NiFe水滑石纳米片阵列负载Ru用于提升碱性电催化析氢和析氧性能

通过离子交换的方式将Ru负载到NiFe水滑石（LDH）纳米阵列表面得到（Ru/NiFe LDH），Ru的引入显著提升了NiFe LDH的活性比表面积，暴露了更多的活性位点，同时调控了其电子结构，大大提升了其本征催化活性。在碱性条件下，催化析氢反应时仅需50 mV的过电位即可达到10 mA·cm^-2的电流密度，Tafel斜率为52.3 mV·dec^-1。而相同条件下原始NiFe LDH达到10mA·cm^-2的电流密度则需要226 mV的过电位，Tafel斜率为157.5 mV·dec^-1。同时制备的Ru/NiFe LDH也展现出了良好的析氧催化活性，在50 mA·cm^-2的电流密度下，过电位仅为231 mV，而NiFe LDH则需237 mV。Ru/NiFe LDH在长时间的电催化条件下依然能保持良好的工作稳定性。     

泡沫镍原位负载双金属AlCo层状双氢氧化物纳米催化剂高效电催化析氧反应

经一步水热法在泡沫镍（NF）上原位生长获得了AlCo-LDH/NF （LDH=层状双氢氧化物）催化剂。基于AlCo-LDH的高表面积和良好相界面,催化剂表现出了优异的电催化析氧反应（OER）活性。在碱性介质中,当电流密度为200 mA·cm^-2时,AlCo₃-LDH/NF催化剂具有419 mV的低过电位和50.04 mV·dec^-1的低Tafel斜率。     

一步法合成的FeOOH/黑磷纳米复合材料协同实现体系优异的析氧性能

通过水热法,在黑磷(BP)纳米片表面生长FeOOH纳米材料,制备出FeOOH/BP纳米复合材料。作为电化学析氧反应(OER)催化剂,该复合材料在20 mA·cm^-2时的过电位仅为191 mV,Tafel斜率为49.9 mV·dec^-1;在循环1 000圈后,过电位仅仅增加了3 mV,且循环过程中元素价态不变,表现出优秀的稳定性。纳米FeOOH负载于BP表面,客观上能隔断氧气对BP的氧化,保护BP的载流子传导性能。同时,生长的FeOOH颗粒尺度小,结晶性弱,这有利于丰富其活性位点,增大活性面积。     

MoSe2/Co-MOF/NF复合材料的制备及电催化产氧性能

设计高效的催化剂对于电解水制氢至关重要。基于过渡金属硒化物(TMSe)的高催化活性和金属有机骨架(MOFs)的灵活结构,我们提出了一种将MOFs与TMSe复合的策略,在导电基底泡沫镍(NF)上生长的复合材料不仅继承了2种单体的优点,还有效地改善了MOFs导电性差、TMSe易团聚的缺点。MoSe₂/Co-MOF/NF在碱性溶液中展示出优异的电催化产氧活性,在电流密度为10 mA·cm^-2时其过电位仅为242 mV,塔菲尔斜率仅为50.64 mV·dec^-1。此外,该材料在碱性溶液中经1 000圈循环伏安(CV)循环测试和30 h的恒电压电解测试均表现出良好的稳定性。     

CuCo2O4/NiFe层状双金属氢氧化物核壳纳米花球阵列的高效析氧反应

采用界面工程策略在泡沫镍(NF)上制备了CuCo₂O₄/NiFe层状双金属氢氧化物(LDH)(CuCo₂O₄/NiFe-LDH@NF)核壳纳米花球阵列。研究表明,电子通过CuCo₂O₄和NiFe-LDH耦合界面发生转移,导致核心CuCo₂O₄处于富电子状态,从而提高了反应速率。非晶态NiFe-LDH外壳不仅为电子/物质提供更多的传输通道和增加活性位点。同时,还能在电催化析氧反应(OER)中保护核心CuCo₂O₄免受强碱腐蚀。因此,在1.0 mol·L^-1 KOH溶液中,将CuCo₂O₄/NiFe-LDH@NF用作OER催化剂时,仅需191mV的低过电位即可实现10 mA·cm^-2的电流密度和31 mV·dec^-1的低Tafel斜率。此外,CuCo₂O₄/NiFe-LDH@NF在长时间的工作中能够保证催化性能、晶体结构、形貌结构和组成的稳定。     

MoSe2/Co-MOF/NF复合材料的制备及电催化产氧性能

设计高效的催化剂对于电解水制氢至关重要。基于过渡金属硒化物(TMSe)的高催化活性和金属有机骨架(MOFs)的灵活结构，我们提出了一种将MOFs与TMSe复合的策略，在导电基底泡沫镍(NF)上生长的复合材料不仅继承了2种单体的优点，还有效地改善了MOFs导电性差、TMSe易团聚的缺点。MoSe₂/Co-MOF/NF在碱性溶液中展示出优异的电催化产氧活性，在电流密度为10 mA·cm^-2时其过电位仅为242 mV，塔菲尔斜率仅为50.64 mV·dec^-1。此外，该材料在碱性溶液中经1 000圈循环伏安(CV)循环测试和30 h的恒电压电解测试均表现出良好的稳定性。     

硼、磷共掺杂铁钴双金属材料的制备及其电催化析氧性能

采用一步水热法合成了硼、磷共掺杂铁钴材料(Fe-Co-B-P)。借助扫描电子显微镜(SEM)、X射线衍射(XRD)、X射线光电子能谱(XPS)、傅里叶变换红外光谱(FT-IR)等技术对所合成材料的形貌、结构和组成进行表征。利用线性扫描伏安(LSV)、循环伏安(CV)、电化学阻抗谱(EIS)等技术研究材料电化学析氧反应(OER)性能。结果表明，Fe-Co-B-P表面疏松且粗糙，颗粒间有许多空隙。在电流密度为10和100 mA·cm^-2时，其过电势分别为278和309 mV，Tafel斜率为24 mV·dec^-1，说明该材料具有较优的电催化析氧性能。其在连续进行10 h的计时电位测试过程中，电势基本保持在1.55 V (vs RHE)，表明该催化剂具有较好的电化学稳定性。这是由于铁钴双金属与硼、磷非金属之间的协同作用促进了电子的传递。     

片状NiWP@多面体NiWO电催化剂的制备及其析氢性能

采用水热法在泡沫镍上制备多面体镍钨氧化物(NiWO)前驱体,然后在不同温度下对前驱体进行磷化处理,获得片状镍钨磷化物(NiWP)@多面体NiWO复合电催化剂。结果表明：优化磷化温度可显著改善片状NiWP@多面体NiWO电催化析氢性能。当磷化温度为450℃时,所得电极具有较好的析氢催化活性,在1 mol·L^-1 KOH中仅需115 mV的过电位就能达到10 mA·cm^-2的电流密度,Tafel斜率为85 mV·dec^-1,与铂片的Tafel斜率相近。此外,24 h长期稳定性测试结果表明该电催化剂具有良好的稳定性。优异的性能可归因于片状NiWP@多面体NiWO复合结构增大了催化活性面积,减小了电荷/质量传输阻力,使得析氢反应中电子转移速度加快,反应动力学性能提高。     

一步法合成的FeOOH/黑磷纳米复合材料协同实现体系优异的析氧性能

通过水热法，在黑磷(BP)纳米片表面生长FeOOH纳米材料，制备出FeOOH/BP纳米复合材料。作为电化学析氧反应(OER)催化剂，该复合材料在20 mA·cm^-2时的过电位仅为191 mV，Tafel斜率为49.9 mV dec^-1；在循环1 000圈后，过电位仅仅增加了3 mV，且循环过程中元素价态不变，表现出优秀的稳定性。纳米FeOOH负载于BP表面，客观上能隔断氧气对BP的氧化，保护BP的载流子传导性能。同时，生长的FeOOH颗粒尺度小，结晶性弱，这有利于丰富其活性位点，增大活性面积。     

一步法合成的FeOOH/黑磷纳米复合材料协同实现体系优异的析氧性能

通过水热法,在黑磷(BP)纳米片表面生长FeOOH纳米材料,制备出FeOOH/BP纳米复合材料。作为电化学析氧反应(OER)催化剂,该复合材料在20 mA·cm^-2时的过电位仅为191 mV,Tafel斜率为49.9 mV dec^-1;在循环1 000圈后,过电位仅仅增加了3 mV,且循环过程中元素价态不变,表现出优秀的稳定性。纳米FeOOH负载于BP表面,客观上能隔断氧气对BP的氧化,保护BP的载流子传导性能。同时,生长的FeOOH颗粒尺度小,结晶性弱,这有利于丰富其活性位点,增大活性面积。     

Facile one-step synthesis of Ru doped NiCoP nanoparticles as highly efficient electrocatalysts for oxygen evolution reaction

Transition metal phosphides (TMPs) as ever-evolving electrocatalytic materials have attracted increasing attention in water splitting reactions owing to their cost-effective, highly active and stable catalytic properties. This work presents a facile synthetic route to NiCoP nanoparticles with Ru dopants which function as highly efficient electrocatalysts for oxygen evolution reaction (OER) in alkaline media. The Ru dopants induced a high content of Ni and Co vacancies in NiCoP nanoparticles, and the more defective Ru doped NiCoP phase than undoped NiCoP ones led to a greater number of catalytically active sites and improved electrical conductivity after undergoing electrochemical activation. The Ru doped NiCoP catalyst exhibited high OER catalytic performance in alkaline media with a low overpotential of 281 mV at 10 mA cm⁻² and a Tafel slope of 42.7 mV dec⁻¹.     

The preparation of ionic liquid based iron phosphate/CNTs composite via microwave radiation for hydrogen evolution reaction and oxygen evolution reaction

Water electrolysis is a promising method for hydrogen production, so the preparation of low-cost and efficient electrocatalysts with a quick and simple procedure is crucial. Herein, iron phosphate (Fe₇(PO₄)₆) was prepared via microwave radiation using ionic liquid (IL) as iron and phosphorus dual-source. This method is simple and rapid, and the product can be directly used as electrocatalysts without further treatment. The experimental results show that the IL can influence the morphology and electrocatalytic performance. Moreover, the addition of carbon nanotubes (CNTs) is favorable for formation of iron phosphate nanoparticles to improve the catalytic activities. As hydrogen evolution reaction (HER) catalyst, this iron phosphate/CNTs exhibits an onset overpotential of 120 mV, Tafel slope of 32.9 mV dec^-1, and current densities of 10 mA cm⁻² at overpotential of 185 mV. Then, it obtains a good activity for oxygen evolution reaction (OER) with a low onset potential of 1.48 V, Tafel slope of 73.3 mV dec^-1, and it only needs an overpotential of 300 mV to drive the 10 mA cm⁻². This bifunctional catalyst also shows good durability for HER and OER. This microwave-assisted method provides an outstanding strategy to prepare iron phosphate in a simple and fast process with good catalytic performance for water splitting.     

Hierarchical Architectures Based on Ru Nanoparticles/Oxygen-Rich-Carbon Nanotubes for Efficient Hydrogen Evolution

Highly active and durable electrocatalysts are essential for producing hydrogen fuel through the hydrogen evolution reaction (HER). Here, a uniform deposition of Ru nanoparticles strongly interacting with oxygen-rich carbon nanotube architectures (Ru-OCNT) through ozonation and hydrothermal approaches has been designed. The hierarchical structure of Ru-OCNT is made by self-assembly of oxygen functionalities of OCNT. Ru nanoparticles interact strongly with OCNT at the Ru/OCNT interface to give excellent catalytic activity and stability of the Ru-OCNT, as further confirmed by density functional theory. Owing to the hierarchical structure and adjusted surface chemistry, Ru-OCNT has an overpotential of 34 mV at 10 mA cm⁻² with a Tafel slope of 27.8 mV dec⁻¹ in 1 M KOH, and an overpotential of 55 mV with Tafel slope of 33 mV dec⁻¹ in 0.5 M H₂SO₄. The smaller Tafel slope of Ru-OCNT than Ru-CNT and commercial Pt/C in both alkaline and acidic electrolytes indicates high catalytic activity and fast charge transfer kinetics. The as-proposed chemistry provides the rational design of hierarchically structured CNT/nanoparticle electrocatalysts for HER to produce hydrogen fuel.