共查询到20条相似文献,搜索用时 62 毫秒
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采用细乳液聚合法制备了聚丙烯腈(PAN)微球,以其作为氮掺杂多孔碳材料(NPC)的前驱体,经ZnCl_2溶液浸渍后,分别在450℃、600℃和700℃这3个不同温度下碳化制得多孔碳材料NPC-H450、NPC-H600和NPCH700。采用透射电镜(TEM)、X射线光电子能谱(XPS)和N_2吸附-脱附等方法对样品进行表征。研究了NPC对CO_2和Cu~(2+)的吸附性能。结果表明:所制备的多孔碳材料NPC-H450、NPC-H600和NPC-H700的比表面积大,分别为1114m~2/g、1644m~2/g和931m~2/g;氮含量高,质量分数分别为11.33%、12.12%和13.35%。制备的NPC对CO_2及Cu~(2+)均有良好吸附的性能。在0℃、1atm条件下,NPC-H450对CO_2的吸附量为3.40mmol/g,NPC-H700在常温下对Cu~(2+)24h的吸附量可达62.88mg/g。 相似文献
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碳化钨(WC)是高成本和资源稀缺铂基催化剂的优良替代品.以偏钨酸铵(AMT)、葡萄糖(C6H12O6)和二氰二胺(DCDA)为W、C和N源,采用简易的NaCl/KCl熔融盐一步碳化法制备碳负载氮(N)掺杂WC@NC纳米晶粒.利用XRD、SEM、TEM、XPS、电化学工作站对催化剂的物相、形貌及电催化析氢性能进行表征.结果表明,WC@NC由碳片和WC组成,颗粒分布均匀,纳米颗粒平均直径为10~30 nm.WC@NC在0.5 mol/L H2SO4电解液中电流密度为10mA/cm2的过电位是132mV,塔菲尔斜率为64.2mV/dec.经过5000次循环伏安测试和25h持续电解析氢测试后,线性扫描伏安(LSV)曲线和电流密度均无明显变化,表现出非常高的稳定性. 相似文献
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Majid Shaker Ali Asghar Sadeghi Ghazvini Taieb Shahalizade Mehran Ali Gaho Asim Mumtaz Shayan Javanmardi Reza Riahifar MENG Xiao-min JIN Zhan GE Qi 《新型炭材料》2023,(2):247-282
硬碳、活性炭、碳纳米管(CNTs)、石墨烯、多孔炭和炭纤维等炭材料替代锂离子电池的石墨阳极是目前的研究热点。与石墨相比,这种材料已表现出更好的储锂电化学性能,但仍有待进一步发展空间。其中一种有效的方法是在炭材料结构中加入杂原子(例如氮),提高其作为锂离子负极时的电化学性能。本综述首先描述了氮掺杂如何对锂离子电池的性能产生积极影响,并举例说明了氮掺杂炭材料的优势。然后,比较了不同N掺杂炭材料中的X射线光电子能谱和扫描隧道显微镜的表征结果,通过统计分析了掺氮量对掺氮碳材料比容量的影响。 相似文献
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Thermally Stable Metal‐Organic Framework‐Templated Synthesis of Hierarchically Porous Metal Sulfides: Enhanced Photocatalytic Hydrogen Production 下载免费PDF全文
Porous nanostructured materials are demonstrated to be very promising in catalysis due to their well accessible active sites. Thermally stable metal‐organic frameworks (MOFs) as hard templates are successfully utilized to afford porous metal oxides and subsequently metal sulfides by a nanocasting method. The resultant metal oxides/sulfides show considerable Brunauer–Emmett–Teller (BET) surface areas, by partially inheriting the pore character of MOF templates. Preliminary investigation on the obtained hierarchically porous CdS for water splitting, as a proof of concept, demonstrates its much higher activity than both corresponding bulk and nanosized counterparts, under visible light irradiation. Given the structural diversity and tailorability of MOFs, such synthetic approach may open an avenue to the synthesis of advanced porous materials for functional applications. 相似文献
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以碳纳米管(CNTs)为基础材料,聚甲基丙烯酸甲酯(PMMA)为造孔剂,构筑多孔结构,并将水解反应所得的氧化锌/锌复合纳米颗粒附着在孔隙结构中,制得氧化锌/锌/碳纳米管多孔复合结构,氧化锌纳米棒直径约30~60nm,长径比可达40。对复合结构的微观结构及成分表征显示,制备ZnO/Zn/CNT多孔复合结构的过程中,无杂质生成,氧化锌晶体结构也没有发生变化。多孔复合结构对模拟污染物的暗室催化降解研究结果显示,复合结构催化降解亚甲基蓝时起主要作用的是ZnO纳米棒,在多孔结构中受力变形产生电子空穴对,在无光条件下降解有机污染物,且孔径越大、水流冲击力越强,对亚甲基蓝的催化降解效果越好。 相似文献
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电极材料的性能决定超级电容器的储能特性,因此研究优异电极材料的制备方法是提高其储能特性的重要前提。多孔石墨烯(Porous graphene)作为新型的碳材料具有比表面积大、电导率高等优点,是一种理想的双电层电容器电极材料。本工作制备的多孔石墨烯材料微孔和中孔都很发达,孔径分布更为合理,因此其比表面积相较于原始的石墨烯有了很大的提高。经检测该材料的比表面积为1 417.65 m2·g-1,并且能够提供较高的电化学双电层电容,经测试由该材料组装成的扣式超级电容具有31.7 F·g-1的比容量且具有优良的导电特性。此外,在电流密度1 A·g-1下循环10 000次后材料比电容保持率为78%。这些电化学测试结果表明本研究制备的多孔石墨烯在超级电容器的能量存储方面具有较好的应用前景。 相似文献
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以沥青基炭纤维为原料,用水蒸气活化的方法制备了三种不同比表面积的活性炭纤维,并采用氮吸附法和拉曼光谱对活性炭纤维进行了表征。本文研究了活性炭纤维在常温下对模拟空气中50 ppm NO的催化氧化性能,结果表明,活性炭纤维可将NO部分催化转化为NO2,较低比表面积的活性炭纤维因为其较窄的孔径分布和较大的类石墨微晶有利于对NO的催化氧化。 相似文献
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金属酞菁负载纤维对空气中含硫化合物的催化氧化 总被引:6,自引:0,他引:6
合成了八羧基钴酞菁(Co-oaPc)和八羧基铁酞菁(Fe-oaPc) 两种水溶性酞菁,将这两种酞菁及两者按摩尔比为1:1混合的酞菁分别负载到阳离子改性的粘胶纤维上,制得3种金属酞菁负载纤维.测试其在溶液中对巯基乙醇的催化氧化性能发现这些负载纤维均具有催化氧化能力,而混合金属酞菁负载纤维的催化活性最高;通过在空气中对甲硫醇和H2S的消除实验,得到的结论相同.ESR测试表明,混合酞菁负载纤维可以观测到10个Co2 和Fe3 的超精细分裂线,表明其聚集的趋势较两种酞菁单独负载时弱,有利于甲硫醇和硫化氢分子与酞菁发生轴向配位,从而提高其催化活性. 相似文献
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Green Synthesis of Hierarchically Porous Carbon Nanotubes as Advanced Materials for High‐Efficient Energy Storage 下载免费PDF全文
Jian‐Gan Wang Hongzhen Liu Xingyuan Zhang Xu Li Xingrui Liu Feiyu Kang 《Small (Weinheim an der Bergstrasse, Germany)》2018,14(13)
Hierarchically porous carbon nanomaterials with well‐defined architecture can afford a promising platform for effectively addressing energy and environmental concerns. Herein, a totally green and straightforward synthesis strategy for the fabrication of hierarchically porous carbon nanotubes (HPCNTs) by a simple carbonization treatment without any assistance of soft/hard templates and activation procedures is demonstrated. A high specific surface area of 1419 m2 g?1 and hierarchical micro‐/meso‐/macroporosity can be achieved for the HPCNTs. The unique porous architecture enables the HPCNTs serving as excellent electrode/host materials for high‐performance supercapacitors and Li–sulfur batteries. The design strategy may pave a new avenue for the rational synthesis of hierarchically porous carbon nanostructures for high‐efficient energy storage applications. 相似文献
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Facile Synthesis of Porous Pd3Pt Half‐Shells with Rich “Active Sites” as Efficient Catalysts for Formic Acid Oxidation 下载免费PDF全文
Xiaoxiao Yan Xuejiao Hu Gengtao Fu Lin Xu Jong‐Min Lee Yawen Tang 《Small (Weinheim an der Bergstrasse, Germany)》2018,14(13)
Exploring highly efficient electrocatalysts is greatly important for the widespread uptake of the fuel cells. However, many newly generated nanocrystals with attractive nanostructures often have extremely limited surface area or large particle‐size, which leads them to display limited electrocatalytic performance. Herein, a novel anode catalyst of hollow and porous Pd3Pt half‐shells with rich “active sites” is synthesized by using urea as a guiding surfactant. It is identified that the formation of Pd3Pt half‐shells involves the combination of bubble guiding, in situ deposition of particles and bubble burst. The obtained Pd3Pt half‐shells demonstrate a rich edge area with abundant exposed active sites and surface defects, indicating great potential for the electrocatalysis. When used as an electrocatalyst, the Pd3Pt half‐shells exhibit remarkably improved electrocatalytic performance for formic acid oxidation (FAO), where it promotes the dehydrogenation process of FAO by suppressing the formation of poisonous species COads via the electronic effect and ensemble effect. 相似文献