Pd-NPs@alkyne-PVA/GO复合材料制备及其电催化析氢性能

开发高效、稳定的电催化剂是实现电解水制氢反应(HER)的关键。成功制备以炔基化的聚乙烯醇(alkyne-PVA)改性的单层氧化石墨烯(GO)载体,以硼氢化钠为还原剂,将钯纳米颗粒(Pd-NPs)负载在碳基材料上,合成Pd-NPs@alkyne-PVA/GO复合材料。通过SEM、TEM、XRD、N2吸附-脱附和XPS对所合成物质的形貌、结构、比表面积及孔径进行分析;采用电化学工作站测试催化剂的线性扫描伏安曲线(LSV)和Tafel斜率,分析所合成催化剂的电催化析氢性能。结果表明Pd-NPs@alkyne-PVA/GO复合材料在酸性电解质中的电催化性能较好,其在电流密度为-10 mA·cm^-2时,过电位仅为-80 mV。     

复合材料修饰电极电催化析氢的研究进展

近年来,空气污染,水污染,以及资源短缺等问题受到人们广泛关注。现如今,化学领域最主要的研究课题就是“绿色化学”。氢气是公认的最干净的能源之一,制取成本不高,并且利用现如今的科学手段可以有效地进行保存。氢气燃烧产物是水,没有毒害,并且它的能量利用率和效率非常高。电解水制备氢气是较实用的一种方法,催化剂就是必不可少的。本文章介绍了复合材料修饰电极电催化析氢的应用及研究进展,并对今后研究方向提出展望。     

银纳米粒子的制备及其电催化析氢的研究

通过低温水热法制备了银纳米粒子。分别采用X射线衍射、扫描电子显微镜和透射电子显微镜对银纳米粒子的结构和尺寸进行了表征,结果显示银纳米粒子为立方晶相,尺寸约为70 nm,其表面展现出棱边但不是规则的立体形貌。将银纳米粒子用于电催化析氢性能测试,结果表明,纳米银在酸性条件下对析氢反应表现出一定的催化活性和稳定性,在10 m A/cm2电流密度下的过电位比块体银小100 m V,且塔菲尔斜率比块体银的小13 m V/dec。     

电催化析氢催化剂研究进展

氢能热值高和环境友好性强等特点使其成为未来能源界最具发展潜力的能源之一。电催化析氢反应（hydrogen evolution reaction,HER）作为一种绿色、可持续的产氢方法成为近年来广泛研究的主题。发展高性能、低成本、高活性的析氢催化剂是目前该领域面临的主要挑战。本文总结了近年来高性能催化剂用于HER反应的进展,重点介绍HER反应的基本原理,评估HER催化剂催化性能的典型方法,过渡金属以及化合物、非金属催化剂以及单原子催化剂等电催化析氢催化剂的最新研究进展,系统讨论了催化活性与催化剂形态、结构、组成和合成方法之间的联系,并对催化剂的合成策略、活性位点的固有活性、如何提高活性中心的内在活性和活性位点的数量进行了展望。     

低Pt载量PtFeNi@C催化剂制备及其电解水析氢性能

开发低成本、高性能的贵金属Pt基电催化剂对于电解水制氢反应(HER)具有重要意义。采用“双溶剂”(正己烷为分散剂,水为溶剂)策略,以棒状双金属FeNi-MOFs为前体,将H₂PtCl₆浸渍到双金属FeNi-MOFs孔道内,在Ar氛围600℃煅烧2 h得到PtFeNi@C复合催化材料,采用SEM、TEM、XRD和XPS对所合成材料的形貌、结构进行分析;采用电化学工作站测试催化剂的线性扫描伏安曲线(LSV)和Tafel斜率,研究合成材料的HER性能。结果表明PtFeNi@C催化剂在0.5 mol/L硫酸电解质中的电催化性能较好,电流密度为-10 mA·cm^-2时,过电位仅为-42 mV。     

配位负载法制备CoS2/AOCF复合材料及其电催化析氢性能

以硫酸钴、硫代硫酸钠、硫和偕胺肟化聚丙烯腈纤维(AOCF)为原料,采用配位负载法制备了CoS2/AOCF复合材料,采用SEM、XRD、TEM、XPS和BET对CoS2/AOCF进行物相分析和形貌表征,并对CoS2/AOCF复合材料的电催化析氢性能进行了测试.结果表明,AOCF链上—OH、—NH2与Co(Ⅱ)的配位作用极...     

RuCs/Mo2C纳米棒制备及电催化析氢的研究

Mo₂C被誉为最有前景的电催化产氢催化剂,然而其高的过电压和低效率限制了其规模化生产。本文通过简单的溶剂热法制备了Ru纳米簇(Ru Cs/Mo₂C)负载Mo₂C纳米棒复合材料。研究表明,Ru Cs/Mo₂C(Ru,质量分数7.79%)表现出优异的电催化产氢性能,电流密度在10 mA·cm^-2的过电势为104 mV,Tafel斜率为96.30 mV·dec^-1。同时,Ru Cs/Mo₂C催化剂具有优异的稳定性,在工业电解系统中具有广阔的应用前景。     

Ni/CrN高效电催化剂的制备及其析氢催化性能

氢能是一种具有高能量密度的清洁能源,如何有效的开发绿氢技术是当前社会首要解决的问题,而研发高效稳定的电解水产氢技术的电催化剂是一种可行性的方式,对促进氢能经济的发展具有重要的意义。通过水热-高温热解两步法合成了一种氮化铬支撑镍纳米颗粒的催化剂(Ni/CrN)。利用XRD、XPS、SEM以及TEM等测试手段对催化剂的形貌及结构进行表征,并在碱性环境下对催化剂进行电催化析氢性能的研究。结果表明,Ni/CrN形成了具有珊瑚状的微观结构,优化了电子结构,并且表现出了优异的析氢反应(HER)催化性能,在10 mA/cm²的电流密度下,Ni/CrN催化剂仅有66 mV的过电位和47 mV/dec的Tafel斜率,十分接近商业的Pt/C催化剂的析氢性能。在10 mA/cm²电流密度的循环稳定性测试中,Ni/CrN表现出比商业Pt/C电极更优越的催化稳定性。     

配位负载法制备CoS2/AOCF复合材料及电催化析氢性能

以硫酸钴、硫代硫酸钠、硫和偕胺肟化聚丙烯腈纤维(AOCF)为原料，采用配位负载法制备了CoS2/AOCF复合材料，通过设计偕胺肟化聚丙烯腈高分子链上的—OH和—NH2基团与Co(Ⅱ)配位作用，极大提高了活性组分CoS2的比表面积，改变了活性组分的晶体结构，增大了有效活性位点的数量。采用SEM、XRD、TEM、XPS和BET对CoS2/AOCF进行物相分析和形貌表征，并对CoS2/AOCF复合材料进行电催化析氢性能测试。结果表明：CoS2/AOCF在10 mA/cm2的电流密度下过电势为92 mV，Tafel斜率仅为43 mV/dec，具有良好的析氢稳定性，展现了优异的电化学性能。     

CNTs/Ni-W/CC复合电极的构筑及电解水析氢催化性能

在碳布材料(CC)表面首先电沉积W原子分数约为13％的Ni-W合金,再通过化学气相沉积(CVD)在其表面生长碳纳米管(CNTs),构筑出一种自支撑CNTs/Ni-W/CC复合电极.电化学测试表明:该复合电极在1 mol/L NaOH水溶液中表现出良好的电解水析氢(HER)催化性能.在不同温度下保温2 h所获样品中,90...     

Polypyrrole@NiCo hybrid nanotube arrays as high performance electrocatalyst for hydrogen evolution reaction in alkaline solution

The polypyrrole(PPy)@NiCo hybrid nanotube arrays have been successfully fabricated as a high performance electrocatalyst for hydrogen evolution reaction (HER) in alkaline solution. The strong electronic interactions between PPy and NiCo alloy are confirmed by X-ray photoelectron spectroscopy and Raman spectra. Because these interations can remarkably reduce the apparent activation energy (E_a) for HER and enhance the turnover frequency of catalysts, the electrocatalytic performance of PPy@NiCo hybrid nanotube arrays are significantly improved. The electrochemical tests show that the PPy@NiCo hybrid catalysts exhibit a low overpotential of ~186 mV at 10.0 mA·cm^–2 and a small tafel slope of 88.6 mV·deg^–1 for HER in the alkaline solution. The PPy@NiCo hybrid nanotubes also exhibit high catalytic activity and high stability for HER.

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钯复合膜的制备及其在氢气氮气分离中的应用

Thin palladium composite membranes were prepared by modified electroless plating method on a-alumina supports and a dense Pd/α-Al2O3 composite membrane with high hydrogen flux, good selectivity for hydrogen was obtained. It was tested in a single gas permeation system for hydrogen permeance and hydrogen selectivity over mtrogen. The hydrogen permeance of the corresponding membrane was ashigh as 2.45×10^-6mol·m^-2·s^-1.Pa^-1 and H2/N2 selectivityover700 at 623K and a pressure difference of 0.1MPa. The-main resistance of the composite membrane to H2 permeation lies in the aluminum ceramic support rather than the thin Pd layer.     

聚苯胺/二氧化锰复合材料的制备及其光催化性能

以二氧化锰为模板,采用原位复合法合成聚苯胺/二氧化锰复合材料(PANI/Mn O2)。采用IR和XRD对产物进行表征,结果表明,复合材料中的聚苯胺是理想的翠绿亚胺结构,二氧化锰为四方晶系α-Mn O2。研究光催化剂用量、染料浓度和催化剂重复使用次数对光催化降解直接耐晒翠蓝的影响,结果表明,在染料直接耐晒翠蓝浓度10 mg·L-1、PANI/Mn O2催化剂用量0.010 g·(20 m L)-1和光照20 min条件下,直接耐晒翠蓝降解率达84.1%。     

非晶态硼化物Ni-Fe-Co-B的合成及电催化析氧性能

电解水制氢是绿色氢能源研究中的热点课题。其中，析氧半反应较高的过电位是导致电解水动力学缓慢的主要原因。为了提高电解水制氢的效率，本文主要通过简单的液相合成方法，以硼氢化钠和过渡金属Ni，Fe，Co盐为原料，制备了非晶态的过渡金属硼化物Ni-Fe-Co-B，将其作为析氧半反应催化剂。对Ni-Fe-Co-B进行了SEM、TEM、XRD、XPS和电化学表征。结果表明，非晶态催化材料Ni-Fe-Co-B被成功合成，当n(Ni)∶n(Fe)∶n(Co)=1∶1∶1，电流密度为20 mA/cm2时，Ni-Fe-Co-B的过电位仅为299 mV，Tafel斜率为101 mV/dec。在0.47 V的恒电压测试下，Ni-Fe-Co-B具有12h以上的稳定性。     

The electrochemical and electrocatalytic behaviour of glassy metals

The suitability of a selection of amorphous alloys as electrocatalysts or as inhibitors for hydrogen evolution (HE) was investigated in 1 m KOH at 25 °C. Mild basic conditions were chosen so as to make direct comparison with other data, where available. The alloys studied were the known glassy alloys Fe₆₇Co₁₈B₁₄Si₁, Co₆₆Fe₄Si₁₆B₁₂Mo₂, Fe₄₀Ni₄₀B₂₀ and Fe₄₀Ni₄₀P₁₄B₆ and an entirely new glassy alloy Zr_73.22Ti_19.71Cu_1.24Fe_5.83. The electrochemical techniques of slow sweep anodic and cathodic polarisation were used, in conjunction with the surface analysis techniques of scanning electron microscopy (SEM) and X-ray analysis, to characterise the alloys and new data has been obtained for all alloys. The glassy alloys were tested in their as-polished state, as well as after surface activation, by ex situ chemical (acid etching) and in situ electrochemical (anodic oxidation in base) pre-treatment. The least corrosion resistant composition, Fe₆₇Co₁₈B₁₄Si₁, displayed the highest activity for HE in the as-polished state and only a minor improvement resulted from surface pre-treatment. Corrosion resistance was partly characterised by the degree to which the passive region increased and the passive region current decreased as a function of pre-treatment. The most corrosion resistant alloy, Zr_73.22Ti_19.71Cu_1.24Fe_5.83, displayed the poorest activity for HE in the as-polished state, but a significant improvement resulted from surface activation by in situ anodic oxidation in basic media. Surface activation by acid pre-treatment reduced the corrosion resistance of the Zr_73.22Ti_19.71 Cu_1.24Fe_5.83 alloy and was, therefore, a non-viable and destructive procedure. However, acid pre-treatment was effective in substantially activating the glassy Co₆₆Fe₄Si₁₆B₁₂Mo₂ and Fe₄₀Ni₄₀P₁₄B₆ alloys towards HE and did not alter the corrosion properties of these compositions. A novel technique for mounting thin alloy specimens has been developed, using an insulating photo-resist coating, resulting in sharply defined electrode edges.     

脉冲和直流电沉积Ni-P合金电极析氢电催化性能的研究

在由250 g/L NiSO4·6H2O、45 g/L NiCl2·6H2O、36 g/LH3BO3、20 g/L NaH2PO2·H2O和0.05～0.10 g/L十二烷基硫酸钠组成的镀液(pH 4.0～5.5)中,分别用脉冲和直流电沉积法在镍片上获得了Ni-P合金镀层,并进行了对比研究,SEM测试结果表明,脉冲电沉积方法获得的Ni-P合金镀层表面更加细致,电化学测试结果表明,脉冲电沉积镀层的交换电流密度较大,具有良好的析氢电催化活性,优良的电化学稳定性和良好的结合力及耐蚀性.     

Interface engineering for enhancing electrocatalytic oxygen evolution reaction of CoS/CeO2 heterostructures

To realize renewable energy conversion,it is important to develop low-cost and high-efficiency electrocatalyst for oxygen evolution reaction.In this communication,a novel bijunction CoS/CeO₂ electrocatalyst grown on carbon cloth is prepared by the interface engineering.The interface engineering of CoS and CeO₂ facilitates a rapid charge transfer from CeO₂ to CoS.Such an electrocatalyst exhibits outstanding electrocatalytic activity with a low overpotential of 311 mV at 10 mA·cm?2 and low Tafel slope of 76.2 mV·dec?1,and is superior to that of CoS(372 mV)and CeO₂(530 mV)counterparts.And it has long-term durability under alkaline media.     

电沉积Ni-P-ZrO2复合电极析氢电催化性能的研究

用电沉积方法制备了镍－磷－二氧化锆复合电极。通过阴极极化曲线,交流阻抗等电化学技术研究其析氢催化性能,并用扫描电镜观察电极的表面形貌。实验结果表明,在80℃,25％氢氧化钠碱性溶液中镍－磷－二氧化锆的表观交换电流密度及表面粗糙度皆大于镍,镍－磷电极,而反应电阻较小。说明镍－磷中引入二氧化锆所形成的复合镀层具有较高的析氢催化活性和良好的电化学稳定性。