving the cycling stability of zinc anode with a low‐energy barrier for rapid migration of zinc ions especially at high current density. [ABSTRACT FROM AUTHOR]

The electrochemical splitting of water for hydrogen production faces a major challenge due to its anodic oxygen evolution reaction (OER), necessitating research on the rational design and facile synthesis of OER catalysts to enhance catalytic activity and stability. This study proposes a ligand‐induced MOF‐on‐MOF approach to fabricate various trimetallic MnFeCo‐based Prussian blue analog (PBA) nanostructures. The addition of [Fe(CN)6]3− transforms them from cuboids with protruding corners (MnFeCoPBA‐I) to core–shell configurations (MnFeCoPBA‐II), and finally to hollow structures (MnFeCoPBA‐III). After pyrolysis at 800 °C, they are converted into corresponding PBA‐derived carbon nanomaterials, featuring uniformly dispersed Mn2Co2C nanoparticles. A comparative analysis demonstrates that the Fe addition enhances catalytic activity, while Mn‐doped materials exhibit excellent stability. Specifically, the optimized MnFeCoNC‐I‐800 demonstrates outstanding OER performance in 1.0 m KOH solution, with an overpotential of 318 mV at 10 mA cm−2, maintaining stability for up to 150 h. Theoretical calculations elucidate synergistic interactions between Fe dopants and the Mn2Co2C matrix, reducing barriers for oxygen intermediates and improving intrinsic OER activity. These findings offer valuable insights into the structure‐morphology relationships of MOF precursors, advancing the development of highly active and stable MOF‐derived OER catalysts for practical applications. [ABSTRACT FROM AUTHOR]

Metal alloys have garnered significant attention as electrocatalysts for the alkaline hydrogen evolution reaction due to their exceptional conductivity and durability. Herein, FeCo alloy nanoparticles are prepared on a carbon cloth skeleton by a low-temperature thermal technique with FeCo Prussian blue analog as the precursor. The strong electronic interactions between Co and Fe facilitate electron transferring from Fe to Co and play a crucial role in modulating hydrogen adsorption and accelerating charge transfer. The alloy exhibits outstanding catalytic activity, such as a small overpotential of 161 mV for a current density of 10 mA cm−2 in the 1.0 M KOH electrolyte as well as a Tafel slope of 104 mV dec−1. The catalyst can be operated continuously for 100 h at a current density of 100 mA cm−2 with minimal changes in the potential, morphology, and composition. The exceptional activity, stability, and synergistic effects provide valuable guidance to the design and fabrication of efficient and sustainable electrocatalysts for renewable energy applications. [Display omitted] • FeCo alloy nanoparticles are prepared on carbon cloth by low-temperature technique. • Strong electronic interactions between Co and Fe facilitate electron transfer. • Electron transfer from Fe to Co to modulate hydrogen adsorption behavior. • The FeCo needs an overpotential of 161 mV for a current density of 10 mA cm−2 • The catalyst shows no morphology or composition changes at 100 mA cm−2 for 100 h. [ABSTRACT FROM AUTHOR]

Prussian blue analogs (PBAs) are promising insertion‐type cathode materials for different types of aqueous batteries, capable of accommodating metal or non‐metal ions. However, their practical application is hindered by their susceptibility to dissolution, which leads to a shortened lifespan. Herein, we have revealed that the dissolution of PBAs primarily originates from the locally elevated pH of electrolytes, which is caused by the proton co‐insertion during discharge. To address this issue, the water‐locking strategy has been implemented, which interrupts the generation and Grotthuss diffusion of protons by breaking the well‐connected hydrogen bonding network in aqueous electrolytes. As a result, the hybrid electrolyte enables the iron hexacyanoferrate to endure over 1000 cycles at a 1 C rate and supports a high‐voltage pH‐decoupled cell with an average voltage of 1.95 V. These findings provide insights for mitigating the dissolution of electrode materials, thereby enhancing the viability and performance of aqueous batteries. [ABSTRACT FROM AUTHOR]

Liver fibrosis is a major risk factor for hepatocellular carcinoma origin, and its progression not only correlates with oxidative stress and inflammation, but also is encouraged by autophagy hold‐up. Therefore, new solutions to effectively attenuate oxidative stress and inflammation and coincidentally favor autophagy are highly demanded to reverse liver fibrosis, and even hamper its escalation into hepatocellular carcinoma. Herein, the porous manganese‐substituted Prussian blue (PMPB) analogs are harnessed to activate autophagy, scavenge reactive oxygen species (ROS), and suppress inflammation for liver fibrosis therapy. PMPB can effectively inhibit macrophage activation, facilitate macrophage autophagy, eradicate ROS, and blockade cellular cross‐talk, thus impeding further inflammation progression. Moreover, the favorable spontaneous capture of PMPB by Kupffer cells allows more PMPB accumulation in liver to significantly attenuate liver injury and collagen deposition, thereby inhibiting the progression of liver fibrosis. PMPB‐based nanomedicine shows great potentials in promoting autophagy activation, eliminating ROS, inhibiting inflammation, and protecting hepatocytes from oxidative stress‐arised damages, which eventually attenuate the extent of liver fibrosis, holding great promise in clinical translation for treating liver fibrosis. [ABSTRACT FROM AUTHOR]

Herein, we have designed a highly active and robust trifunctional electrocatalyst derived from Prussian blue analogs, where Co4N nanoparticles are encapsulated by Fe embedded in N‐doped carbon nanocubes to synthesize hierarchically structured Co4N@Fe/N–C for rechargeable zinc–air batteries and overall water‐splitting electrolyzers. As confirmed by theoretical and experimental results, the high intrinsic oxygen reduction reaction, oxygen evolution reaction, and hydrogen evolution reaction activities of Co4N@Fe/N–C were attributed to the formation of the heterointerface and the modulated local electronic structure. Moreover, Co4N@Fe/N–C induced improvement in these trifunctional electrocatalytic activities owing to the hierarchical hollow nanocube structure, uniform distribution of Co4N, and conductive encapsulation by Fe/N–C. Thus, the rechargeable zinc–air battery with Co4N@Fe/N–C delivers a high specific capacity of 789.9 mAh g−1 and stable voltage profiles over 500 cycles. Furthermore, the overall water electrolyzer with Co4N@Fe/N–C achieved better durability and rate performance than that with the Pt/C and IrO2 catalysts, delivering a high Faradaic efficiency of 96.4%. Along with the great potential of the integrated water electrolyzer powered by a zinc–air battery for practical applications, therefore, the mechanistic understanding and active site identification provide valuable insights into the rational design of advanced multifunctional electrocatalysts for energy storage and conversion. [ABSTRACT FROM AUTHOR]

Abstract Liver fibrosis is a major risk factor for hepatocellular carcinoma origin, and its progression not only correlates with oxidative stress and inflammation, but also is encouraged by autophagy hold‐up. Therefore, new solutions to effectively attenuate oxidative stress and inflammation and coincidently favor autophagy are highly demanded to reverse liver fibrosis, and even hamper its escalation into hepatocellular carcinoma. Herein, the porous manganese‐substituted Prussian blue (PMPB) analogs are harnessed to activate autophagy, scavenge reactive oxygen species (ROS), and suppress inflammation for liver fibrosis therapy. PMPB can effectively inhibit macrophage activation, facilitate macrophage autophagy, eradicate ROS, and blockade cellular cross‐talk, thus impeding further inflammation progression. Moreover, the favorable spontaneous capture of PMPB by Kupffer cells allows more PMPB accumulation in liver to significantly attenuate liver injury and collagen deposition, thereby inhibiting the progression of liver fibrosis. PMPB‐based nanomedicine shows great potentials in promoting autophagy activation, eliminating ROS, inhibiting inflammation, and protecting hepatocytes from oxidative stress‐arised damages, which eventually attenuate the extent of liver fibrosis, holding great promise in clinical translation for treating liver fibrosis.

Abstract Herein, we have designed a highly active and robust trifunctional electrocatalyst derived from Prussian blue analogs, where Co4N nanoparticles are encapsulated by Fe embedded in N‐doped carbon nanocubes to synthesize hierarchically structured Co4N@Fe/N–C for rechargeable zinc–air batteries and overall water‐splitting electrolyzers. As confirmed by theoretical and experimental results, the high intrinsic oxygen reduction reaction, oxygen evolution reaction, and hydrogen evolution reaction activities of Co4N@Fe/N–C were attributed to the formation of the heterointerface and the modulated local electronic structure. Moreover, Co4N@Fe/N–C induced improvement in these trifunctional electrocatalytic activities owing to the hierarchical hollow nanocube structure, uniform distribution of Co4N, and conductive encapsulation by Fe/N–C. Thus, the rechargeable zinc–air battery with Co4N@Fe/N–C delivers a high specific capacity of 789.9 mAh g−1 and stable voltage profiles over 500 cycles. Furthermore, the overall water electrolyzer with Co4N@Fe/N–C achieved better durability and rate performance than that with the Pt/C and IrO2 catalysts, delivering a high Faradaic efficiency of 96.4%. Along with the great potential of the integrated water electrolyzer powered by a zinc–air battery for practical applications, therefore, the mechanistic understanding and active site identification provide valuable insights into the rational design of advanced multifunctional electrocatalysts for energy storage and conversion.

Abstract Value‐added conversion of lignocellulose is a sustainable approach. Photo‐refining biomass is in line with current environmental protection strategies. However, photo‐reforming biomass suffers from poor catalyst stability and low conversion efficiency. Here, we designed fructose as a lignocellulosic model. The heterogeneous structure of Prussian blue coating was constructed with a special covalent bond structure of CoCNZn. This structure has a catalytic conversion mechanism that can accelerate electron transfer. Fructose was simultaneously converted to value‐added platform compounds (5‐HMF and formic acid) and gaseous fuels (CO, CH4) with a conversion rate of up to 92.5%, which is more than 1.7 times than that of catalysts without adding Prussian blue. Hydrogen transfer and carbon transfer on the carbon atoms of fructose facilitates the production and accelerates the spillover of CO from formic acid. This work provides new ideas for the development of Prussian blue catalysts and the conversion of pentose.

Fe‐based potassium Prussian blue analogs (K‐PBAs) are commonly used as K‐ion battery (KIB) cathodes. Interestingly, K‐PBAs are appealing cathodes for Na‐ion batteries (NIBs). In a hybrid NIB cell, where Na‐ion is in the electrolyte and K‐ion is in the PBA cathode, cation intercalation and electrochemical performance of the cathode can be significantly affected by [Fe(CN)6]4− anion vacancy. This work studies the effect of anion vacancy in K‐PBAs on regulating K‐ion/Na‐ion intercalation mechanism in hybrid NIB cells, by comparing two K‐PBA cathodes with different vacancy contents. The results demonstrate that introducing a level of anion vacancy can maximize the number of K‐ion intercalation sites and enhance K‐ion diffusion in the PBA framework. This facilitates K‐ion intercalation and suppresses Na‐ion intercalation, resulting in a K‐ion‐dominated and high‐discharge‐voltage ion storage process in the hybrid NIB cell. The K‐PBA cathode with 20% anion vacancy delivers 128 mAh g−1 at 25 mA g−1 and 67 mAh g−1 at 1000 mA g−1, as well as retains 89% and 81% capacity after 100 and 300 cycles, respectively. It completely outperforms the counterpart with 7% anion vacancy, which exhibits increased Na‐ion intercalation but overall deteriorated ion storage. [ABSTRACT FROM AUTHOR]

Prussian blue analogs (PBAs) and their derivatives have been extensively investigated as potential oxygen evolution reaction (OER) electrocatalysts due to their high specific surface areas, adjustable composition, and controllable morphology, yet they suffer from easy aggregation and poor electrical conductivity. Herein, we successfully synthesized PBA‐derived NiFe bimetallic phosphide nanoparticles encapsulated in porous nitrogen‐doped electrospun carbon nanofibers by sequential electrospinning, carbonization, and phosphorization. By exploring the effects of different phosphating temperatures on electrocatalytic performance, the obtained electrocatalyst possesses a low overpotential of 262 mV at 10 mA cm−2 for OER in 1.0 M KOH. The electrospun carbon nanofibers can not only address the problem of poor electrical conductivity of PBA derivatives but also provide confinement effect, which could reduce PBA aggregation and collapse. Furthermore, the coupling effect of porous nitrogen‐doped electrospun carbon nanofibers and PBA‐derived bimetallic phosphide nanoparticles facilitates sufficient exposure of active species, expedites electron transfer, accelerates reaction kinetics, and improves durability. [ABSTRACT FROM AUTHOR]

The discovery of a photomagnetic effect in a CoFe Prussian blue analog (PBA) has triggered a growing interest for photo‐switchable bimetallic cyanide‐bridged systems. Nevertheless, in between cyanide‐bridged extended coordination polymers and discrete molecules, the photo‐switching phenomena are much less well known in nano‐sized materials. A photo‐induced transformation, specific to the nanometric size, is evidenced by magnetometry and by X‐ray absorption spectroscopy at the Co and Fe K‐edges in an alkali cation free Prussian blue analog. The nanoparticles before irradiation can be described as having a core‐shell structure, the core being made of the well‐known fcc‐CoII(HS)FeIII structure of CoFe PBAs while the shell contains CoII ions in octahedral geometry and significantly distorted Fe(CN)6 entities. Irradiation induces a change of the local structures around the transition metal ions, which remain in the same oxidation state, with different behaviors of the Co and Fe sub‐lattices. [ABSTRACT FROM AUTHOR]

Overexpression of classically activated macrophages (M1) subtypes and assessed reactive oxygen species (ROS) levels are often observed in patients with ulcerative colitis. At present, the treatment system of these two problems has yet to be established. Here, the chemotherapy drug curcumin (CCM) is decorated with Prussian blue analogs in a straightforward and cost‐saving manner. Modified CCM can be released in inflammatory tissue (acidic environment), eventually causing M1 macrophages to transform into M2 macrophages and inhibiting pro‐inflammatory factors. Co(III) and Fe(II) have abundant valence variations, and the lower REDOX potential in CCM‐CoFe PBA enables ROS clearance through multi‐nanomase activity. In addition, CCM‐CoFe PBA effectively alleviated the symptoms of UC mice induced by DSS and inhibited the progression of the disease. Therefore, the present material may be used as a new therapeutic agent for UC. [ABSTRACT FROM AUTHOR]

A series of Prussian blue analogs (PBAs) having a range of crystal structures and compositions was investigated as heterogeneous catalysts for the fixation of carbon dioxide (CO2) to glycidol. The morphology of PBAs was modified, as confirmed by structural characterization, by varying the precipitation method. Of the prepared catalysts, the cubic Zn(II)-Co(III) PBA exhibited the highest catalytic activity (turn-over frequency up to 763 h−1), selectivity (up to 94%), and recyclability for the cycloaddition of CO2 to glycidol. In addition, branched polycarbonate polyols having tunable branching degree (0.15–0.61) and linear polycarbonates of relatively high carbonate content (up to 64.2%) were produced via ring-opening (multibranching) copolymerization of CO2 and various epoxides using a highly amorphous Zn(II)-Co(III) double metal cyanide catalyst. Mechanistic pathways have been proposed by combining experimental results with computational studies.

[Display omitted] Structure design and assembly control are the two key factors in designing new microwave absorbing materials and improving their electromagnetic wave absorption (EMWA) performance; however, balancing the coordination between these factors remains a great challenge. In this manuscript, a coprecipitation method and an in-situ polymerization method were used to construct nitrogen-carbon-doped popcorn-like porous nanocomposites (NiCoFe/N C). The metallic particles were encapsulated in approximately 10 layers of graphite carbon shells, and a NiCoFe/N C core–shell structure was formed. The EMWA properties of the NiCoFe/N C composites were adjusted by varying the divinylbenzene (DVB) to acrylonitrile (AN) content. The optimized NiCoFe/N C composite showed a minimum reflection loss of −57.5 dB and a maximum effective absorption bandwidth (EAB) of 5.44 GHz. The excellent EMWA properties of the NiCoFe/N C composites can be attributed to the synergistic effect among the core–shell structure, popcorn-like structure, magnetic metal, carbon and nitrogen. This effect leads to enhanced impedance matching, interface polarization, dipole polarization, multiple reflection and scattering in the composites. In this paper, an effective strategy for the preparation of high-performance magnetic/dielectric composites is provided by carefully designing a new microstructure. [ABSTRACT FROM AUTHOR]

Rechargeable lithium-ion batteries (LIBs) are known to be practical and cost-effective devices for storing electric energy. LIBs have a low energy density, which calls for the development of new anode materials. The Prussian blue analog (PBA) is identified as being a candidate electrode material due to its facile synthesis, open framework structures, high specific surface areas, tunable composition, designable topologies and rich redox couples. However, its poor electrical conductivity and mechanical properties are the main factors limiting its use. The present study loaded PBA (Co3[Fe(CN)6]·10H2O) on graphene oxide (Co-Fe-PBA@rGO) and then conducted calcination at 300 °C under the protection of nitrogen, which reduced the crystal water and provided more ion diffusion pathways. As a result, Co-Fe-PBA@rGO showed excellent performance when utilized as an anode in LIBs, and its specific capacities were 546.3 and 333.2 mAh g−1 at 0.1 and 1.0 A g−1, respectively. In addition, the electrode also showed excellent performance in the long-term cycle, and its capacity reached up to 909.7 mAh g−1 at 0.1 A g−1 following 100 cycles. [ABSTRACT FROM AUTHOR]

The construction of highly active and durable non‐noble‐metal electrocatalysts for the oxygen evolution reaction (OER) is an ongoing challenge. Here, we report the development of a hybrid nanostructure of PBA cubes wrapped with mixed W‐Co oxysulfides in a hair‐like structure through sulfurization of polyoxometalate (CoIIIW12 POM) as a bimetallic precursor. These unique heterostructures of PBA@Co−W−O−S grafted on carbon cloth afford abundant active sites and improved charge transfer kinetics that synergistically enhance the OER activity (overpotential of 250 mV at 10 mA cm−2). The synthetic approach used in this report can be extended for developing inexpensive, durable and efficient catalysts with diverse structures. [ABSTRACT FROM AUTHOR]

Developing facile methods for the synthesis of active and stable electrocatalysts is vitally important to realize overall water splitting. Here, we demonstrate a practical method to obtain FeNiOOH nanosheets on nickel foam (NF) as bifunctional electrocatalyst by growing a FeCo Prussian blue analog with further in situ oxidation under ambient conditions. The binder-free, self-standing FeNiOOH/NF electrode with hierarchical nanostructures requires low overpotentials of 260 mV and 240 mV at a current density of 50 mA cm−2 for oxygen evolution reaction and hydrogen evolution reaction, respectively, in 1.0 M KOH solution. Therefore, an alkaline water electrolyzer constructed by bifunctional FeNiOOH/NF electrode as both anode and cathode delivers 50 mA cm−2 under a cell voltage of 1.74 V with remarkable stability, which outperforms the IrO2-Pt/C-based electrolyzer. The excellent performance could be ascribed to the superior FeNiOOH intrinsic activity and the hierarchical structure. This work provides a cost-efficient surface engineering method to obtain binder-free, self-standing bifunctional electrocatalyst on commercial NF, which could be further extended to other energy and environment applications.

This study addresses the urgent need to focus on the nitrite reduction reaction (NO 2 - RR) to ammonia (NH 3 ). A ternary-metal Prussian blue analogue (CoCuFe-PBA) was utilized as the template material, leveraging its tunable electronic properties to synthesize CoCuFe oxide (CoCuFe-O) through controlled calcination. Subsequently, a CoCuFe alloy (CoCuFe-A) was obtained via pulsed laser irradiation in liquids. The electrochemical properties of CoCuFe-O, derived from the PBA crystal structure, demonstrated a high yield of NH 4 + at a rate of 555.84 μmol h -1 cm -2 , with the highest Faradaic efficiency of 91.8% and a selectivity of 97.3% during a 1-h NO 2 - RR under an optimized potential of -1.0 V vs. Ag/AgCl. In situ Raman spectroscopy revealed the collaborative role of redox pairs (Co 3+ /Co 2+ and Fe 3+ /Fe 2+ ) as proton (H + ) suppliers, with Cu centers serving as NO 2 - binders, thereby enhancing the reaction rate. Additionally, theoretical studies confirmed that Fe and Co atoms are more reactive than Cu toward intermediates playing crucial roles in hydrogenation, while Cu primarily activates NO owing to hydrogenation by the Fe and Co atoms and a high kinetic barrier in H 2 O* adsorption. This comprehensive investigation provides valuable insights into the electrochemical NO 2 - RR, establishing a foundation for efficient and sustainable NH 3 synthesis strategies.

[Display omitted] P-nitrophenol (PNP), a widely used compound, is harmful to the environment and human health. In this study, four iron-based Prussian blue analogs (PBAs) were prepared by coprecipitation (Co-Fe PBA, Mn-Fe PBA, Cu-Fe PBA and Fe-Fe PBA). The Co-Fe PBA exhibited high peroxymonosulfate (PMS) activation performance for PNP degradation, removing over 90% of PNP in 60 min at an optimal pH of 7, temperature at 30 ℃, initial concentration of 20 mg/L, PBA dose of 0.2 g/L and PMS dose of 1 g/L. The physicochemical properties of the Co-Fe PBA were investigated by various characterization methods. The catalytic activity of PBA and the influence of various process parameters and water quality on the catalytic reaction were investigated to elucidate the mechanism of p-nitrophenol degradation by PBA-activated persulfate. Moreover, the mechanism of accelerated degradation of PNP under HCO 3 – conditions and the role of major reactive oxides were determined by EPR measurement methods and free radical trapping experiments. HCO 3 – was found to directly activate PMS to produce reactive oxygen species, and 1O 2 , ∙OH and SO 4 ∙- were all greatly increased. This work presents a promising green heterogeneous catalyst for the degradation of emerging contaminants (ECs) in real wastewater with natural organic matter and coexisting anions by PMS activation. [ABSTRACT FROM AUTHOR]

Abstract: Aqueous rechargeable zinc‐based batteries with the advantages of sustainability, safety, and low cost, are suitable for large‐scale electrochemical energy storage applications. In this work, aqueous zinc‐based batteries with low defect Berlin green (FeHCF) cathode, a hybrid zinc triflate and potassium triflate electrolyte, and zinc anodes are developed. In the hybrid electrolyte, the K+ ions with the weak solvation effect and small electrostatic interaction are the dominant intercalation species in the FeHCF, resulting in the fast charge transfer process and rapid diffusion kinetics. The Zn2+ ions stay at the surface rather than penetrate into the bulk phase. Thus, the hybrid batteries deliver a high specific capacity of 169.2 mAh g−1 at 100 mA g−1, excellent rate performance with 45.7 mAh g−1 at 6 A g−1, and good long‐term cyclability with a capacity retention of 57 % over 1000 cycles at 1 A g−1. The results suggest using aqueous K/Zn hybrid electrolytes can improve the electrochemical performance of FeHCF. [ABSTRACT FROM AUTHOR]

Electrochemical proton storage provides high energy, fast kinetics, safety, and environmental friendliness for grid‐scale energy storage. However, the development of pseudocapacitive proton supercapacitors with fast chargeability and high stability is still challenging because of the unclear electrochemical reaction mechanism and unsuitable construction strategy. Here it is shown that a multi‐metallic Prussian blue analog—Cu0.82Co0.18HCF, which possesses enhanced electronic structure and ion transport path—can intercalate/de‐intercalate large amounts of proton at high rates. Ion‐induced transformation of magnetism, fast solid‐state proton transport, and reversible insertion/de‐insertion of protons lead to extremely excellent rate capacities and cycling stability for proton storage. An asymmetric pseudocapacitive proton supercapacitor (Cu0.82Co0.18HCF//WO3·nH2O) is fabricated with a voltage window of 1.7 V, delivering a maximum energy density of 35 Wh kg−1 and an energy density of 22 Wh kg−1 at a high power density of 26 kW kg−1. Combining systematical material design and mechanism study, this work not only broadens the preparation of electrode materials but also brings light to the construction of high‐performance devices for efficient proton storage. [ABSTRACT FROM AUTHOR]

The peroxynitrite photocatalytic degradation system was considered a green, convenient, and efficient water treatment process, but not satisfying against some antibiotics, e.g. sulfonamides (SAs). To improve the photocatalytic degradation efficiency of SAs, sulfur was introduced to a magnetic Fe-MOF (Fe-metal organic framework) Prussian blue analog to achieve a heteroatomic material CuFeO@S, which was applied in heterogeneous visible light photo-assisted catalytic process with persulfate (PS) as an oxidant. The characterization results of CuFeO@S by XRD and XPS confirmed the presence of Fe 3 O 4 (for magnetic separation), Cu+ (for activation of PS) and S2− (for narrowing the energy band and prolonging the lifetime of photo-generated electronics). Through systematic optimization of reaction conditions in CuFeO@S + PS + hv system, efficient degradation of four tested SAs was achieved in 30 min (removal rate of 97–100% for the tested 4 SAs). Moreover, the material could be magnetically recycled and reused for over 7 cycles with a removal rate of >90% for sulfamerazine. Furthermore, the removal rate of sulfamerazine in pond water reached 99% at a mineralization rate of about 34% (decrease in total organic matter), demonstrating its potential in the treatment of antibiotic-containing wastewater. [Display omitted] • Sulfur was incorporated into a magnetic Prussian blue analog to improve the photo-catalytic efficiency. •Removal rates of over 99% against sulfonamides were achieved in a photo-assisted persulfate oxidation system. •The residual material after the reaction could be recycled for reuse with a magnet. [ABSTRACT FROM AUTHOR]

Abstract Janus structures that include different functional compartments have attracted significant attention due to their specific properties in a diverse range of applications. However, it remains challenge to develop an effective strategy for achieving strong interfacial interaction. Herein, a Janus nanoreactor consisting of TiO2 2D nanocrystals integrated with Prussian blue analog (PBA) single crystals is proposed and synthesized by mimicking the planting process. In situ etching of PBA particles induces nucleation and growth of TiO2 nanoflakes onto the concave surface of PBA particles, and thus enhances the interlayer interaction. The anisotropic PBA–TiO2 Janus nanoreactor demonstrates enhanced photocatalytic activities for both water reduction and oxidation reactions compared with TiO2 and PBA alone. As far as it is known, this is the first PBA‐based composite that serves as a bifunctional photocatalyst for solar water splitting. The interfacial structure between two materials is vital for charge separation and transfer based on the spectroscopic studies. These results shed light on the elaborate construction of Janus nanoreactor, highlighting the important role of interfacial design at the microscale level.

Janus structures that include different functional compartments have attracted significant attention due to their specific properties in a diverse range of applications. However, it remains challenge to develop an effective strategy for achieving strong interfacial interaction. Herein, a Janus nanoreactor consisting of TiO2 2D nanocrystals integrated with Prussian blue analog (PBA) single crystals is proposed and synthesized by mimicking the planting process. In situ etching of PBA particles induces nucleation and growth of TiO2 nanoflakes onto the concave surface of PBA particles, and thus enhances the interlayer interaction. The anisotropic PBA–TiO2 Janus nanoreactor demonstrates enhanced photocatalytic activities for both water reduction and oxidation reactions compared with TiO2 and PBA alone. As far as it is known, this is the first PBA‐based composite that serves as a bifunctional photocatalyst for solar water splitting. The interfacial structure between two materials is vital for charge separation and transfer based on the spectroscopic studies. These results shed light on the elaborate construction of Janus nanoreactor, highlighting the important role of interfacial design at the microscale level. [ABSTRACT FROM AUTHOR]

Aqueous potassium-ion batteries (AKIBs) are considered promising electrochemical energy storage systems owing to their high safety and cost-effectiveness. However, the structural degradation resulting from the repeated accommodation of large K-ions and the dissolution of active electrode materials in highly dielectric aqueous electrolytes often lead to unsatisfactory electrochemical performance. This study introduces a high-entropy Prussian blue analog (HEPBA) cathode material for AKIBs, demonstrating significantly enhanced structural stability and reduced dissolution. The HEPBA exhibits a highly reversible specific capacity of 102.4 mAh g -1 , with 84.4% capacity retention after undergoing 3448 cycles over a duration of 270 days. Mechanistic insights derived from comprehensive experimental investigations, supported by theoretical calculations, reveal that the HEPBA features a robust structure resistant to dissolution, a solid-solution reaction pathway with negligible volume variation during charge-discharge, and efficient ion transport kinetics characterized by a reduced band gap and a low energy barrier. This study represents a measurable step forward in the development of long-lasting electrode materials for aqueous AKIBs., (© 2023 Wiley‐VCH GmbH.)

A battery management system (BMS) plays a pivotal role in providing optimal performance of lithium-ion batteries (LIBs). However, the eventual malfunction of the BMS may lead to safety hazards or reduce the remaining useful life of LIBs. Manganese hexacyanoferrate (MnHCF) was employed as the positive electrode material in a Li-ion half-cell and subjected to five cycles at high current densities (10 A gMnHCF−1) and to discharge at 0.1 A gMnHCF−1, instead of classical charge/discharge cycling with initial positive polarization at 0.01 A gMnHCF−1, to simulate a current sensor malfunctioning and to evaluate the electrochemical and structural effects on MnHCF. The operando set of spectra at the Mn and Fe K-edges was further analyzed through multivariate curve resolution analysis with an alternating least squares algorithm (MCR–ALS) and extended X-ray absorption fine structure (EXAFS) spectroscopy to investigate the structural modifications arising during cycling after the applied electrochemical protocol. The coulombic efficiency in the first cycle was dramatically affected; however, the local structural environment around each photo absorber recovered during charging. The identification of an additional spectral contribution in the electrochemical process was achieved through MCR-ALS analysis, and the Mn-local asymmetry was thoroughly explored via EXAFS analysis. [ABSTRACT FROM AUTHOR]

Lithium‐ion, sodium‐ion, and potassium‐ion batteries have captured tremendous attention in power supplies for various electric vehicles and portable electronic devices. However, their practical applications are severely limited by factors such as poor rate capability, fast capacity decay, sluggish charge storage dynamics, and low reversibility. Herein, hetero‐structured bimetallic sulfide (NiS/FeS) encapsulated in N‐doped porous carbon cubes interconnected with CNTs (Ni‐Fe‐S‐CNT) are prepared through a convenient co‐precipitation and post‐heat treatment sulfurization technique of the corresponding Prussian‐blue analogue nanocage precursor. This special 3D hierarchical structure can offer a stable interconnect and conductive network and shorten the diffusion path of ions, thereby greatly enhancing the mobility efficiency of alkali (Li, Na, K) ions in electrode materials. The Ni‐Fe‐S‐CNT nanocomposite maintains a charge capacity of 1535 mAh g−1 at 0.2 A g−1 for lithium ion batteries, 431 mAh g−1 at 0.1 A g−1 for sodium ion batteries, and 181 mAh g−1 at 0.1 A g−1 for potassium‐ion batteries, respectively. The high performance is mainly attributed to the 3D hierarchically high‐conductivity network architecture, in which the hetero‐structured FeS/NiS nanocubes provide fast Li+/Na+/K+ insertion/extraction and reduced ion diffusion paths, and the distinctive 3D networks maintain the electrical contact and guarantee the structural integrity. [ABSTRACT FROM AUTHOR]

In response to the energy crisis, molybdenum-based catalyst has been proposed as a high-performance electrocatalytic material due to its low price and excellent HER performance. However, in contrast with its excellent HER performance, its poor OER performance often limits practical application as a high-performance overall water splitting catalyst. In this study, Prussian blue analogue (PBA) is grown in-situ on molybdenum-based nanosheet spheres by a simple and ingenious method and then subjected to phosphorization. The resulting composite catalyst exhibits highly efficient overall water splitting performance, overpotentials at current densities of 10 mA cm−2 and 100 mA cm−2 for the HER and OER are −61 mV and 268 mV, respectively. Moreover, an alkaline electrolyzer makes up by the catalyst both as positive and negative can reach a cell voltage 1.494 V at 10 mA cm−2 for the overall water splitting. This method has provided a new strategy to effective combine PBA and molybdenum-based catalyst. Image 1 • Prussian Blue Analogue (PBA) in-situ grow on Molybdenum-based nanosheet spheres. • OER performance of catalysts greatly improved by PBA anchoring. • It provided a strategy to combine the PBA and matrix effectively. [ABSTRACT FROM AUTHOR]

Recently, Prussian blue analogs (PBAs) have attracted much attention due to their transformation into dielectric/magnetic coupled composites after pyrolysis at high temperatures and their ability to maintain their basic morphology. However, designing efficient microwave-absorbing materials using PBAs is still a challenge. In this work, Co–Fe PBA was prepared by wet chemical method and graphene aerogel-encapsulated double carbon-shell CoFe@C@C nanocubes (CFCCG) were prepared by stirred self-polymerization and hydrothermal method, and heat-treated at different temperatures to obtain composites consisting of core-shell-structured PBA-derived particles encapsulated in a double layer of graphene and polydopamine (PDA). The addition of graphene not only reduces the density of the derived material but also effectively disperses the CoFe@C@C nanocubes to prevent the generated highly conductive carbon layer from adhering to improve the impedance matching, as well as introduces a large number of heterogeneous interfaces to improve the loss capability. Thanks to which the CFCCG7 composites have a reflection loss of −66.33 dB and an effective microwave absorption frequency covering the entire Ku-band. This work provides a new approach for rational design of multilayer carbon structure-coated PBA-based microwave absorbing materials. [Display omitted] • Co–Fe PBAs can optimize impedance matching to enhance absorption of microwave. • Graphene can uniformly encapsulate CoFe@C@C nanospheres to enhance dielectric loss. • CFCCG7 exhibits excellent electromagnetic wave absorption performance in Ku band. [ABSTRACT FROM AUTHOR]

Recently, considerable research has been conducted on Prussian blue analogues (PBAs), a type of metal-organic framework (MOF) material, as novel electrocatalysts for oxygen evolution reactions (OERs) and urea oxidation reactions (UORs). In the present work, considering Co–Ni hexacyanoferrate (Co _x Ni _1−x HCF) as a PBA, Co _x Ni _1−x HCF nanocuboids with different Co and Ni compositions were synthesized on Ni foam (NF) by hydrothermal synthesis. Further, their application toward OER and UOR catalytic activity was studied. The synthesized Co _x Ni _1−x HCF:NF composites with high catalytic activity and conductivity exhibited superior catalytic performance for the OERs and UORs. The Co _x Ni _1−x HCF:NF composite electrodes exhibited a lower overpotential ( η ) of 334 mV with a lower Tafel slope of 72 mV dec ^−1 for the OER catalytic activity and a lower potential of 1.38 V with a lower Tafel slope of 50 mV dec ^−1 for the UOR catalytic activity. It was observed that low charge transfer resistance, high electrochemically active surface area, and availability of Co ^3+ ions are major factors contributing to the OER activity. The presence of oxidative Ni ^2+ species contributed significantly to the UOR activity. Overall, the present study elucidates the binder-free Co _x Ni _1−x HCF:NF electrodes as stable and high-performance OER and UOR catalysts and provides pathways for designing advanced PBA catalysts.

The sluggish kinetics of oxygen evolution reaction (OER) on anode hinders the efficiency of electrochemical water splitting. Electrocatalysts for OER based on non-precious transition metals are highly desirable. Herein, iron and nickel mixed oxides with surface oxygen vacancies were fabricated using NiIIFeII-Prussian blue analog as the precursors by a facile two-step thermal-assisted method. The precursor compositions and calcination temperatures exert great impact on the structure and morphology of the derivatives, as well as the electrocatalytic performances for OER. Both the higher content of Ni ions during the synthesis of precursors and lower calcination temperature favor the electrocatalytic performance of the corresponding derivatives. The porous metal oxides consisting of nickel oxide and nickel ferrite exhibited the remarkable electrocatalytic property toward OER in an alkaline solution, which can be attributed to the nanosized and porous structure, the co-existence of spinel NiFe2O4 and cubic NiO, the high content of surface oxygen vacancies, and the low charge transfer resistance. This study will provide new inspiration for the facile design of low-cost active catalysts for OER in the future.

Herein, a facile and highly effective nonenzymatic electrochemical sensing system is designed for the detection of the antibacterial drug nitrofurantoin (NFT). This electrocatalyst is a combination of a trimetallic Prussian blue analogue and conductive polyaniline coated onto a three-dimensional porous nickel foam substrate. A comprehensive set of physicochemical analyses have verified the successful synthesis. The fabricated electrochemical sensor exhibits an impressively low limit of detection (0.096 nM) and quantification (0.338 nM, S/N = 3.3), coupled with a wide linear range spanning from 0.1 nM to 5 mM and a sensitivity of 13.9 μA nM -1 cm -2 . This excellent performance is attributed to the collaborative effects of conducting properties of polyaniline (PANI) and the remarkable redox behavior of the Prussian blue analogue (PBA). When both are integrated into the nickel foam, they create a significantly enlarged surface area with numerous catalytic active sites, enhancing the sensor's efficiency. The sensor demonstrates a high degree of specificity for NFT, while effectively minimizing responses to potential interferences such as flutamide, ascorbic acid, glucose, dopamine, uric acid, and nitrophenol, even when present in 2-3-fold higher concentrations. Moreover, to validate its practical utility, the sensor underwent real sample analysis using synthetic urine, achieving outstanding recovery rates of 118 and 101%.

Metal hexacyanoferrates are recognized as superior cathode materials for zinc and zinc hybrid batteries, particularly the Prussian blue analog (PBA). However, PBA development is hindered by several limitations, including small capacities (<70 mAh g -1 ) and short lifespans (<1000 cycles). These limitations generally arise due to incomplete activation of redox sites and structure collapse during intercalation/deintercalation of metal ions in PBAs. According to this study, the adoption of a hydroxyl-rich (OH-rich) hydrogel electrolyte with extended electrochemical stability windows (ESWs) can effectively activate the redox site of low-spin Fe of the K x Fe y Mn 1-y [Fe(CN) 6 ] w ·zH 2 O (KFeMnHCF) cathode while tuning its structure. Additionally, the strong adhesion of the hydrogel electrolyte inhibits KFeMnHCF particles from falling off the cathode and dissolving. The easy desolvation of metal ions in the developed OH-rich hydrogel electrolytes can lead to a fast and reversible intercalation/deintercalation of metal ions in the PBA cathode. As a result, the Zn||KFeMnHCF hybrid batteries achieve the unprecedented characteristics of 14 500 cycles, a 1.7 V discharge plateau, and a 100 mAh g -1 discharge capacity. The results of this study provide a new understanding of the development of zinc hybrid batteries with PBA cathode materials and present a promising new electrolyte material for this application., (© 2023 Wiley‐VCH GmbH.)

A fluorometric assay for histidine (His) is described. It is based on the inhibitory effect of His on nanocubes consisting of cobalt-containing Prussian Blue analog (CoFe NCbs), which have a strong oxidation effect on thiamine (THI) in the presence of NaOH. THI is nonfluorescent but the oxidized form (thiochrome; ThC) has a strong blue fluorescence, with excitation/emission maxima at 370/445 nm. His inhibits the oxidation effect of the CoFe NCbs due to the strong interaction between its imidazole side chain and the amino groups of the CoFe NCbs. This method is fast and has good sensitivity and selectivity. The lower detection limit is 14.3 nM of His, the linear range extends from 0.05 to 2.5 μM, and the relative standard deviation is calculated to be 1.5%. The method was successfully employed to quantify His in spiked serum samples. [ABSTRACT FROM AUTHOR]

Electrocatalytic reduction of nitrate to ammonia (ERNA) not only produces valuable ammonia, but also solves the problem of NO 3 - pollution in wastewater. Here, Co-Co PBA (Prussian blue analog) microcubes were applied as templates to synthesize Co 3 O 4 catalyst. The transition metal Cu-doped Co 3 O 4 catalyst effectively improved the performance of electrocatalytic nitrate reduction for ammonia synthesis. In 0.1 M KOH including 0.1 M NO 3 - electrolyte, 30Cu-Co 3 O 4 catalyst (the doping amount was 30 mg) shows high Faraday efficiency (FE) of 92.4 % and large NH 3 yield rate of 0.584 mmol h-1 mg cat −1 at − 0.4 V Vs. RHE (Reversible hydrogen electrode), which benefiting from framework structure of PBA, abundant exposed active sites and beefed-up interfacial and electronic interactions between metals and metal oxides. Meanwhile, 30Cu-Co 3 O 4 catalyst has greater stability in the longtime electrolysis process, NH 3 (ammonia) originates from nitrate electroreduction was confirmed by 15N isotope labeling experiments. In addition, 30Cu-Co 3 O 4 catalyst has certain application potential in the synthesis of ammonia from nitrate-containing industrial wastewater. [Display omitted] [ABSTRACT FROM AUTHOR]

A battery management system (BMS) plays a pivotal role in providing optimal performance of lithium-ion batteries (LIBs). However, the eventual malfunction of the BMS may lead to safety hazards or reduce the remaining useful life of LIBs. Manganese hexacyanoferrate (MnHCF) was employed as the positive electrode material in a Li-ion half-cell and subjected to five cycles at high current densities (10 A gMnHCF−1) and to discharge at 0.1 A gMnHCF−1, instead of classical charge/discharge cycling with initial positive polarization at 0.01 A gMnHCF−1, to simulate a current sensor malfunctioning and to evaluate the electrochemical and structural effects on MnHCF. The operando set of spectra at the Mn and Fe K-edges was further analyzed through multivariate curve resolution analysis with an alternating least squares algorithm (MCR–ALS) and extended X-ray absorption fine structure (EXAFS) spectroscopy to investigate the structural modifications arising during cycling after the applied electrochemical protocol. The coulombic efficiency in the first cycle was dramatically affected; however, the local structural environment around each photo absorber recovered during charging. The identification of an additional spectral contribution in the electrochemical process was achieved through MCR-ALS analysis, and the Mn-local asymmetry was thoroughly explored via EXAFS analysis.

Electrochemical water splitting in alkaline media plays an important role in mass production of hydrogen. Ruthenium (Ru), as the cheapest member of platinum-group metals, has attracted much attention, and the incorporation of trace amount of Ru with cobalt phosphide could significantly improve the hydrogen evolution reaction (HER) catalytic activity. In this work, ruthenium-incorporated cobalt phosphide nanocubes are synthesized via a reaction between Co–Co Prussian blue analog (Co-PBA) and ruthenium chloride (RuCl3) followed by the phosphidation. The sample with a Ru content of ~2.04 wt.% exhibits the best HER catalytic activity with a low overpotential of 51 and 155 mV, to achieve the current densities of −10 and −100 mA cm−2, respectively, and the Tafel slope of 53.8 mV dec−1, which is comparable to the commercial Pt/C. This study provides a new perspective to the design and construction of high performance electrocatalysts for HER and other catalytic applications in a relatively low price.