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愈创木酚法快速筛选漆酶产生菌 被引量:35
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作者 王宜磊 朱陶 邓振旭 《生物技术》 CAS CSCD 2007年第2期40-42,共3页
目的:寻找漆酶产生菌实用、简便的筛选方法,以提高筛选的效率。方法:用6个不同浓度的9种试剂,在3种不同的固体培养基上对23株真菌进行了试验研究,并将其所形成的氧化带与液体发酵培养产生漆酶的活力进行了比较。结果:愈创木酚作底物... 目的:寻找漆酶产生菌实用、简便的筛选方法,以提高筛选的效率。方法:用6个不同浓度的9种试剂,在3种不同的固体培养基上对23株真菌进行了试验研究,并将其所形成的氧化带与液体发酵培养产生漆酶的活力进行了比较。结果:愈创木酚作底物能形成鲜艳而均匀的红棕色氧化带,且其颜色深浅、带宽能较好地反应漆酶活性。结论:含有0.04%愈创木酚的PDA培养基,在48-72h内产生的氧化带与漆酶活力有明显的相关性,此法能快速筛选产生漆酶的菌株。 展开更多
关键词 漆酶 愈创木酚 初筛 氧化带 真菌
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漆酶产生菌初筛条件的优化研究 被引量:8
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作者 王宜磊 朱陶 《唐山师范学院学报》 2003年第2期26-27,81,共3页
运用不同底物,不同浓度,不同基础培养基进行了漆酶产生菌初筛条件的优化,找到了愈创木酚、邻联甲苯胺、联苯胺三种较好的底物,及其他们的最适使用浓度和最佳观察时间。
关键词 愈创木酚 邻联甲苯胺 联苯胺 漆酶 初筛 氧化带 毛栓菌 多酚氧化酶 菌株 优化 培养基
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力竭运动诱导的氧化应激对大鼠红细胞Band 3蛋白的影响及其机制探讨 被引量:6
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作者 熊延连 熊艳蕾 +3 位作者 李遥金 唐福州 赵押金 王翔 《中国细胞生物学学报》 CAS CSCD 北大核心 2014年第5期617-623,共7页
为了探讨力竭运动诱导的氧化应激反应对大鼠红细胞Band 3蛋白的影响,该文以大鼠跑步运动为模型,对三种不同运动条件下(静坐组、适度运动组和力竭运动组)大鼠红细胞抗氧化能力和氧化损伤程度进行了检测,并对氧化应激反应诱导的红细胞膜Ba... 为了探讨力竭运动诱导的氧化应激反应对大鼠红细胞Band 3蛋白的影响,该文以大鼠跑步运动为模型,对三种不同运动条件下(静坐组、适度运动组和力竭运动组)大鼠红细胞抗氧化能力和氧化损伤程度进行了检测,并对氧化应激反应诱导的红细胞膜Band 3蛋白表达和分布情况及其调控的阴离子通道活性进行了分析。结果表明:力竭运动条件下大鼠红细胞受到严重的氧化应激损伤,红细胞内抗氧化能力下降;导致膜Band 3蛋白巯基交联为主的蛋白聚簇化反应及其阴离子转运能力的下降。Band 3蛋白的损伤将进一步诱导红细胞携氧和变形能力的下降,成为运动相关疾病的潜在致病因素。 展开更多
关键词 力竭运动 红细胞 氧化应激 band 3
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SYNTHESIS,CHARACTERIZATION,THERMAL DEGRADATION AND ELECTROCHEMICAL PROPERTIES OF OLIGO-4-m-TOLYLAZOMETHINEPHENOL
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作者 smet Kaya Yasin Bayrakli 《Chinese Journal of Polymer Science》 SCIE CAS CSCD 2006年第6期647-656,共10页
The oxidative polycondensation reaction conditions of 4-m-tolylazomethinephenol (4-TAMP) in the presence of air O2 and NaOCl as oxidants were studied in an aqueous alkaline medium between 50 and 90℃. The structures... The oxidative polycondensation reaction conditions of 4-m-tolylazomethinephenol (4-TAMP) in the presence of air O2 and NaOCl as oxidants were studied in an aqueous alkaline medium between 50 and 90℃. The structures of the obtained monomer and oligomer were confirmed by FT-IR, UV-Vis, ^1H- and ^13C-NMR and elemental analysis techniques. The physical characterization was made by TG-DTA, size exclusion chromatography (SEC) and solubility tests. At the optimum reaction conditions, the yield of oligo-4-m-tolylazomethinephenol (O-4-TAMP) was found to be 62.50% (for air O2 oxidant) and 90.0% (for NaOCl oxidant), respectively. According to the SEC analysis, the number-average molecular weight (Mn), weight-average molecular weight (Mw) and polydispersity index (PDI) values of O-4-TAMP were found to be 2310, 2610 g tool 1 and 1. 13, respectively, using air O2, and 1390, 1710 g mol^-1 and 1.23, using NaOCl, respectively. According to TG-DTA analyses, O-4-TAMP was more stable than 4-TAMP against thermal decomposition. The weight losses of 4-TAMP and O-4-TAMP were found to be 68% and 58% at 1000℃. Electrical conductivity of the O-4-TAMP was measured, showing that the polymer is a typical semiconductor. Electrochemically, the highest occupied molecular orbital (HOMO), the lowest unoccupied molecular orbital (LUMO) and electrochemical energy gaps (E'g) for 4-TAMP are -5.96, -3.22 and 2.74 eV, respectively. The HOMO, LUMO and (E'g) for O-4-TAMP are -5.78, -3.44 and 2.34 eV, respectively. According to UV-Vis measurements, optical band gaps (Eg) of 4-TAMP and O-4-TAMP were found to be 3.45 and 3. 1 0 eV, respectively. 展开更多
关键词 Air O2 NAOCL Oligo-4-m-tolylazomethinephenol oxidative polycondensation Thermal analysis band gap CONDUCTIVITY
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Selective and effective oxidation of 5-hydroxymethylfurfural by tuning the intermediates adsorption on Co-Cu-CN_(x) 被引量:1
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作者 Tianyun Jing Shaokang Yang +3 位作者 Yonghai Feng Tingting Li Yunpeng Zuo Dewei Rao 《Nano Research》 SCIE EI CSCD 2023年第5期6670-6678,共9页
Co-based catalysts are promising alternatives to precious metals for the selective and effective oxidation of 5-hydroxymethylfurfural(HMF)to the higher value-added 2,5-furandicarboxylic acid(FDCA).However,these cataly... Co-based catalysts are promising alternatives to precious metals for the selective and effective oxidation of 5-hydroxymethylfurfural(HMF)to the higher value-added 2,5-furandicarboxylic acid(FDCA).However,these catalysts still suffer from unsatisfactory activity and poor selectivity.A series of N-doped carbon-supported Co-based dual-metal nanoparticles(NPs)have been designed,among which the Co-Cu_(1.4)-CN_(x) exhibits enhanced HMF oxidative activity,achieving FDCA formation rates 4 times higher than that of pristine Co-CN_(x),with 100%FDCA selectivity.Density functional theory(DFT)calculations evidenced that the increased electron density on Co sites induced by Cu can mediate the positive electronegativity offset to downshift the dband center of Co-Cu_(1.4)-CN_(x),thus reducing the energy barriers for the conversion of HMF to FDCA.Such findings will support the development of superior non-precious metal catalysts for HMF oxidation. 展开更多
关键词 Co-based materials 5-hydroxymethylfurfural(HMF)oxidative activity 2 5-furandicarboxylic acid(FDCA)selectivity electronegativity offset d-band center
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采面供风量与采空区遗煤自燃危险性关系分析 被引量:20
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作者 徐精彩 王军 《西安矿业学院学报》 北大核心 1994年第3期195-199,共5页
根据实验得出的规律和测试的数据,结合采煤工作面能够实测和掌握的信息资料,推断采空区氧化带范围,进而判断采空区遗煤自燃危险程度。
关键词 供风量 矿山安全 内因火灾 采空区
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Constructing charge transfer channel between dopants and oxygen vacancies for enhanced visible-light-driven water oxidation 被引量:8
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作者 Ming Cheng Lan Yang +3 位作者 Huiyi Li Wei Bai Chong Xiao Yi Xie 《Nano Research》 SCIE EI CSCD 2021年第10期3365-3371,共7页
Photocatalytic water oxidation is a crucial step in water splitting,but is generally restricted by the slow kinetics.Therefore,it is necessary to develop high-performance water oxidation photocatalysts.Herein,the Fe-d... Photocatalytic water oxidation is a crucial step in water splitting,but is generally restricted by the slow kinetics.Therefore,it is necessary to develop high-performance water oxidation photocatalysts.Herein,the Fe-doped Bi2WO6 nanosheets with oxygen vacancies(OVs)were synthesized for enhanced photocatalytic water oxidation efficiency,showing a synergistic effect between Fe dopants and OVs.When a molar fraction of 2%Fe was doped into the Bi2WO6 nanosheets,the visible-light-driven photocatalytic oxygen evolution rate was increased up to 131.3μmol·h^(-1)·g_(cat)^(-1)under ambient conditions,which was more than 3 times that of pure Bi2WO6 nanosheets.The proper doping concentration of Fe could promote the formation of OVs and at the same time modulate the band structure of catalysts,especially the position of the valence band maximum(VBM),leading to effective visible-light absorption and enhanced oxidizing ability of photogenerated holes.With ameliorated localized electron distribution,fast charge transfer channel emerged between the OVs and adjacent metal atoms,which accelerated the charge carrier transfer and promoted the separation of photoexcited electrons and holes.This work provides feasible approaches for designing efficient two-dimensional semiconductor water oxidation photocatalysts that could utilize visible-light,which will make more use of solar energy. 展开更多
关键词 water oxidation reaction Bi2WO6 nanosheets oxygen vacancies valence band maximum charge transfer channel
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Effect of Rare Earth on Void Band of Diffusion Layer and Properties of Aluminized Steel 被引量:4
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作者 ZHANG Wei FAN Zhi-kang +3 位作者 HU Peng-fei LONG Yong-qiang LIU Hua WEN Jiu-ba 《Journal of Iron and Steel Research International》 SCIE EI CAS CSCD 2006年第5期60-64,78,共6页
The effects of the addition of rare earth (RE) elements on the void band in the diffusion layer, and the re sistances to both oxidation and spalling of aluminized steel were investigated through high temperature oxi... The effects of the addition of rare earth (RE) elements on the void band in the diffusion layer, and the re sistances to both oxidation and spalling of aluminized steel were investigated through high temperature oxidation and spalling tests. The results showed that RE had significant effects on the void band in the diffusion layer and the properties of aluminized steel. After diffusion treatment, a considerable number of the voids between the middle layer and transitional layer of pure aluminized coating, aggregated into wavy-line-shaped void bands parallel to the outer surface. For the RE added aluminized coating, only a few voids aggregated into intermittent block shapes. During high temperature oxidation at 800 ℃ for 200 h, the wavy void band of pure aluminized coating aggregated further into a linear crack parallel to the outer surface, and the internal oxidation occurred within them; the open cracks perpendicular to the surface penetrated through the diffusion layer. For the RE added aluminized coating, only a few voids aggregated into intermittent meniscus shapes. During cyclic spalling tests, the peeling, spallation, and pulver ulent cracking occurred along the void band in the diffusion layer of pure aluminized coating, but only a little spallation occurred in the diffusion layer of the RE-added aluminized coating, in which cracks perpendicular to the surface were much smaller than those of pure aluminized coating and did not penetrate through the diffusion layer. It is evident that RE addition can restrain the formation and aggregation of voids and subsequently improve the resistances to oxidation and spalling. The mechanism of the RE effect on the void band in the diffusion layer is also discussed. 展开更多
关键词 rare earth void band CRACK internal oxidation oxidation resistance spalling resistance aluminized steel
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几种锰氧化物矿物能带结构研究 被引量:6
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作者 刘菲菲 李艳 +2 位作者 丁竑瑞 丁聪 鲁安怀 《矿物岩石地球化学通报》 CSCD 北大核心 2017年第3期476-482,共7页
锰氧化物是常见的半导体材料之一,本文利用XRD、Raman、X射线吸收-发射谱及Zeta电位测试技术对合成的4种锰氧化物矿物(酸性水钠锰矿、碱性水钠锰矿、δ-MnO_2、锰钾矿)的能带结构进行了理论计算。结果表明,4种矿物均是可见光响应的半导... 锰氧化物是常见的半导体材料之一,本文利用XRD、Raman、X射线吸收-发射谱及Zeta电位测试技术对合成的4种锰氧化物矿物(酸性水钠锰矿、碱性水钠锰矿、δ-MnO_2、锰钾矿)的能带结构进行了理论计算。结果表明,4种矿物均是可见光响应的半导体矿物,其禁带宽度分别为2.32 eV、1.77 eV、1.36 eV、1.23 eV;在p H等于6时,4种锰氧化物矿物对应的导带电势分别为-0.32 V、0.09 V、0.39 V、0.46 V(vs.NHE),价带电势分别为2.00 V、1.86 V、1.75 V、1.69 V(vs.NHE)。与腐殖质氧化还原电势相比较,4种锰氧化物矿物在任何pH条件下均能吸收可见光催化氧化腐殖质。从结构上比较,层状结构比隧道结构的锰氧化物可见光催化氧化还原能力更强。 展开更多
关键词 半导体矿物 锰氧化物 光催化 能带结构
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ZnO/C复合光催化剂处理含Cr(VI)废水的试验研究
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作者 尤勇 常博 张利杰 《当代化工研究》 CAS 2023年第10期56-58,共3页
采用葡萄糖(glucose)还原水热法制备了ZnO/C复合光催化剂,并对其光催化还原含Cr(VI)废水的过程进行了研究。ZnO复合样品具有更窄的禁带宽度和更多的氧空位,从而进一步增加了可见光的利用效率和光吸收反应活性。ZnO/C光催化还原含铬废水... 采用葡萄糖(glucose)还原水热法制备了ZnO/C复合光催化剂,并对其光催化还原含Cr(VI)废水的过程进行了研究。ZnO复合样品具有更窄的禁带宽度和更多的氧空位,从而进一步增加了可见光的利用效率和光吸收反应活性。ZnO/C光催化还原含铬废水的最佳条件为:ZnO/glucose摩尔比15/1,废水pH值4.0和催化剂用量0.2g/L。在上述工艺下,300W氙灯光照反应3h后,废水中的Cr(VI)还原率在80%以上。在此基础上,同样对还原过程中废水的电化学反应特性进行了研究。 展开更多
关键词 光催化降解 Cr(VI)废水 氧空位 氧化锌 可见光 禁带宽度
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Multi-scale regulation in S,N co-incorporated carbon encapsulated Fe-doped CO_(9)S_(8) achieving efficient water oxidation with low overpotential 被引量:3
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作者 Wenbin Wang Yang Yang +4 位作者 Yang Zhao Shuzhe Wang Xiaomeng Ai Jiakun Fang Youwen Liu 《Nano Research》 SCIE EI CSCD 2022年第2期872-880,共9页
Sulfide compounds provide a type of promising alternative for oxygen evolution reaction(OER)electrocatalysts due to their diversity,intrinsic activities,low-price and earth-abundance.However,the unsmooth mass transpor... Sulfide compounds provide a type of promising alternative for oxygen evolution reaction(OER)electrocatalysts due to their diversity,intrinsic activities,low-price and earth-abundance.However,the unsmooth mass transport channel,the collapse of the structure and insufficient intrinsic activities limit their potential for OER performance.In respond,the dense Fe-doped Co_(9)S_(8) nanoparticles encapsulated by S,N co-incorporated carbon nanosheets(Fe-Co_(9)S_(8)@SNC)were proposed and synthesized via fast thermal treatment from ultrathin metal-organic frameworks(MOFs)nanosheets.In designed catalysts,the nanosheet configuration connected by nanoparticles retained rich access for permeation of electrolyte and precipitation of O_(2) bubbles during OER process.Meanwhile,the outer carbon layer of Co9S8 provided additional catalytic activity while acting as armor to keep the structure stability.At the atomic scale,the doped Fe regulated the local charge density and the d-band center for facilitating desorption of oxygen intermediates.Benefiting from this multi-scale regulation strategy,the Fe-Co_(9)S_(8)@SNC displays an ultralow overpotential of 273 mV at 10 mA·cm^(-2) and small Tafel slope of 55.8 mV·dec^(-1),which is even close to the benchmark RuO_(2) catalyst.This concept could provide valuable insights into the design of other catalysts for OER and beyond. 展开更多
关键词 Co9S8 water oxidation electronic structure multi-scale regulation d-band center
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金属-载体相互作用对负载Ag纳米颗粒催化氧化HMF性能的影响 被引量:3
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作者 夏海岸 安佳欢 +2 位作者 张维梓 葛超奇 左宋林 《林业工程学报》 CSCD 北大核心 2020年第6期88-93,共6页
5-羟甲基糠酸(HMFCA)是一种重要的生物质平台分子,目前主要使用贵金属催化剂来催化合成,存在产物选择性差、产率低等问题。因此,亟待开发一种相对廉价金属催化剂来高选择性合成HMFCA。笔者采用相对廉价的Ag金属作为活性组分,选用不同载... 5-羟甲基糠酸(HMFCA)是一种重要的生物质平台分子,目前主要使用贵金属催化剂来催化合成,存在产物选择性差、产率低等问题。因此,亟待开发一种相对廉价金属催化剂来高选择性合成HMFCA。笔者采用相对廉价的Ag金属作为活性组分,选用不同载体来考察金属-载体相互作用对5-羟甲基糖醛(HMF)氧化性能的影响。结果表明:载体的性质对Ag纳米粒子粒径以及HMF选择氧化性能具有显著的影响,其活性顺序为Ag/Zr O2>Ag/Al2O3>Ag/Ti O2>Ag/Ce O2>Ag/AC。此外,Ag/Zr O2催化剂Ag平均粒径(约9.6 nm)虽然和Ag/AC(约10.5 nm)相近,但Ag/Zr O2的活性远高于Ag/AC。由此可以说明,催化剂的HMF氧化活性与Ag纳米粒子表面的Ag0含量具有较好的线性关系,表明催化剂的活性中心主要为Ag纳米粒子表面的Ag0物种。Ag/Zr O2催化剂中Ag0含量最高,Ag/AC的Ag0含量最低,这可能是由于不同载体具有不同的金属-载体相互作用,从而影响催化剂上Ag纳米粒子表面的Ag0含量。 展开更多
关键词 5-羟甲基糠醛 5-羟甲基糠酸 选择氧化 d-带中心 载体
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Recent advances of two-dimensional CoFe layered-double-hydroxides for electrocatalytic water oxidation 被引量:2
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作者 Yi Zhou Jialai Hu +1 位作者 Lichun Yang Qingsheng Gao 《Chinese Chemical Letters》 SCIE CAS CSCD 2022年第6期2845-2855,共11页
Oxygen evolution reaction(OER)is pivotal to drive green hydrogen generation from water electrolysis,but yet is strictly overshadowed by the sluggish reaction kinetics.Earth-abundant and cut-price transitionmetal compo... Oxygen evolution reaction(OER)is pivotal to drive green hydrogen generation from water electrolysis,but yet is strictly overshadowed by the sluggish reaction kinetics.Earth-abundant and cut-price transitionmetal compounds,particularly Co Fe layered-double-hydroxides(LDHs),show the distinct superiorities in contrast to noble metals and their derivatives.In this review,we firstly underline their fundamental issues in electrocatalytic water oxidation,including Co Fe LDHs crystal structure,the surface of(hydr)oxides confined to OER and the controversial roles of Fe species,aiming at understanding the structure-related activity and catalytic mechanism.Advanced approaches for optimizing OER activity of Co Fe LDHs are then comprehensively overviewed,which will shed light on the different working mechanisms and provide a concise analysis of their unique advantages.Finally,a perspective on the future development of Co Fe LDHs electrocatalysts is offered.We hope this review can give a concise and explicit guidance for the development of transition-metal-based electrocatalysts in the energy field. 展开更多
关键词 CoFe layered-double-hydroxides Electrocatalytic water oxidation Two-dimensional nanostructures Surface reconstruction d-band
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Grey hematite photoanodes decrease the onset potential in photoelectrochemical water oxidation 被引量:1
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作者 Peng-Fei Liu Chongwu Wang +6 位作者 Yun Wang Yuhang Li Bo Zhang Li-Rong Zheng Zheng Jiang Huijun Zhao Hua-Gui Yang 《Science Bulletin》 SCIE EI CSCD 2021年第10期1013-1021,M0004,共10页
Photoelectrochemical(PEC)water splitting for solar energy conversion into chemical fuels has attracted intense research attention.The semiconductor hematite(α-Fe_(2)O_(3)),with its earth abundance,chemical stability,... Photoelectrochemical(PEC)water splitting for solar energy conversion into chemical fuels has attracted intense research attention.The semiconductor hematite(α-Fe_(2)O_(3)),with its earth abundance,chemical stability,and efficient light harvesting,stands out as a promising photoanode material.Unfortunately,its electron affinity is too deep for overall water splitting,requiring additional bias.Interface engineering has been used to reduce the onset potential of hematite photoelectrode.Here we focus instead on energy band engineering hematite by shrinking the crystal lattice,and the water-splitting onset potential can be decreased from 1.14 to 0.61 V vs.the reversible hydrogen electrode.It is the lowest record reported for a pristine hematite photoanode without surface modification.X-ray absorption spectroscopy and magnetic properties suggest the redistribution of 3d electrons in the as-synthesized grey hematite electrode.Density function theory studies herein show that the smaller-lattice-constant hematite benefits from raised energy bands,which accounts for the reduced onset potential. 展开更多
关键词 HEMATITE Photoelectrochemical water oxidation Onset potential Spin states Energy band
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4H-SiC MESFET工艺中的高温氧化及介质淀积技术 被引量:1
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作者 付兴昌 潘宏菽 《半导体技术》 CAS CSCD 北大核心 2012年第4期280-283,共4页
采用自主开发的4H-SiC高温氧化技术,并结合低压化学气相淀积方法,在器件表面形成较为致密的氧化层,降低了器件的反向泄漏电流,提高了器件的击穿电压,同时也提高了器件的输出功率及功率增益,为器件长期稳定可靠工作奠定了工艺基础。采用... 采用自主开发的4H-SiC高温氧化技术,并结合低压化学气相淀积方法,在器件表面形成较为致密的氧化层,降低了器件的反向泄漏电流,提高了器件的击穿电压,同时也提高了器件的输出功率及功率增益,为器件长期稳定可靠工作奠定了工艺基础。采用此技术后,单胞20 mm左右栅宽器件在2 GHz脉冲条件下(脉冲宽度300μs,占空比10%)输出功率达78 W,比原工艺的器件输出功率提高了20 W以上,功率增益提高了1.5 dB,达到8.9 dB左右,功率附加效率也从23%提升到32%,初步显示了该工艺技术在制备4H-SiC微波功率器件中的优势。 展开更多
关键词 碳化硅 微波功率器件 氧化 低压化学气相淀积 S波段
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一氧化碳在钯薄膜修饰的金电极上的电氧化-厚度的影响(英文)
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作者 Yuqing Yang Shouzhong Zou 《电化学》 CAS CSCD 北大核心 2010年第3期279-284,共6页
采用扫描循环伏安法及表面增强拉曼散射光谱研究了一氧化碳(CO)在钯修饰金电极上的吸附与氧化.结果表明CO氧化电位随钯膜厚度增加而正移,同时C—O伸缩振动频率红移.本文利用d能带理论解释观察现象.应力效应使CO吸附变强,难以氧化;但配... 采用扫描循环伏安法及表面增强拉曼散射光谱研究了一氧化碳(CO)在钯修饰金电极上的吸附与氧化.结果表明CO氧化电位随钯膜厚度增加而正移,同时C—O伸缩振动频率红移.本文利用d能带理论解释观察现象.应力效应使CO吸附变强,难以氧化;但配体效应使CO吸附变弱,易于氧化.在薄膜中配体效应强于应力效应. 展开更多
关键词 CO电氧化 Pd薄膜 d能带理论 表面增强拉曼散射
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Boosting fuel cell catalysis by surface doping of W on Pd nanocubes
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作者 Fawad Ahmad Laihao Luo +2 位作者 Xu Li Hongwen Huang Jie Zeng 《Chinese Journal of Catalysis》 SCIE EI CAS CSCD 北大核心 2018年第7期1202-1209,共8页
The development of active and durable non-Pt electrocatalysts with well-defined microstructure is of great importance to both fuel cell applications and fundamental understanding.Herein,we report a surface-doping proc... The development of active and durable non-Pt electrocatalysts with well-defined microstructure is of great importance to both fuel cell applications and fundamental understanding.Herein,we report a surface-doping process to prepare well-defined W-doped Pd nanocubes with a tunable atomic percent of W from 0 to 1.5%by using the Pd nanocubes as seeds.The obtained 1.2%W-doped Pd nanocubes/C exhibited greatly enhanced electrocatalytic performance toward oxygen reduction reaction in alkaline media,presenting an enhancement factor of 4.7 in specific activity and 2.5 in mass activity compared to the activity of a commercial Pt/C catalyst.The downshift of the d-band center due to a negative charge transfer from W to Pd intrinsically accounts for such improvement in activity by weakening the adsorption of reaction intermediates.Also,the 1.2%W-doped Pd nanocubes/C showed superior catalytic properties for the ethanol oxidation reaction,showing great potential for serving as a bifunctional electrocatalyst in fuel cells. 展开更多
关键词 Pd-based electrocatalyst Surface-doping process Oxygen reduction reaction Ethanol oxidation reaction d-band center
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X80管线钢高温氧化膜的生长机理 被引量:9
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作者 王畅 于洋 +2 位作者 牛涛 王林 陈瑾 《钢铁研究学报》 CAS CSCD 北大核心 2016年第5期57-63,共7页
观察并研究了X80钢在800-1 200℃下氧化1min的氧化膜以及氧化圆点的形成规律。结果表明:X80管线钢在1 050℃以下具有良好的抗氧化特性,从1 050℃开始整个氧化膜层明显增厚,抗氧化能力下降;在1 000℃以下氧化膜内侧区域存在明显的Si、C... 观察并研究了X80钢在800-1 200℃下氧化1min的氧化膜以及氧化圆点的形成规律。结果表明:X80管线钢在1 050℃以下具有良好的抗氧化特性,从1 050℃开始整个氧化膜层明显增厚,抗氧化能力下降;在1 000℃以下氧化膜内侧区域存在明显的Si、Cr富集带,温度升高到1 050℃,基体界面开始出现氧化圆点,同时内侧元素富集氧化膜的完整性遭到破坏,此种现象主要与Cr2O3进一步氧化形成CrO3有关。通过热力学和动力学分析发现,低于1 000℃,Si、Cr的氧化物稳定性高,自扩散系数小,利于形成界面处稳定的氧化膜。同时发现,1 050℃属于X80钢氧化质点形成的临界温度,低于此温度主要形成致密的界面氧化膜,它起到明显的抗氧化作用。 展开更多
关键词 氧化膜 热重试验 X80管线钢 元素富集
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氮化碳纳米片光电催化性能及界面反应机制 被引量:1
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作者 廖先龙 马晓清 《功能材料》 CAS CSCD 北大核心 2023年第8期8025-8034,共10页
石墨相氮化碳(g-C_(3)N_(4))由于低成本、易制备、高化学和热稳定性、合适的带隙等优点受到广泛关注。然而,传统热聚合法制备的g-C_(3)N_(4)片层结构不明显,具有比表面积小、易团聚和光催化活性低等缺点。以热氧化法制备得到氮化碳纳米... 石墨相氮化碳(g-C_(3)N_(4))由于低成本、易制备、高化学和热稳定性、合适的带隙等优点受到广泛关注。然而,传统热聚合法制备的g-C_(3)N_(4)片层结构不明显,具有比表面积小、易团聚和光催化活性低等缺点。以热氧化法制备得到氮化碳纳米片为模型,进行光电催化性能测试。探究了外加偏压对光电流方向的影响,并对光电诱导下的电极界面反应机制进行了讨论。分别通过X射线衍射(XRD)、电子显微镜(SEM/HRTEM)、X射线光电子能谱(XPS)、光致发光光谱(PL)和紫外-可见漫反射吸收光谱(UV-Vis DRS)表征了样品的结构、形貌、和光学特性。系统研究了在空气气氛下热氧化法对氮化碳结构和光电化学性能的影响。BET比表面积分析得到,经过热氧化法剥离的氮化碳纳米片的比表面积(160.6 m^(2)/g)较块状g-C_(3)N_(4)(12.5 m^(2)/g)提升了1个数量级。此外,二维纳米片结构的g-C_(3)N_(4)在紫外可见光照射下的光电流密度相较于块状g-C_(3)N_(4)提高了一倍,析氧过电位明显降低。 展开更多
关键词 氮化碳 纳米片 热氧化法 能带弯曲 光电响应
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Influence of MnO_(x)deposition on TiO_(2)nanotube arrays for electrooxidation
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作者 Kaihang Zhang Yuanzheng Zhang +6 位作者 Su Liu Xin Tong Junfeng Niu Dong Wang Junchen Yan Zhaoyang Xiong John Crittenden 《Green Energy & Environment》 SCIE EI CSCD 2023年第2期612-618,共7页
TiO_(2)has demonstrated outstanding performance in electrochemical advanced oxidation processes(EAOPs)due to its structural stability and high oxygen overpotential.However,there is still much room for improving its el... TiO_(2)has demonstrated outstanding performance in electrochemical advanced oxidation processes(EAOPs)due to its structural stability and high oxygen overpotential.However,there is still much room for improving its electrochemical activity.Herein,narrow bandgap manganese oxide(MnO_(x))was composited with TiO_(2)nanotube arrays(TiO_(2)NTAs)that in-situ oxidized on porous Ti sponge,forming the MnO_(x)-TiO_(2)NTAs anode.XANES and XPS analysis further proved that the composition of MnO_(x)is Mn2O3.Electrochemical characterizations revealed that increasing the composited concentration of MnO_(x)can improve the conductivity and reduce oxygen evolution potential so as to improve the electrochemical activity of the composited MnO_(x)-TiO_(2)NTAs anode.Meanwhile,the optimal degradation rate of benzoic acid(BA)was achieved using MnO_(x)-TiO_(2)NTAs with a MnO_(x)concentration of 0.1 mmol L^(-1),and the role of MnO_(x)was proposed based on DFT calculation.Additionally,the required electrical energy(EE/O)to destroy BA was optimized by varying the composited concentration of MnO_(x)and the degradation voltage.These quantitative results are of great significance for the design and application of high-performance materials for EAOPs. 展开更多
关键词 TiO_(2)nanotube arrays oxidation mechanism Energy efficiency assessment MnO_(x)band structure Electrochemical advanced oxidation processes
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