铁掺杂二硫化钼纳米片作为高效的双功能电解水催化剂

设计和合成具有高活性、耐久性的非贵金属电解水催化剂对能量转化和储存具有重要意义。在研究中,通过硝酸铁、硫代乙酰胺与二水钼酸钠在无水乙醇中的水热反应制备了铁掺杂二硫化钼(Fe-MoS₂)的纳米材料。Fe-MoS₂具有较高的析氧反应(OER)活性,在1 mol/L KOH电解质中,当电流密度为10 mA·cm^-2时过电位为250 mV,塔菲尔斜率为219 mV·dec^-1,而且Fe-MoS₂在这些条件下可稳定超过10 h以上。同时其具有良好的析氢反应(HER)活性,在0.5 mol/L H₂SO₄电解质中,当电流密度为10 mA cm^-2时过电位为220 mV。此外,在1 mol/L KOH电解液中,Fe-MoS₂/C(阳极)//Fe-MoS₂/C(阴极)两电极体系具有良好的电解水催化活性,在10 mA cm^-2的电流密度下低电位为1.77 V。为开发...     

深共晶溶剂中电沉积制备Co-Fe-Gd/NF电极及其析氢性能研究

为了制备出在碱性环境中具备高效能的廉价析氢电极催化剂,选择不同的沉积电位在氯化胆碱-尿素(ChCl-urea)中电沉积制备出五种Co-Fe-Gd/NF电极催化剂。通过扫描电镜(SEM)和光谱仪(EDX)对电极表面形貌、元素含量及分布情况进行表征,X射线光电子能谱(XPS)对电极表面化学性质进行表征。结合线性扫描伏安法(LSV)、电化学阻抗技术(EIS)和循环伏安法(CV)电化学测试结果,表明-1.24 V沉积电位下制备的Co-Fe-Gd/NF-3电极具备优异的析氢催化性能,在10 mA·cm^-2时的过电位仅为71 mV,最小的塔菲尔斜率(45 mV·dec^-1)与电荷转移电阻(0.28503Ω·cm^-2)表明其具备更快的析氢反应动力学过程,电化学活性表面积(ECSA)最大为390.5,为析氢过程提供更多的反应活性位点。对电极进行循环伏安耐久性测试与计时电流法(I-t)测试,结果表明Co-Fe-Gd/NF-3电极催化剂在碱性环境中稳定性良好。     

用于海水电解质中高效分解水合肼的镍-钼/钨双金属纳米合金（英文）

利用水合肼氧化反应(HzOR)取代缓慢的析氧反应(OER)是一种可以在海水裂解中长期产生氢气并抑制不利的析氯反应(ClER)的方法.然而,很少有催化剂能够满足在双电极系统中同时呈现出优异的析氢反应(HER)和HzOR以达到较低的电池电压的要求.在此,我们报道了双金属Ni₄Mo/Ni₄W纳米合金作为双功能催化剂,该催化剂对HER(-7 mV,10 mA cm^-2)和HzOR (-16 mV,10 mA cm^-2)具有显著的催化活性.在1.0 mol L^-1 KOH/2.0 molL^-1NaCl/0.1 mol L^-1 N₂H₄电解液中,双电极系统需要34,295和548 mV的低电池电压就能达到10,100和200mAcm^-2.密度泛函理论计算表明,Ni-Mo/W耦合不仅可以降低水解离的自由能和氢的吸附/脱附,而且可以优化吸附水合肼中间体的脱氢动力学.     

耐蚀镍基催化剂的制备及电解海水性能的研究

开发抑制析氯的竞争反应和氯离子腐蚀的高效电解海水催化剂是至关重要的。通过两步法(激光扫描法+浸泡置换法)在泡沫镍上快速制备了一种高活性且耐蚀的NiFe-LDH@MnO₂/NF电解海水催化剂。该催化剂中NiFe-LDH提高了催化反应的活性，MnO₂层防止催化剂被氯侵蚀，二者的协同作用使催化剂在碱性盐水介质中表现出优异的析氧性能。所制备的NiFe-LDH@MnO₂/NF催化剂在10 mA/cm²的电流密度下，过电位仅为270 mV,在100 mA/cm²的大电流密度下过电位为360 mV,且在10 mA/cm²的电流密度下可稳定催化析氧100 h,为工业电解海水制氢催化剂的制备提供理论指导。     

界面工程用于提高CoP-Co2P多晶型物在全pH值析氢反应和碱性全解水反应中的电催化性能(英文)

开发具有丰富活性位点和高本征活性的磷化钴催化剂,用于高效且稳定的析氢反应(HER)和析氧反应(OER)具有重要意义.本工作通过精准地控制球形膦酸钴的热还原温度合理地构建了新型的碳包裹的CoP-Co₂P多晶型物.独特的多级孔结构和CoP-Co₂P之间的异质界面不仅提高了活性位点的数量,而且还保证了优异的内在催化活性.所制备的催化剂展现出优异的电催化活性和稳定性(对于全pH值H E R(0.5 mol L~(-1H₂SO₄:81 mV@10 mA cm^-2; 1.0 mol L^-1KOH:109 mV@10 mA cm^-2; 1.0 mol L^-1PBS:227 mV@10 mA cm^-2)和碱性OER(1.0 mol L^-1KOH:1.53 V@10 mA cm^-2)).在作为双电极电解槽中全解水反应的双功能电催化剂时,该材料可以在1.60 V的低电...     

非晶Nd-Ni-B/NF稀土复合电极材料的制备及其析氢性能

本研究采用简单的一步化学沉积法制备非晶纳米Nd-Ni-B/NF稀土复合电极并研究其析氢(Hydrogen evolution reaction, HER)性能。通过各种测试方法对纳米电极材料进行物相分析和形貌表征,并探索其电催化析氢性能和稳定性。结果表明, 稀土Nd可提高电极的电催化析氢性能, 当硝酸钕浓度为3 g?L^-1时, 恒温35 ℃下施镀1 h, 制备的Nd-Ni-B/NF电极析氢性能最佳。Nd-Ni-B/NF(Nickel foam)电极在1.0 mol?L^-1KOH 溶液中, 20 mA?cm^-2电流密度下的析氢过电位仅为180 mV, Tafel斜率为117 mV?dec^-1, 析氢反应由Volmer-Heyrovsky步骤控制。此外, Nd-Ni-B/NF电极具有优越的电化学稳定性, 在持续电解12 h或2000次循环伏安测试后, 催化剂的活性没有明显衰减。     

多维镍钴硫化物异质结电催化剂用于高效全水解（英文）

异质结构工程在高效全解水催化剂方面具有突出的应用前景.然而,生产廉价高效的双功能电催化剂仍然是一个巨大的挑战.因此,我们受构树启发,通过一种简单的方法在泡沫镍基体上合成了高催化活性和稳定性的Co₉S₈@CoNi₂S₄/NF异质结.该过程包括NiCo层状双氢氧化物在泡沫镍基体上的原位生长和原位衍生ZIF-67,并伴随S原子掺杂.所获得的Co₉S₈@CoNi₂S₄/NF多维度异质结包括一维纳米线、二维纳米片和纳米颗粒.优化的Co₉S₈@CoNi₂S₄/NF中硫含量为10%,在1.0 mol L^-1KOH溶液中,电流密度为10 mA cm^-2时,具有优异的电催化活性,其析氢和析氧过电位分别为68和170 mV,优于最近报道的过渡金属基电催化剂.该催化剂优异的催化性能主要归因于CoNi     

NH2-MoS2@BP的制备及其电催化析氢性能研究

采用液相剥离法制备二维黑磷烯纳米片(BP),将其与改性的MoS₂通过水热法合成得到NH₂-MoS₂@BP,利用XRD、SEM、TEM对材料的形貌结构进行表征，并通过三电极体系测试析氢性能。结果表明，NH₂-MoS₂@BP形貌呈片层结构，BP在催化剂中颗粒很小且均匀的分布在其表面。在0.5mol/L H₂SO₄溶液中，当电流密度为10mA/cm²时，氨基的加入使催化剂的析氢过电位降低了20mV,BP的加入使催化剂的析氢过电位降低了90mV,塔菲尔斜率为95mV/dec,表明BP有利于改善改性MoS₂的催化性能。此外，连续的循环伏安测试表明NH₂-MoS₂@BP具有较好的电催化稳定性。     

金属镍铜负载钒氧化物的高效电解产氢性能

镍基电极材料是碱性电解水中最具工业应用前景的过渡金属催化剂,而其缓慢的析氢反应动力学及低活失活问题仍亟待解决。本研究以泡沫镍(NF)为基底,采用一步循环伏安法制备了主晶相为独立分相的多晶态金属镍铜合金、夹杂有少量非晶态V₂O₅相、具有三维多孔团簇结构的金属镍铜负载钒氧化物电催化剂(VO_x-NiCu/NF)。纳米颗粒、团簇交织形成的微米孔及泡沫镍的一级微孔共同构成了VO_x-NiCu/NF的三级多孔微纳结构,使其电催化活性面积增加了28倍,并在析氢反应中表现出优异的催化性能。在碱性介质中,获得-10 mA·cm^-2的析氢电流密度,VO_x-NiCu/NF需要的过电势(η₁₀)仅为35 mV,表现出类铂的催化活性,具有优异的长效稳定性及强劲的耐用性。电极表面形成的多孔团簇结构,显著增加了催化活性位点并为物质传递提供大量通道。镍铜合金及非晶态V₂O₅相,在一定程度协同改善了材料的固有析氢活性。理想的组...     

MnNiCoCrFe多孔高熵合金的电催化析氧性能

用化学腐蚀方法制备出3D多孔自支撑型Mn₅₀Fe_12.5Co_12.5Ni_12.5Cr_12.5高熵合金。电化学测试结果表明，将这种高熵合金放入1 mol/L KOH的碱性溶液中，电流密度为10 mA·cm^-2时过电位为281 mV,Tafel斜率为63 mV/dec,表明其电催化性能优于商业RuO₂的性能。在电流密度为50 mA·cm^-2的条件下连续工作50 h，工作电压没有明显的升高，表明这种富锰高熵电催化电极材料具有优异的析氧稳定性。电化学阻抗谱表明，这种自支撑型结构的块体高熵合金催化剂具有出色的导电性，与负载型催化剂相比其电子转移能力显著提高。     

Co2Ni1O4/不锈钢复合材料的制备及其电催化析氧性能

电解水包括析氢反应(HER)与析氧反应(OER),由于OER是复杂的4电子转移过程,制作出具有优异耐久性的高活性的非贵金属OER电催化剂对于电解水至关重要。为了降低成本,选择304型不锈钢网(SS)作为基体,使用电沉积的方法制备钴-镍双氢氧化物,利用真空煅烧的方法制备钴-镍氧化物。使用XRD、SEM、TEM、XPS和电化学工作站对Co₂Ni₁O₄/SS复合材料的晶体结构、形貌和电催化OER性能进行了研究。结果表明:电沉积制备的钴-镍双氢氧化物煅烧之后转变成尖晶石结构的钴-镍氧化物;在不锈钢表面成功合成了大量密集的层状结构;在1.0 mol/L KOH电解液中,Co₂Ni₁O₄/SS电极表现出优异的OER电催化性能,达到10 mA·cm?2电流密度时所需要的过电位仅为240 mV,Tafel斜率为53.92 mV·dec?1,并且表现出优异的稳定性。      

Mn掺杂Co-Al金属氢氧化物的制备及其全解水电化学性能

以Co基氢氧化物为基础用异质元素掺杂方式引入Mn并与Co协同,制备出Mn掺杂Co-Al层状双金属氢氧化物(Mn-CoAl LDH).在1 mol/L的KOH碱性电解质中,电流密度达到10 mA·cm-2时Mn-CoAl LDH的全解水电势为1.66V,其性能远优于Co-A1层状双金属氢氧化物(CoAl LDH)、Ni2...     

Bimetallic Ni–Mo nitride@C3N4 for highly active and stable water catalysis

Non-noble metal electrocatalysts for water cracking have excellent prospects for development of sustainable and clean energy. Highly efficient electrocatalysts for the oxygen evolution reaction (OER) are very important for various energy storage and conversion systems such as water splitting devices and metal‒air batteries. This study prepared a NiMo₄@C₃N₄ catalyst for OER and hydrogen evolution reaction (HER) by simple methods. The catalyst exhibited an excellent OER activity based on the response at a suitable temperature. To drive a current density of 10 mA·cm⁻² for OER and HER, the overpotentials required for NiMo₄@C₃N₄-800 (prepared at 800 °C) were 259 and 118 mV, respectively. A two-electrode system using NiMo₄@C₃N₄-800 needed a very low cell potential of 1.572 V to reach a current density of 10 mA·cm⁻². In addition, this catalyst showed excellent durability after long-term tests. It was seen to have good catalytic activity and broad application prospects.     

Ternary NiCoP nanosheet arrays: An excellent bifunctional catalyst for alkaline overall water splitting

Exploring bifunctional catalysts for the hydrogen and oxygen evolution reactions (HER and OER) with high efficiency,low cost,and easy integration is extremely crucial for future renewable energy systems.Herein,ternary NiCoP nanosheet arrays (NSAs) were fabricated on 3D Ni foam by a facile hydrothermal method followed by phosphorization.These arrays serve as bifunctional alkaline catalysts,exhibiting excellent electrocatalytic performance and good working stability for both the HER and OER.The overpotentials of the NiCoP NSA electrode required to drive a current density of 50 mA/cm2 for the HER and OER are as low as 133 and 308 mV,respectively,which is ascribed to excellent intrinsic electrocatalytic activity,fast electron transport,and a unique superaerophobic structure.When NiCoP was integrated as both anodic and cathodic material,the electrolyzer required a potential as low as ～1.77 V to drive a current density of 50 mA/cm2 for overall water splitting,which is much smaller than a reported electrolyzer using the same kind of phosphide-based material and is even better than the combination of Pt/C and Ir/C,the best known noble metal-based electrodes.Combining satisfactory working stability and high activity,this NiCoP electrode paves the way for exploring overall water splitting catalysts.     

Metal–Organic Framework–Derived Mesoporous B-Doped CoO/Co@N-Doped Carbon Hybrid 3D Heterostructured Interfaces with Modulated Cobalt Oxidation States for Alkaline Water Splitting (Small 35/2023)

Heteroatom-doped transition metal-oxides of high oxygen evolution reaction (OER) activities interfaced with metals of low hydrogen adsorption energy barrier for efficient hydrogen evolution reaction (HER) when uniformly embedded in a conductive nitrogen-doped carbon (NC) matrix, can mitigate the low-conductivity and high-agglomeration of metal-nanoparticles in carbon matrix and enhances their bifunctional activities. Thus, a 3D mesoporous heterostructure of boron (B)-doped cobalt-oxide/cobalt-metal nanohybrids embedded in NC and grown on a Ni foam substrate (B-CoO/Co@NC/NF) is developed as a binder-free bifunctional electrocatalyst for alkaline water-splitting via a post-synthetic modification of the metal–organic framework and subsequent annealing in different Ar/H₂ gas ratios. B-CoO/Co@NC/NF prepared using 10% H₂ gas (B-CoO/Co@NC/NF [10% H₂]) shows the lowest HER overpotential (196 mV) and B-CoO/Co@NC/NF (Ar), developed in Ar, shows an OER overpotential of 307 mV at 10 mA cm⁻² with excellent long-term durability for 100 h. The best anode and cathode electrocatalyst-based electrolyzer (B-CoO/Co@NC/NF (Ar)(+)//B-CoO/Co@NC/NF (10% H₂)(−)) generates a current density of 10 mA cm⁻² with only 1.62 V with long-term stability. Further, density functional theory investigations demonstrate the effect of B-doping on electronic structure and reaction mechanism of the electrocatalysts for optimal interaction with reaction intermediates for efficient alkaline water-splitting which corroborates the experimental results.     

FeOOH-Ni(OH)2复合材料的制备及其电催化析氧性能

以碳纤维布（CFC）为基底,通过两步法(恒电流电沉积法、溶剂热法)成功制备了FeOOH-Ni(OH)₂复合材料。与FeOOH和Ni(OH)₂相比,该FeOOH-Ni(OH)₂复合材料作为电催化剂时,电催化析氧反应(OER)活性显著提高。在1 mol/L KOH电解质溶液中,达到10 mA·cm?2电流密度时所需要的过电位仅为270 mV,Tafel斜率为78 mV/dec,电化学阻抗谱进一步揭示了电解过程中良好的动力学特性。FeOOH-Ni(OH)₂复合材料在碱性介质中具有优异的稳定性,其在高电流密度下(50 mA·cm?2)的过电势经过连续24 h的测试之后几乎没有发生明显变化。FeOOH和Ni(OH)₂之间的强电子相互作用和协同效应有效提高了电导性,促进了电荷转移;此外,这种核壳结构有效增强了电催化活性面积,进而增强了其电催化析氧性能。      

氮掺杂碳负载表面部分暴露的CoFe2O4用于高性能催化析氧反应

开发价格低廉、储量丰富、高效的析氧反应(OER)电催化剂对于可持续能源的转换具有重要意义。目前,虽然尖晶石型二元过渡金属氧化物表现出了很有潜力的OER活性,但其固有的低电导率一定程度上降低了其电化学性能。本文提出了一种通过金属有机框架(MOF)辅助合成表面部分暴露的CoFe₂O₄纳米颗粒负载在氮掺杂碳基底上(CoFe₂O₄@NC)的方法,且CoFe₂O₄@NC具有优良的催化活性。在碱性介质中,CoFe₂O₄@NC表现出了优异的OER活性,在10 mA·cm^-2电流密度的过电势仅为1.517 V,Tafel斜率为87 mV·dec^-1,这是由于CoFe₂O₄@NC具有足够暴露的活性位点和较高的电子转移能力。此外,CoFe₂O₄@NC能稳定运行15 h,具有出色的稳定性。该工作将为探索经...     

3D Nitrogen‐Anion‐Decorated Nickel Sulfides for Highly Efficient Overall Water Splitting

Developing non‐noble‐metal electrocatalysts with high activity and low cost for both the oxygen evolution reaction (OER) and hydrogen evolution reaction (HER) is of paramount importance for improving the generation of H₂ fuel by electrocatalytic water‐splitting. This study puts forward a new N‐anion‐decorated Ni₃S₂ material synthesized by a simple one‐step calcination route, acting as a superior bifunctional electrocatalyst for the OER/HER for the first time. The introduction of N anions significantly modifies the morphology and electronic structure of Ni₃S₂, bringing high surface active sites exposure, enhanced electrical conductivity, optimal HER Gibbs free‐energy (ΔG_H*), and water adsorption energy change (ΔG_H2O*). Remarkably, the obtained N‐Ni₃S₂/NF 3D electrode exhibits extremely low overpotentials of 330 and 110 mV to reach a current density of 100 and 10 mA cm^?2 for the OER and HER in 1.0 m KOH, respectively. Moreover, an overall water‐splitting device comprising this electrode delivers a current density of 10 mA cm^?2 at a very low cell voltage of 1.48 V. Our finding introduces a new way to design advanced bifunctional catalysts for water splitting.     

Nitrogen Engineering on 3D Dandelion‐Flower‐Like CoS2 for High‐Performance Overall Water Splitting

Searching for highly efficient and stable bifunctional electrocatalysts toward hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) is highly desirable for the practical application of water electrolysis under alkaline electrolyte. Although electrocatalysts based on transition metal sulfides (TMSs) are widely studied as efficient (pre)catalysts toward OER under alkaline media, their HER performances are far less than the state‐of‐the‐art Pt catalyst. Herein, the synthesis of nitrogen doped 3D dandelion‐flower‐like CoS₂ architecture directly grown on Ni foam (N‐CoS₂/NF) is reported that possesses outstanding HER activity and durability, with an overpotential of 28 mV to obtain the current density of 10 mA cm^?2, exceeding almost all the documented TMS‐based electrocatalysts. Density functional theory calculations and experimental results reveal that the d‐band center of CoS₂ could be efficiently tailored by N doping, resulting in optimized adsorption free energies of hydrogen (ΔG_*H) and water , which can accelerate the HER process in alkaline electrolyte. Besides, the resulting N‐CoS₂/NF also displays excellent performance for OER, making it a high‐performance bifunctional electrocatalyst toward overall water splitting, with a cell voltage of 1.50 V to achieve 10 mA cm^?2.     

Vertical Growth of 2D Amorphous FePO4 Nanosheet on Ni Foam: Outer and Inner Structural Design for Superior Water Splitting

Rational design of highly efficient bifunctional electrocatalysts based on 3D transition‐metal‐based materials for oxygen evolution reaction (OER) and hydrogen evolution reaction (HER) is of great importance for sustainable energy conversion processes. Herein, a novel strategy involving outer and inner structural engineering is developed for superior water splitting via in situ vertical growth of 2D amorphous FePO₄ nanosheets on Ni foam (Am FePO₄/NF). Careful experiments and density functional theory calculations show that the inner and outer structural engineering contributing to the synergistic effects of 2D morphology, amorphous structure, conductive substrate, and Ni?Fe mixed phosphate lead to superior electrocatalytic activity toward OER and HER. Furthermore, a two‐electrode electrolyzer assembled using Am FePO₄/NF as an electrocatalyst at both electrodes gives current densities of 10 and 100 mA cm^?2 at potentials of 1.54 and 1.72 V, respectively, which is comparable to the best bifunctional electrocatalyst reported in the literature. The strategies, introduced in the present work, may open new opportunities for the rational design of other 3D transition‐metal‐based electrocatalyst through an outer and inner structural control to strengthen the electrocatalytic performance.