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1.
郭芬岈  马雨涵  戎怡珅  黎挺挺 《化学试剂》2019,41(11):1110-1114
过渡金属硫化物因其制备简单、导电性好以及具有丰富的氧化还原性质被广泛用作电催化剂。在导电基底上原位生长复合材料被认为可有效提高催化剂的电催化性能。基于此,利用简单、可控的电沉积法,以泡沫铜作为导电基底,以硝酸铜和硝酸钴作为铜源和钴源原位制备了Co_9S_8-Cu S纳米片阵列。在三电极体系中,将Co_9S_8-Cu S纳米片阵列作为阳极在1 mol/L KOH溶液中得到了优异的电催化析氧性能,Co_9S_8-Cu S纳米片阵列获取50 m A/cm~2电流密度所需的过电位仅为370 m V,其Tafel斜率低至108 m V/dec,其优异的电催化析氧性能归因于较大的催化活性面积以及复合材料中Co_9S_8与Cu S之间的协同作用。  相似文献   

2.
赵娟  吴梦成  雷惊雷  李凌杰 《化工学报》2022,73(4):1575-1584
采用一步水热法,由泡沫钼镍合金同时提供钼源和镍源在泡沫钼镍合金表面原位制备了Ni3S2@Mo2S3,并将其直接作为自支撑电极用于催化碱性介质中的电解水析氧反应(OER)。利用多种表征测试技术研究了样品的形貌、组成、OER电催化性能,结果显示:Ni3S2@Mo2S3呈纳米板形貌,由六方Ni3S2和单斜Mo2S3按5∶1的比例复合而成;在1 mol·L-1 KOH 溶液中,Ni3S2@Mo2S3催化剂仅需要170 mV过电位就可达到10 mA·cm-2电流密度(欧姆补偿后),且在50 h的稳定性测试期间性能基本无衰减,优于贵金属催化剂IrO2以及文献报道的Ni-Mo基复合催化剂。Ni3S2@Mo2S3具有优异电催化性能的原因可归于不同过渡金属化合物的协同作用、原位生长自支撑、电化学活性面积大以及液下疏气性等因素。  相似文献   

3.
在全pH(0~14)范围下设计开发低廉、高活性的析氢电催化剂对新能源开发和利用具有重要实际意义。通过简单的溶剂热法在镍网(NF)上原位构筑了纳米线结构MoS2/Ni3S2/NF电催化剂,该催化剂在全PH范围下表现出优异的析氢(HER)活性。电化学测试结果表明,使用41 mg四硫代钼酸铵制得的MoS2/Ni3S2/NF-41电极,在电流密度10 mA/cm2时,其在碱性(1 moL/L KOH,pH=14)、中性(0.5 moL/L PBS,pH=7)和酸性(0.5 moL/L H2SO4,pH=0)介质中HER过电位分别为87、113和195 mV,并相应表现出较低的Tafel斜率。另外,SEM、TEM、EDX、XPS等表征手段表明该催化剂具有良好的结构稳定性。本研究为过渡金属硫化物在全pH环境下高效析氢提供了新途径。  相似文献   

4.
在镀液中悬浮粒径为200~400 nm的ZrO2固体颗粒,以电沉积方法制备了Ni-S-Co/ZrO2复合电极。XRD和SEM测试结果表明,沉积层由非晶态的Ni、Co、S和单斜晶型的ZrO2粒子组成。镀层表面呈团粒状结构,无裂隙,与基体结合牢固。电化学测试结果表明,25℃时,Ni-S-Co/ZrO2复合电极在质量分数28%NaOH水溶液中,在电流密度100 mA/cm2下的超电势为145 mV,与未复合纳米ZrO2粒子的Ni-S-Co电极相比降低了50 mV。表明超细ZrO2的掺入有效提高了电极对析氢反应的催化效果。实验表明,沉积的最佳电流密度为70 mA/cm2,最适宜的ZrO2用量为15 g/L,采用Ni-S-Co作为过渡层可以显著改善复合镀层与基体的结合。  相似文献   

5.
利用一步水热法成功制备了In2S3/CdIn2S4异质结微球催化剂,通过降解甲基橙(MO)、酸性橙Ⅱ(AOⅡ) 和罗丹明B(RhB)来评价所制备催化剂的活性。实验结果表明,In2S3/CdIn2S4异质结微球对MO、AOⅡ和RhB的光催化降解率分别达到了87%、75%和96%,明显高于催化剂In2S3和CdIn2S4。瞬态光电流和阻抗测试结果表明,In2S3/CdIn2S4异质结微球受光激发产生的电子空穴对能快速得到分离。捕获主要活性物种实验表明,该反应体系中主要是超氧自由基和空穴起关键性作用。In2S3/CdIn2S4异质结微球催化剂重复使用四次,其催化能力依然保持较高水平。In2S3/CdIn2S4异质结微球活性的增强归因于异质结的形成有助于电子的转移,从而降低了电子空穴对的复合概率。并且合适的能带结构有助于产生大量的光生电子,电子与活性氧的结合最终引起氧化能力的增强。  相似文献   

6.
具有较高过电势的阳极析氧反应(OER)是电解水的关键半反应。利用理论过电势为0.37 V的尿素氧化反应(UOR)来降低阳极反应过电势。采用水热法在泡沫镍(NF)基底上原位构建NF@Ni3S4后,利用电化学沉积的方法在NF@Ni3S4表面生长Co Fe-LDHs,得到异质核壳结构NF@Ni3S4@Co Fe-LDHs电极。在尿素辅助碱性析氧反应过程中,该电极的分级结构可加快对中间产物的吸附和质子的解吸速率。在浓度为1 mol/L KOH电解液中,该电极在283 mV的过电势下可驱动100 mA/cm2的电流密度,塔菲尔斜率为55.9 mV/dec。在浓度为0.10、0.33和0.50 mol/L尿素与1 mol/L KOH混合电解液中,该电极均仅需1.33 V vs.RHE电压即可获得10m A/cm2的电流密度。在0.33 mol/L尿素和1 mol/L KOH混合电解液中,该电极可稳定运行20 h。  相似文献   

7.
积极响应国家“碳中和”和“碳达峰”时代战略,满足社会对高素质毕业生的需求,结合科学研究前沿热点领域,本文设计并制备了Ni3S2/MoS2异质结催化剂及其碱性析氢反应(HER)性能评价的综合实验。实验以水热法合成Mo-Ni球形前驱体,经高温煅烧得到Ni3S2/MoS2异质结纳米球,通过控制钼源、镍源比例可控地合成了Ni3S2/MoS2-1和Ni3S2/MoS2-2,实现了对界面结构的控制和优化。本实验涉及多学科专业知识,并紧随科研前沿,有助于推动学科交叉和知识融合,期望改变传统化学实验与时代脱轨的现状,激发学生学习热情,提高学生综合素质。  相似文献   

8.
随着原油储量的急剧下降,急需将重质原料转化为轻质油品以缓解原油的供应压力。浆态床加氢是一种可以将重质原料高效转化的先进技术,其核心难题在于开发高活性的加氢催化剂。采用葡萄糖和麦芽糖为碳源一步水热法合成MoS2/C纳米催化剂,并采用XRD、Raman、元素分析、SEM和HRTEM等方法表征催化剂的组成和结构。表征结果表明,MoS2/C催化剂由MoS2-C-MoS2碳插层结构的纳米片组成,纳米片具有层间距大、侧边尺寸小且堆积层数少的结构特点。以菲为重油模型化合物评价MoS2/C催化剂的加氢性能。结果表明,以葡萄糖为碳源且原料C/Mo原子比为5时制备的MoS2/C-G-5催化剂具有优异的催化加氢活性。该催化剂的菲加氢转化率高达85.6%,加氢率37.4%,深度加氢产物八氢菲选择性56.4%,分别是不加碳源制备的MoS2催化剂的1.6、2.4和2.3倍。MoS2/C催化剂的MoS2-C-MoS  相似文献   

9.
用S2O2-8 浸渍铁锆复合氧化物制得固体酸催化剂S2O2-8/Fe2O3-ZrO2(PSFZ),得到了较佳的制备条件,用马来酸酐与正己醇的酯化反应考察了催化剂的活性.通过XRD和TEM分析,对催化剂的结构进行了表征.结果表明,PSFZ的催化活性比SO2-4 /Fe2O3-ZrO2更强;S2O2-8对Fe2O3-ZrO2的促进作用明显高于SO2-4;铁的引入减少了ZrO2的团聚,增加了分散效果;有较好的使用重复性;它代替硫酸、对甲苯磺酸用于催化马来酸酐和正己醇的酯化反应可得无色透明的酯化产物.  相似文献   

10.
《化学试剂》2021,43(11):1480-1485
采用简单、可控的阳离子交换法和水热法在导电基底上成功构筑了具有自支撑纳米片阵列结构的Co_9S_8/Ni_3S_2电催化剂,在碱性电解液(1 mol/L KOH)中,采用三电极体系分别研究了Co_9S_8/Ni_3S_2的电催化析氧和析氢性能。在析氧性能测试中,Co_9S_8/Ni_3S_2/NF电催化剂获取50、100 mA/cm~2的催化电流密度所需要的过电位仅为230、280 mV。而在析氢性能测试中,Co_9S_8/Ni_3S_2/NF电催化剂获取-100 mA/cm~2的催化析氢电流密度所需的过电位仅为129 mV,同时该催化剂表现出了优异的电催化稳定性,其优异的电催化性能归因于其自支撑纳米片阵列结构,可提供更多的活性位点。  相似文献   

11.
    
A low-cost and high-activity catalyst for oxygen evolution reaction (OER) is the key to the water splitting technology for hydrogen generation. Here we report the use of three solvents, DMF, ethanol and glycol, in the solvothermal synthesis of three nano-catalysts, Co3(VO4)2-I, Co3(VO4)2-II, and Co3(VO4)2-III, respectively. Transmission electron microscope shows Co3(VO4)2-I, II, and III exist as ultrafine nanosheets, ultrathin nanofilms, and ultrafine nanosheet-comprised microspheres, respectively. These Co3(VO4)2 catalysts exhibit OER electrocatalysis, among which the Co3(VO4)2-II shows the lowest onset overpotential of 310 mVand only requires a small overpotential of 330 mV to drive current density of 10 mA/cm2. Due to their high surface free energy, the ultrathin nanofilms of Co3(VO4)2-II exhibits a good immobilization effect with the high electrocatalytic activity for OER.
  相似文献   

12.
开发用于水分解的高效稳定、低成本非贵金属电催化剂,特别是在同一电解质中对阴极的析氢反应(HER)和阳极的析氧反应(OER)都具有高效作用的电催化剂是一项挑战。以六水合硝酸钴、尿素、氟化铵和硒粉为原料,采用水热和高温固相法在镍网上原位构筑了CoSe2@NF,采用XRD、XPS、SEM和TEM对CoSe2@NF进行物相分析和形貌表征,并在碱性电解液中对CoSe2@NF的电催化析氧和析氢性能进行了测试。结果表明,表面粗糙的串珠状纳米线结构极大地增加了CoSe2有效活性位点的数量。该催化电极在OER和HER中均表现出高而稳定的催化活性。将CoSe2@NF作为全解水槽的阴阳极,在1.6 V槽电压下即可产生10 mA/cm2的电流,并可在1.7 V的电压下稳定运行100 h。这项研究为全解水提供了一种经济有效的解决方案.  相似文献   

13.
    
Magnetically recyclable Ni(Co)‐promoted MoS2 catalysts with greigite (G) core were synthesized and their activity and selectivity in hydrodeoxygenation of stearic acid were investigated. The activity of the catalysts tested at 320 °C and H2 initial pressure of 3.5 MPa could be ranked as NiMo/G > CoMo/G > Mo/G. Two main products were detected, C18 (through HDO pathway) and C17 hydrocarbons (through DCO pathway). HDO was the dominant pathway for all of the catalysts. As for the C18/C17 ratio, the catalysts were found to be in the order: Mo/G > CoMo/G ≈ NiMo/G. The Paraffin/Olefin ratio was over 1 for all of the catalysts with NiMo/G showing the highest ratio. Stearic acid was found to have an inhibiting effect on the adsorption of intermediates over the active sites. Moreover, the concentrations of intermediates decreased at high conversions of stearic acid. The formation of the intermediate aldehyde is through C–O hydrogenolysis of the fatty acid following the protonation, dehydrogenation, and hydride addition steps. The same steps were suggested to be involved in the transformation of the aldehyde to the alcohol. Formation of Cn‐1 hydrocarbons was found to be via decarbonylation route. The enhancement of the DCO pathway over the promoted catalysts was related to the electron transfer from the promoting atom to an adjacent sulphur atom and reduction in sulphur‐metal bond strength.  相似文献   

14.
《Ceramics International》2023,49(4):5646-5656
It is not an easy way to design composite electrodes with a high concentration of the constituent. This study cleverly exploited the phase transformation of molybdenum oxide to synthesize three-dimensional carbon-based endogenous-exogenous MoO2 composites (EEC) by a two-step process. MC-15 exhibited the most outstanding electrochemical performance among EEC, with a specific capacitance up to 411.1 F g?1 in Na2SO4, due to the design of MoO2, which could be highly loaded with three-dimensional carbon. In addition, the electrode capacitance remains up to 94.1% after 5000 cycles, attributed to the synergy effect of three-dimensional carbon and molybdenum dioxide by providing an abundance of active sites for MoO2 and overcoming its stacking. In this way, the electrochemical properties of the EEC electrode are not compromised by the volume expansion during the electrochemical process. The energy density of the asymmetric supercapacitor using this material as the negative electrode and MnO2@CC is 14 W h kg?1 at a power density of 802 W kg?1, showing a significant increase in energy density over the asymmetric supercapacitor with a conventional negative electrode (activated carbon, energy density of 3.36 W h kg?1 and power density of 700 W kg?1). Its specific capacitance remained 84.9% after 2500 cycles. In addition, an overpotential of only 348 mV was required to drive oxygen evolution in alkaline electrolytes with a Tafel slope as low as 88.7 mV dec?1; the 20 h stability test retains almost 100%. The results show that the design optimization of the negative electrode material provides a simple and effective strategy to increase the energy density of supercapacitors, and EEC electrode materials are a great candidate to be utilized in supercapacitors with excellent performance as well as electrolytic water.  相似文献   

15.
    
Electrochemical water splitting is an efficient and clean strategy to produce sustainable energy productions (especially hydrogen) from earth-abundant water. Recently, layered double hydroxide (LDH)-based materials have gained increasing attentions as promising electrocatalysts for water splitting. Designing LDHs into hierarchical architectures (e.g., core-shell nanoarrays) is one of the most promising strategies to improve their electrocatalytic performances, owing to the abundant exposure of active sites. This review mainly focuses on recent progress on the synthesis of hierarchical LDH-based core-shell nanoarrays as high performance electrocatalysts for electrochemical water splitting. By classifying different nanostructured materials combined with LDHs, a number of LDH-based core-shell nanoarrays have been developed and their synthesis strategies, structural characters and electrochemical performances are rationally described. Moreover, further developments and challenges in developing promising electrocatalysts based on hierarchical nanostructured LDHs are covered from the viewpoint of fundamental research and practical applications.  相似文献   

16.
氯化(8S,9R)-(-)-N-苄基辛可尼定的合成   总被引:1,自引:0,他引:1  
代星  覃兆海  王明安 《化学试剂》2001,23(2):109-109,114
等摩尔的苄氯与辛可尼定在无水乙醇中回流2-4h,即可得到氯化(8S,9R)-(-)-N-苄基辛可尼定,产率为60%,e,e.值为>99%。  相似文献   

17.
以六水合硝酸钴、六水合硝酸镍、尿素和氟化铵为原料,采用水热法在镍网上原位构筑层状双金属氢氧化物(LDH)(CoNi-LDH@NF),然后采用快速界面法在硝酸钠和六水合氯化铁的100℃溶液中对其进行刻蚀制备了FeOOH@CoNi-LDH@NF.利用XRD、SEM、XPS和TEM对FeOOH@CoNi-LDH@NF进行了形...  相似文献   

18.
采用水热法分别合成杂多酸H6P2Mo9W9O62及有机金属骨架Zn(BDC) (Bipy)0.5,使用浸渍法合成H6P2Mo9W9O62/Zn(BDC) (Bipy)05复合材料,用该复合材料催化醛、乙酰乙酸乙酯和尿素通过Biginelli反应,乙醇作溶剂,合成6种3,4-二氢嘧啶-2(H)酮衍生物.通过IR、1HNMR、13CNMR确定其结构,通过m.p.确定其纯度.实验结果表明:固定醛用量为0.04 mol,n(醛)∶n(乙酰乙酸乙酯)∶n(尿素)=1∶1.4∶1.5,2.0 wt% H6P2Mo9W9O62/Zn(BDC)(Bipy)0.5,反应温度为105℃,反应时间为60 min时,产物收率为40.1%~91.5%.  相似文献   

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