Boosting Electrochemical Water Oxidation with Metal Hydroxide Carbonate Templated Prussian Blue Analogues

The development of efficient and stable catalyst systems with low‐cost, abundant, and non‐toxic materials is the primary demand for electrochemical water oxidation. A unique method is reported for the syntheses of metal hydroxide carbonate templated Prussian blue analogues (PBAs) on carbon cloth and their outstanding water oxidation activities in alkaline medium. The best water oxidation activity is obtained with cobalt hydroxide carbonate templated t‐Co^II‐Co^III with an overpotential as low as 240 mV to reach a current density of 10 mA cm^?2. It produces constant current over 50 h in chronoamperometric measurements. Moreover, the catalysts outperform the activities of the PBAs prepared without any template and even the noble metal catalyst RuO₂. Spectroscopic and microscopic studies show that the PBAs are transformed into layered hydroxide–oxyhydroxide structures during electrochemical process and provide the active sites for the water oxidation.     

BiVO4-MCM-41复合催化剂的制备及其对亚甲基蓝降解的光催化活性

将单斜白钨矿结构的BiVO4固载于中孔MCM-41分子筛上,制备了BiVO4-MCM-41复合催化剂,并对催化剂进行了表征,考察了催化剂在光催化亚甲基蓝降解反应中的催化活性.结果表明,BiVO4首先在MCM-41分子筛上形成锆石结构或四面体白钨矿结构的结晶,通过水热处理之后转变为单斜结构的结晶.BiVO4-MCM-41催化剂不仅保持了BiVO4较高的光催化活性,而且提高了对亚甲基蓝的吸附性能,从而提高了对亚甲基蓝降解反应的光催化活性.     

Binder-Free Fabrication of Prussian Blue Analogues Based Electrocatalyst for Enhanced Electrocatalytic Water Oxidation

Developing a cost-effective, efficient, and stable oxygen evolution reaction (OER) catalyst is of great importance for sustainable energy conversion and storage. In this study, we report a facile one-step fabrication of cationic surfactant-assisted Prussian blue analogues (PBAs) M_x[Fe(CN)₅CH₃C₆H₄NH₂]∙yC₁₉H₃₄NBr abbreviated as SF[Fe-Tol-M] (where SF = N-tridecyl-3-methylpyridinium bromide and M = Mn, Co and Ni) as efficient heterogeneous OER electrocatalysts. The electrocatalysts have been characterized by Fourier transform infrared (FT-IR) spectroscopy, powder X-ray diffraction (PXRD), scanning electron microscopy (SEM) coupled with energy dispersive X-ray (EDX) analysis, and X-ray photoelectron spectroscopy (XPS). In the presence of cationic surfactant (SF), PBAs-based electrodes showed enhanced redox current, high surface area and robust stability compared to the recently reported PBAs. SF[Fe-Tol-Co] hybrid catalyst shows superior electrochemical OER activity with a much lower over-potential (610 mV) to attain the current density of 10 mA cm⁻² with the Tafel slope value of 103 mV·dec⁻¹ than that for SF[Fe-Tol-Ni] and SF[Fe-Tol-Mn]. Moreover, the electrochemical impedance spectroscopy (EIS) unveiled that SF[Fe-Tol-Co] exhibits smaller charge transfer resistance, which results in a faster kinetics towards OER. Furthermore, SF[Fe-Tol-Co] offered excellent stability for continues oxygen production over extended reaction time. This work provides a surface assisted facile electrode fabrication approach for developing binder-free OER electrocatalysts for efficient water oxidation.     

普鲁士蓝类分子磁体研究的新进展

在分子磁体的研制中,多氰金属盐是一类非常合适的分子前体。它有可能组装成高自旋基态、高居里温度或具有各向异性的分子基磁体。本文将介绍此类分子磁体的研究新成果及发展前景。     

How to Build Prussian Blue Based Water Oxidation Catalytic Assemblies: Common Trends and Strategies

Prussian blue (PB) and its analogues (PBAs) have at least a three-century-long history in coordination chemistry. Recently, cobalt-based PBAs have been acknowledged as efficient and robust water oxidation catalysts. Given the flexibility in their synthesis, the structure and morphology of cobalt-based PBAs have been modified for enhanced catalytic activity under electrochemical (EC), photocatalytic (PC), and photoelectrochemical (PEC) conditions. Here, in this review, the work on cobalt-based PBAs is presented in four sections: i) electrocatalytic water oxidation with bare PBAs, ii) photocatalytic processes in the presence of a photosensitizer (PS), iii) photoelectrochemical water oxidation by coupling PBAs to proper semiconductors (SCs), and iv) the utilization of PBA-PS assemblies coated on SCs for the dye-sensitized photoelectrochemical water oxidation. This review will guide readers through the structure and catalytic activity relationship in cobalt-based PBAs by describing the role of each structural component. Furthermore, this review aims to provide insight into common strategies to enhance the catalytic activity of PBAs.     

Building an Iron Chromophore Incorporating Prussian Blue Analogue for Photoelectrochemical Water Oxidation

The replacement of traditional ruthenium-based photosensitizers with low-cost and abundant iron analogs is a key step for the advancement of scalable and sustainable dye-sensitized water splitting cells. In this proof-of-concept study, a pyridinium ligand coordinated pentacyanoferrate(II) chromophore is used to construct a cyanide-based CoFe extended bulk framework, in which the iron photosensitizer units are connected to cobalt water oxidation catalytic sites through cyanide linkers. The iron-sensitized photoanode exhibits exceptional stability for at least 5 h at pH 7 and features its photosensitizing ability with an incident photon-to-current conversion capacity up to 500 nm with nanosecond scale excited state lifetime. Ultrafast transient absorption and computational studies reveal that iron and cobalt sites mutually support each other for charge separation via short bridging cyanide groups and for injection to the semiconductor in our proof-of-concept photoelectrochemical device. The reorganization of the excited states due to the mixing of electronic states of metal-based orbitals subsequently tailor the electron transfer cascade during the photoelectrochemical process. This breakthrough in chromophore-catalyst assemblies will spark interest in dye-sensitization with robust bulk systems for photoconversion applications.     

A Robust,Precious‐Metal‐Free Dye‐Sensitized Photoanode for Water Oxidation: A Nanosecond‐Long Excited‐State Lifetime through a Prussian Blue Analogue

Herein, we establish a simple synthetic strategy affording a heterogeneous, precious metal‐free, dye‐sensitized photoelectrode for water oxidation, which incorporates a Prussian blue (PB) structure for the sensitization of TiO₂ and water oxidation catalysis. Our approach involves the use of a Fe(CN)₅ bridging group not only as a cyanide precursor for the formation of a PB‐type structure but also as an electron shuttle between an organic chromophore and the catalytic center. The resulting hetero‐functional PB‐modified TiO₂ electrode demonstrates a low‐cost and easy‐to‐construct photoanode, which exhibits favorable electron transfers with a remarkable excited state lifetime on the order of nanoseconds and an extended light absorption capacity of up to 500 nm. Our approach paves the way for a new family of precious metal‐free robust dye‐sensitized photoelectrodes for water oxidation, in which a variety of common organic chromophores can be employed in conjunction with CoFe PB structures.     

Organic Redox Probes for the Key Oxidation States in Mixed Valence Ruthenium Oxide/Cyanometallate (Ruthenium Prussian Blue Analogue) Catalysts

The electrochemical redox behavior of the polynuclear mixed valence ruthenium oxide cyanometallate complexes (mvRuOx? MCN, M=Fe, Cr, Ni, Cu, Ru and Pt) have been systematically studied in this report by using three redox sensitive organic probes of glucose, ethanol and formaldehyde. The results were interpreted by the well‐established ruthenium oxide and Prussian blue chemistry. The mvRuOx? MCN, under the category of Ru‐based Prussian blue analogue, was found to possess superior electrocatalytic activity than either ruthenium oxide or Prussian blue in acidic mediums. The electrogenerated oxy/hydroxy‐Ru^VII state (at +1.1 V vs. Ag/AgCl) was unusually stabilized in the mvRuOx? MCN matrix without any disproportion reaction in acidic environments. In contrast to those of earlier studies, possible structure in terms of the ? Ru^III/II? NC? M? and ? Ru^III/II? O? Ru^VII/VI? sites was proposed here. Enzyme‐less analytical detection of glucose in acidic conditions was first time demonstrated with sensitivity comparable to that of ruthenium oxide‐based electrodes in alkaline solutions.     

Enhanced Electrochemical Water Oxidation Activity by Structural Engineered Prussian Blue Analogue/rGO Heterostructure

Prussian blue analogue (PBA), with a three-dimensional open skeleton and abundant unsaturated surface coordination atoms, attracts extensive research interest in electrochemical energy-related fields due to facile preparation, low cost, and adjustable components. However, it remains a challenge to directly employ PBA as an electrocatalyst for water splitting owing to their poor charge transport ability and electrochemical stability. Herein, the PBA/rGO heterostructure is constructed based on structural engineering. Graphene not only improves the charge transfer efficiency of the compound material but also provides confined growth sites for PBA. Furthermore, the charge transfer interaction between the heterostructure interfaces facilitates the electrocatalytic oxygen evolution reaction of the composite, which is confirmed by the results of the electrochemical measurements. The overpotential of the PBA/rGO material is only 331.5 mV at a current density of 30 mA cm⁻² in 1.0 M KOH electrolyte with a small Tafel slope of 57.9 mV dec⁻¹, and the compound material exhibits high durability lasting for 40 h.     

Co-Fe普鲁士蓝类配合物纳米颗粒的微乳液法制备与表征

Highly oriented cubic, hollow cubic and spherical nanoparticles of cobalt-iron Prussian blue analogues were synthesized in poly oxyethylene tertoctylphenyl ether (TritonX-100)/n-hexanol/cyclohexane microemulsion. The effects of the water-to-surfactant molar ratio (w), the reactant concentration and the reaction temperature on the morphology of cobalt-iron Prussian blue analogues were studied. The samples were characterized by transmission electron microscopy (TEM), field emission scan electron microscopy (FE-SEM), energy-dispersive X-ray spectroscopy (EDS), X-ray diffraction (XRD) and infrared spectroscopy (IR).     

中空和基底支撑型普鲁士蓝及其类似物和衍生物用于绿色水分解

随着世界对能源需求的日益增长,为减少对化石燃料的严重依赖同时实现碳达峰和碳中和,迫切需要探索发现新型能源和能源载体.与其他燃料相比,氢气具有零碳排放、能量密度高、清洁可再生和来源广泛等特点,因此被认为是理想的能源载体.目前,工业制氢主要有三种策略,分别是甲烷水蒸气重整(SMR)、煤炭水蒸气(CG)和水电解(WE).其中SMR和CG制氢占95％,而WE制氢仅占4％.虽然前二者制氢成本较低,但会伴生大量的二氧化碳,相比之下,WE制氢纯度高,绿色无污染,更加符合目前的环保理念.目前WE制氢的核心问题之一就是设计和合成高效、廉价的电催化剂.具有类贵金属催化性能的过渡金属基电催化剂(例如钴基、镍基和铁基材料)已经引起了学术界的广泛关注.配位聚合物(CP)由于其具有固有的金属元素、内部结构化学可调、比表面积大和结构有序等优点,在吸附、催化和储能等领域得到了广泛的应用.作为18世纪发现的第一个人工配位聚合物,普鲁士蓝(PB)及其类似物(PBAs)和具有可调金属中心的衍生物作为一种新型的光催化剂或电催化剂受到了广泛的关注.本综述详细介绍了以普鲁士蓝及其类似物和衍生物构筑的中空结构和基底支撑型纳米材料在绿色水分解方面的基础研究及应用进展.本文首先简单介绍了普鲁士蓝及其类似物的基本结构组成,并对其优缺点进行了总结;随后,针对普鲁士蓝及其类似物的中空结构的合成策略和形成机理展开了详细地阐述,包括单层中空纳米盒、开孔式纳米笼以及复杂中空结构等;此外,针对基底支撑型普鲁士蓝及其类似物结构合成机理也进行了详细地解释,包括泡沫镍网、铁网、碳布、铜网等基底,并与中空结构进行了对比总结,该类负载型结构可以充分发挥活性位的利用效率,达到更好的催化性能.此外,结合最新的研究进展,介绍了普鲁士蓝及其类似物和衍生物(氢氧化物、磷化物、硫族化合物和碳化物)在水裂解中的应用,包括电解水和光催化制氢,并对电解水的机理进行了总结.最后,本文总结了该领域目前存在的局限性和面临的紧迫挑战.希望本综述能够激发更多研究者投身于复杂结构普鲁士蓝及其类似物和衍生物的高效绿色水裂解方面的研究工作.     

Progress of Prussian Blue and Its Analogues as Cathode Materials for Potassium Ion Batteries

Environmental pollution and the energy crisis have promoted the development of clean energy as well as new-generation energy storage systems. Potassium ion batteries (PIBs) have emerged as a possible alternative to lithium-ion batteries due to their abundant reserves, low cost, and impressive electrochemical performance. However, the search for suitable cathode materials has become particularly crucial. Recently, Prussian blue (PB) has been investigated as a potential cathode material for PIBs, which has an open three-dimensional framework to accommodate a large volume of potassium ions and adjustable composition for different applications. In this review, Prussian blue and its analogues (PBAs) and their application in PIBs were summarized detailly. We presented the composition, structure, potassium ion storage mechanism, preparation process of PBAs, and then focus on the performance optimization methods of the PBAs, including transition metal doping and conductive material adding into PBAs. Finally, the challenges as well as the outlook on the future development of PBAs were proposed for further application in this battery system.     

基于溶胶-凝胶普鲁士蓝膜修饰玻碳电极电催化氧化测定水果中抗坏血酸

制备了一种溶胶-凝胶普鲁士蓝膜修饰玻碳电极,研究了抗坏血酸在该电极上的电催化氧化作用,建立了测定抗坏血酸的方法。在磷酸缓冲溶液(pH 5.0)中,在2.5×10-5-3.2×10-3mol.L-1范围内,抗坏血酸的浓度与氧化峰电流呈线性关系,相关系数为0.999 5,检出限为7×10-6mol.L-1。该修饰电极具有制备简单、灵敏度高、响应速度快、稳定性和重现性好等特点。方法已用于水果中抗坏血酸的测定,所得结果与药典法测得结果一致。     

普鲁士蓝修饰生物传感器的研究进展

文中叙述了普鲁士蓝(PB)结构特征和电化学特性,PB在过氧化氢传感器中的应用。综述了PB葡萄糖传感器及其他基于PB的生物氧化酶传感器的研究进展。引用文献52篇。     

Enhancement of the Electrochemical Performance of Prussian Blue Modified Electrode via Ionic Liquid Treatment

This article first reports the preparation of a Prussian blue (PB) modified electrode with improved electrochemical properties at the functionalized glass carbon electrode (GC) by imidazolium based ionic liquid. The molecular ionic liquid film on the GC electrode has been found to influence the electrodeposition of PB by a way of enhancement of voltammetric currents, suggesting efficient electrodepositon. Such efficient electrodeposition was caused by the static electric effect which existed between the positively charged imidazolium group on the electrode surface and the negative ferric‐ferricyanide in solution. Compared with the PB/GC electrode, the PB/[Bmim][Cl]/GC electrode showed much better electrochemical stability after successive potential cycling for 250 cycles. A comparative study on amperometric responses of both electrodes to reduce H₂O₂ was also investigated. PB/[Bmim][Cl]/GC electrode showed a better electrocatalytic performance to H₂O₂ with wider linear detection range and higher sensitivity than that at the electrode without [Bmim][Cl]. Furthermore, the kinetics for both electrodes was discussed. The PB/[Bmim][Cl]/GC electrode possessed a greater diffusion coefficient.     

碱性电解质中BiVO4膜电极的光电化学性质

采用刮刀法制备了压制BiVO4膜电极,研究了电极在0 1 mol/L NaOH中的光电化学性质. 发现相对于中性电解质,其在碱性电解质中的光电流增大,稳定性提高. 结合循环伏安分析中间产物的还原特性,认为光催化氧化水作用是通过四空穴亲核反应历程进行的. pH值升高有利于亲核反应,过氧化物中间产物累积较少. 在较高的偏压的碱性溶液中,光氧化水的机制可能涉及铋的中间物质.