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苯酚降解用富氧空位BiVO4/NH2-MIL-125(Ti)光催化材料开发与应用 认领 引用
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作者 李成帅 李建章 +1 位作者 陈吉祥 张强 《工业催化》 CAS 2026年第6期62-69,共8页
采用水热法结合化学还原法制备了一种富氧空位BiVO4/NH2-MIL-125(Ti)复合光催化剂。利用XRD、UV-Vis DRS、SEM和ESR表征手段分析了催化剂的晶型结构、光吸收能力、微观形貌及表面氧空位含量等性质,并测试了催化剂的苯酚降解活性... 采用水热法结合化学还原法制备了一种富氧空位BiVO4/NH2-MIL-125(Ti)复合光催化剂。利用XRD、UV-Vis DRS、SEM和ESR表征手段分析了催化剂的晶型结构、光吸收能力、微观形貌及表面氧空位含量等性质,并测试了催化剂的苯酚降解活性。结果表明,BiVO4与NH2-MIL-125(Ti)的复合显著提高了材料的光吸收能力和光生载流子的分离效率,增强了光催化活性。在紫外光和苯酚初始浓度为50 mg/L条件下,NH2-MIL-125(Ti)添加量为30%(质量分数)的0.30-OBQMIL催化剂性能最优,90 min后苯酚降解率达到92.6%。此外,0.30-OBQMIL催化剂经过5次循环使用后,苯酚降解率仍在90%以上,具有良好的稳定性。自由基捕获实验确定了起主导作用的为超氧自由基(·O2-),其次为羟基自由基(·OH)和光生空穴(h+)。 展开更多
关键词 催化化学 BiVO4 NH2-MIL-125(Ti) 光催化 苯酚降解 氧空位
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Ti_2(OMe)_4SiO_2催化剂的制备及其合成碳酸二甲酯的反应性能 认领 引用 被引量：11
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作者 钟顺和 孔令丽 +1 位作者 黎汉生 肖秀芬 《燃料化学学报》 北大核心 2002年第5期454-458,共5页
采用表面改性和离子交换法制备了SiO2 负载的Ti2 (OMe) 4双核桥联配合物催化剂 ,用IR、TPD和微反技术考察了催化剂的表面构造及CO2 和CH3OH在催化剂表面上的化学吸附和反应性能。结果表明 :双核桥联配合物Ti2 (OMe) 4以Ti—O—Si键锚定... 采用表面改性和离子交换法制备了SiO2 负载的Ti2 (OMe) 4双核桥联配合物催化剂 ,用IR、TPD和微反技术考察了催化剂的表面构造及CO2 和CH3OH在催化剂表面上的化学吸附和反应性能。结果表明 :双核桥联配合物Ti2 (OMe) 4以Ti—O—Si键锚定在SiO2 表面上 ;CO2 在催化剂表面存在桥式和甲氧碳酸酯基两种吸附态 ,其中甲氧碳酸酯基吸附态是生成DMC的关键物种 ;CH3OH在催化剂上只有一种分子吸附态。在 15 0℃以下 ,CO2 和CH3OH在Ti2 (OMe) 4 SiO2 催化剂表面上高选择地生成碳酸二甲酯。 展开更多
关键词 Ti2(OMe)4/SiO2 催化剂 制备 合成 反应性能 二氧化碳 甲醇 碳酸二甲酯 SiO2载体 负载型双核钛桥联配合物 二氧化硅
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激光粉末床熔融制备Y2O3增强Ti6Al4V合金的组织与力学性能研究 认领 引用
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作者 董阳平 赵枢明 +14 位作者 朱金玉 张会华 赵文天 马国楠 庄辛鹏 孙预麟 杨鹏伟 张群 樊子煜 钟亮 杨广 鲁仁义 曹磊 马志远 王峰 《精密成形工程》 北大核心 2026年第2期21-30,共10页
目的针对Ti6Al4V合金在激光粉末床熔融(PBF-LB)过程中力学性能不足的问题,引入稀土氧化物Y2O3改善其性能。方法采用机械球磨法制备不同Y2O3含量的Ti6Al4V复合粉末,并通过PBF-LB技术成形合金件。利用扫描电镜、X射线衍射、... 目的针对Ti6Al4V合金在激光粉末床熔融(PBF-LB)过程中力学性能不足的问题,引入稀土氧化物Y2O3改善其性能。方法采用机械球磨法制备不同Y2O3含量的Ti6Al4V复合粉末,并通过PBF-LB技术成形合金件。利用扫描电镜、X射线衍射、电子背散射衍射和透射电镜等手段,系统分析了复合粉末及成形合金的微观结构、物相与元素分布;通过室温拉伸试验评估力学性能,并结合断口分析结果探究断裂机制。结果Y2O3在球磨后均匀附着于Ti6Al4V粉末表面。在PBF-LB成形过程中,Y2O3的引入显著细化了原始β晶粒和α/α'马氏体尺寸,并以纳米尺度的形式弥散分布在基体中,与α-Ti基体呈半共格关系。当Y2O3的质量分数为0.2%时,合金抗拉强度和屈服强度分别提高至1331 MPa和1208 MPa;但当Y2O3的质量分数增至0.3%时塑性下降。断口形貌由韧性韧窝逐渐转变为以解理面为主的脆性断裂。结论添加0.2%(质量分数)Y2O3能够细化原始β晶粒与α/α'马氏体组织,并通过纳米级Y2O3颗粒实现弥散强化。然而,当Y2O3质量分数增加至0.3%时,稀土氧化物颗粒发生团聚,引起局部应力集中,导致材料塑性严重下降。该研究为稀土氧化物在增材制造钛合金中的定量化改性提供了理论与实验依据。 展开更多
关键词 Ti6Al4V合金 Y2O3 激光粉末床熔融 增材制造 微观组织 力学性能
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基于ScCO2低温微量润滑工艺的CFRP/Ti6Al4V叠层结构钻削试验研究 认领 引用
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作者 李迎港 陈燕 +2 位作者 杨浩骏 郭南 陈德雄 《航空制造技术》 EI CSCD 北大核心 2026年第1期162-172,共11页
为了降低CFRP/Ti6Al4V叠层结构的钻削温度,提高钻削质量,利用超临界二氧化碳(Supercritical carbon dioxide,ScCO2)对润滑油具有高溶解性的特点,提出了低温微量润滑(Cryogenic minimum quantity lubrication,CMQL)工艺,进行了CMQL系... 为了降低CFRP/Ti6Al4V叠层结构的钻削温度,提高钻削质量,利用超临界二氧化碳(Supercritical carbon dioxide,ScCO2)对润滑油具有高溶解性的特点,提出了低温微量润滑(Cryogenic minimum quantity lubrication,CMQL)工艺,进行了CMQL系统油滴雾化效果测试和输出温度测试,开展了CMQL条件下CFRP/Ti6Al4V叠层结构的低频振动钻削试验,分析了CO2压力对切削加工性的影响。结果表明,增加CO2压力可以提高CMQL装置的雾化效果和冷却能力,压力增加至8 MPa,CO2为超临界态,其输出温度可低至-80℃以下;系统压力从5 MPa增至9 MPa,CFRP与Ti6Al4V层的钻削温度分别降低了15.91%和50.78%,轴向力分别增大了65.22%和20.26%,扭矩分别减小了23.33%和16.77%;Ti6Al4V层的出口毛刺高度降低42.04%,CFRP出口分层因子减小5.41%;在压力为7 MPa、8 MPa和9 MPa时,CFRP/Ti6Al4V叠层结构可得到较低的孔壁粗糙度。 展开更多
关键词 CFRP/Ti6Al4V叠层结构 低温微量润滑(CMQL)工艺 超临界二氧化碳(ScCO2) 钻削温度 钻削质量
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Effect of SiO2 addition on NH4HSO4 decomposition and SO2 poisoning over V2O5-MoO3/TiO2-CeO2 catalyst 认领 引用 被引量：11
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作者 Chengqiang Zheng Teng Cheng +2 位作者 Linjun Yang Hao Wu Hongmei Fan 《Journal of Environmental Sciences》 SCIE EI CAS CSCD 2020年第5期279-291,共13页
The deposition of NH4 HSO4 and the poisoning effect of SO2 on SCR catalyst are the main obstacles that restrict the industrial application of CeO2-doped SCR catalysts.In this work,deposited NH4 HSO4 decomposition beha... The deposition of NH4 HSO4 and the poisoning effect of SO2 on SCR catalyst are the main obstacles that restrict the industrial application of CeO2-doped SCR catalysts.In this work,deposited NH4 HSO4 decomposition behavior and SO2 poisoning over V2 O5-MoO3/TiO2 catalysts modified with CeO2 and SiO2 were investigated.By the means of characterization analysis,it was found that the addition of SiO2 into VMo/Ti-Ce had an impact on the interaction existed between catalyst surface atoms and NH4 HSO4.Temperatureprogrammed methods and in situ diffused reflectance infrared Fourier transform spectroscopy(DRIFTS)experiments indicated that the doping of SiO2 promoted the decomposition of deposited NH4 HSO4 on VMo/Ti-Ce catalyst surface by reducing the thermal stability of NH4 HSO4 and enhancing the NH4 HSO4 reactivity with NO in low temperature.And this improvement may be the reason for the better catalytic activity than VMo/Ti-Ce in the case of NH4 HSO4 deposition.Accompanied with cerium sulfate species generated over catalyst surface,the conversion of SO2 to SO3 was inhibited in SiCe mixed catalyst.The addition of SiO2 could promote the decomposition of cerium sulfate,which may be a potential strategy to enhance the resistance of SO2 poisoning over CeO2-modifed catalysts. 展开更多
关键词 CeO2-doped SCR catalyst SiO2 addition NH4HSO4 decomposition SO2 poisoning Cerium sulfate
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Luminescent properties of Ca_2SiO_4:Eu3+ red phosphor for trichromatic white light emitting diodes 认领 引用 被引量：12
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作者 余泉茂 刘玉峰 +3 位作者 吴珊 吕兴栋 黄新阳 李小侠 《Journal of Rare Earths》 SCIE EI CAS 2008年第6期783-786,共4页
The luminescent properties of Eu^3＋doped Ca2SiO4 red phosphors synthesized by the flux fusion reaction method were investigated. It was found that the excitation spectrum included two regions： the weak excitation ba... The luminescent properties of Eu^3＋doped Ca2SiO4 red phosphors synthesized by the flux fusion reaction method were investigated. It was found that the excitation spectrum included two regions： the weak excitation band below 325 nm and strong narrow peaks above 325 nm. The main peak of the excitation band was located at 400 nm. The peaks located at 290 nm were assigned to the combination of the charge transfer transition of O-Eu, peaks above 325 nm （325, 385, 400, 470, 511, and 539 nm） were assigned to the f-f transitions of Eu^3＋. The emission spectrum was dominated by the red peak located at 612 nm due to the electric dipole transition of ^5D0-^7F2. In addition, the effects of the Eu^3＋ content and charge compensators of Li^＋, Na^＋, K^＋, and Cl^- ions on the emission intensity were investigated. The experiment results suggested that the strongest emission was obtained when the concentration of the Eu^3＋ ions was 0.3 mol^-1, and Li^＋ ions gave the best improvement to enhance the emission intensity. Ca2SiO4：Eu^3＋, Li^＋ was thus suitable for low-cost trichromatic white light emitting diodes （WLED） based on UV InGaN chip. 展开更多
关键词 Ca2SiO4：Eu^3＋ red phosphor, WLED luminescent property rare earths
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Experimental investigation into Fe3O4/SiO2 nanoparticle performance and comparison with other nanofluids in enhanced oil recovery 认领 引用 被引量：5
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作者 Yousef Kazemzadeh Behnam Dehdari +2 位作者 Zahra Etemadan Masoud Riazi Mohammad Sharifi 《Petroleum Science》 SCIE CAS CSCD 2019年第3期578-590,共13页
Nanofluids because of their surface characteristics improve the oil production from reservoirs by enabling different enhanced recovery mechanisms such as wettability alteration,interfacial tension(IFT)reduction,oil vi... Nanofluids because of their surface characteristics improve the oil production from reservoirs by enabling different enhanced recovery mechanisms such as wettability alteration,interfacial tension(IFT)reduction,oil viscosity reduction,formation and stabilization of colloidal systems and the decrease in the asphaltene precipitation.To the best of the authors’ knowledge,the synthesis of a new nanocomposite has been studied in this paper for the first time.It consists of nanoparticles of both SiO2 and Fe3O4.Each nanoparticle has its individual surface property and has its distinct effect on the oil production of reservoirs.According to the previous studies,Fe3O4 has been used in the prevention or reduction of asphaltene precipitation and SiO2 has been considered for wettability alteration and/or reducing IFTs in enhanced oil recovery.According to the experimental results,the novel synthesized nanoparticles have increased the oil recovery by the synergistic effects of the formed particles markedly by activating the various mechanisms relative to the use of each of the nanoparticles in the micromodel individually.According to the results obtained for the use of this nanocomposite,understanding reservoir conditions plays an important role in the ultimate goal of enhancing oil recovery and the formation of stable emulsions plays an important role in oil recovery using this method. 展开更多
关键词 Enhanced oil recovery Asphaltene precipitation Wettability alteration Interfacial tension reduction Fe3O4/SiO2 nanofluid
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The effects of radiation damage on power VDMOS devices with composite SiO_2-Si_3N_4 films 认领 引用 被引量：3
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作者 高博 刘刚 +5 位作者 王立新 韩郑生 宋李梅 张彦飞 腾瑞 吴海舟 《Chinese Physics B》 SCIE EI CAS CSCD 2013年第3期393-398,共6页
Total dose effects and single event effects on radiation-hardened power vertical double-diffusion metal oxide semiconductor（VDMOS） devices with composite SiO2-Si3N4 film gates are investigated.The relationships amon... Total dose effects and single event effects on radiation-hardened power vertical double-diffusion metal oxide semiconductor（VDMOS） devices with composite SiO2-Si3N4 film gates are investigated.The relationships among the important electrical parameters of the samples with different thickness SiO2-Si3N4 films,such as threshold voltage,breakdown voltage,and on-state resistance in accumulated dose,are discussed.The total dose experiment results show that the breakdown voltage and the on-state resistance barely change with the accumulated dose.However,the relationships between the threshold voltages of the samples and the accumulated dose are more complex,and not only positively drift,but also negatively drift.At the end of the total dose experiment,we select the group of samples which have the smaller threshold voltage shift to carry out the single event effect studies.We find that the samples with appropriate thickness ratio SiO2-Si3N4 films have a good radiation-hardening ability.This method may be useful in solving both the SEGR and the total dose problems with the composite SiO2-Si3N4 films. 展开更多
关键词 power VDMOS device total dose effects single event effects composite SiO2-Si3N4 films
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Highly Efficient and Recyclable Catalyst HBF_4·SiO2Catalyzed Synthesis ofβ-Enamino Compounds Under Solvent-free Conditions 认领 引用 被引量：2
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作者 GAO Han JIA Xu-dong +4 位作者 DUAN Hai-feng LIN Ying-jie GAO Jun-gang LIANG Da-peng WU Mao-cheng 《Chemical Research in Chinese Universities》 SCIE CAS CSCD 2011年第5期792-794,共3页
Fluoroboric acid adsorbed on silica-gel(HBF4·SiO2)has been found to be an extremely efficient and recyclable catalyst for the preparation ofβ-enaminones andβ-enamino esters under solvent-free conditions.
关键词 β-Enaminone β-Enamino ester HBF4·SiO2 Solvent-free condition
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Construction of SiO2-TiO2/g-C3N4 composite photocatalyst for hydrogen production and pollutant degradation: Insight into the effect of SiO2 认领 引用 被引量：1
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作者 Sijia Sun Hao Ding +5 位作者 Lefu Mei Ying Chen Qiang Hao Wanting Chen Zhuoqun Xu Daimei Chen 《Chinese Chemical Letters》 SCIE CAS CSCD 2020年第9期2287-2294,共8页
Using low-cost precipitated silica(SiO2) as the carrier,a ternary SiO2-TiO2/g-C3N4 composite photocatalyst was prepared via the sol-gel method associated with a wet-grinding process.The asprepared composite exhibits p... Using low-cost precipitated silica(SiO2) as the carrier,a ternary SiO2-TiO2/g-C3N4 composite photocatalyst was prepared via the sol-gel method associated with a wet-grinding process.The asprepared composite exhibits photocatalytic hydrogen production and pollutant degradation performance under solar-like irradiation.The effect of SiO2 carrier on the properties of the heterostructure between TiO2 and g-C3N4(CN) was systematically studied.It is found that SiO2 has important effects on promoting the interaction between TiO2 and CN.The particle size of TiO2 and CN was obviously reduced during the calcination process due to the effects of SiO2.Especially,the TiO2 particles exhibit monodispersed state with particle size below 10 nm(quantum dots),resulting in the improvement of the contact area and the interaction betweenTiO2 and CN,and leading to the formation of efficient TiO2/CN Zscheme heterostructure in SiO2-TiO2/CN.Besides,the introduction of SiO2 can increase the specific surface area and light absorption of SiO2-TiO2/CN,further promoting the photocatalytic reaction.As expected,the optimum SiO2-TiO2/CN composite exhibits 12.3,3.1 and 2.9 times higher photocatalytic hydrogen production rate than that of SiO2-TiO2,CN and TiO2/CN under solar-like irradiation,while the photocatalytic active component in SiO2-TiO2/CN is only about 60 wt%.Moreover,the rhodamine B degradation rate of SiO2-TiO2/CN is also higher than that of SiO2-TiO2,CN and TiO2/CN. 展开更多
关键词 SiO2 carrier Heterostructure Photocatalyst g-C3N4 TiO2
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Fabrication and characterization of SiO2(f)/Si)_3N_4 composites 认领 引用 被引量：4
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作者 Yongsheng Liu Laifei Cheng +2 位作者 Litong Zhang Yongdong Xu Yi Liu 《Journal of University of Science and Technology Beijing》 2007年第5期454-459,共6页
A silicon dioxide fiber-reinforced silicon nitride matrix(SiOJSi3N4)composite used for radomes was prepared by chemical vapor infiltration(CVI)process using the SiCl4-NH3-H2 system.The effects of the process condition... A silicon dioxide fiber-reinforced silicon nitride matrix(SiOJSi3N4)composite used for radomes was prepared by chemical vapor infiltration(CVI)process using the SiCl4-NH3-H2 system.The effects of the process conditions,including infiltration temperature,infiltration time,and gas flux were investigated.The energy dispersion spectra(EDS)result showed that the main elements of this composite contained Si,N,and O.The X-ray diffraction(XRD)results indicated that phases of the composite before and after treatment at 1350℃were all amorphous.A little fiber pull-out was observed on the cross section of the composite by scan electron microscope(SEM).As a result,the composite exhibited good thermal stability,but an appropriate interface was necessary between the fiber and the matrix. 展开更多
关键词 SiO2/Si3N4 composite fabrication characterization chemical vapor infiltration
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Reaction mechanism of molten Na OH decomposing Zn_2SiO_4 in willemite 认领 引用 被引量：2
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作者 赵昌明 翟玉春 +2 位作者 张崇民 李军丽 李胜利 《Journal of Central South University》 SCIE EI CAS CSCD 2015年第4期1227-1231,共5页
Based on the existing form of Zn2 Si O4 in willemite, the chemical precipitation method was used to synthesize Zn2 Si O4.Through the orthogonal experimentation, the reaction conditions of melten Na OH decomposing Zn2 ... Based on the existing form of Zn2 Si O4 in willemite, the chemical precipitation method was used to synthesize Zn2 Si O4.Through the orthogonal experimentation, the reaction conditions of melten Na OH decomposing Zn2 Si O4 were optimized, and the optimal experimental conditions include reaction temperature of 400 °C, reaction time of 4 h, and alkaline-to-ore molar ratio of 20:1.Based on the optimized experiment, on-line detection for the alkali leaching was made by using Raman spectroscopy; XRD was used to analyze the structure of water leaching residue, to explore the reaction mechanism of Na OH decomposing Zn2 Si O4. The results show that during the reaction process, the Si — O bond in Si O4 is destroyed, and the Na OH inserts itself into the silicate lattice,producing an immediate Na2 Zn Si O4 product. After the alkali leaching process, Zn2+ can be separated from the Si O4 array, which can be released out of the silicate in the form of ZnO. 展开更多
关键词 Raman spectroscopy Zn2SiO4 alkali melting reaction mechanism
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Photoluminescence Properties and Energy Transfer from Ce3+ to Tb3+ in Zn_2SiO-_4 Host 认领 引用 被引量：1
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作者 熊晓波 袁曦明 +3 位作者 LIANG Yujun SONG Jiangqi WU Qi YIN Guoxiang 《Journal of Wuhan University of Technology(Materials Science)》 SCIE EI CAS 2015年第2期235-240,共6页
Zn2Si O4︰Tb^3＋, Zn2 Si O4︰Ce^3＋, Zn2 Si O4︰Tb^3＋, Ce^3＋ phosphors were prepared by solidstate reaction at 1 150 ℃ for 2h under a weak reducing atmosphere. Moreover, the XRD patterns and photoluminescence spect... Zn2Si O4︰Tb^3＋, Zn2 Si O4︰Ce^3＋, Zn2 Si O4︰Tb^3＋, Ce^3＋ phosphors were prepared by solidstate reaction at 1 150 ℃ for 2h under a weak reducing atmosphere. Moreover, the XRD patterns and photoluminescence spectra were recorded and the effects of Tb3＋ and Ce3＋ concentration on the luminescent properties of as-synthesized phosphors were investigated. The emission spectra under ultraviolet light（333 nm） radiation showed a dominant peak at 542 nm attributed to the 5D4→7F5 transition of Tb^3＋, which was enhanced significantly（about 45 times） by the co-doping of Ce^3＋, indicating that there occurred an efficient energy transfer from Ce^3＋ to Tb^3＋. According to the Dexter＇s energy transfer formula of multipolar interaction, it was demonstrated that the energy transfer between Ce3＋ and Tb3＋ was due to the electric dipolar-dipolar interaction of the resonance transfer. 展开更多
关键词 phosphors emission Zn2SiO4：Tb^3＋ Ce^3＋ transition energy transfer
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Ti表面Ag/g-C3N4共敏化TiO2纳米膜的构筑及其光电化学行为 认领 引用 被引量：1
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作者 官自超 胡娟 +5 位作者 时海燕 董士刚 刘亚安 王霞 金飘 杜荣归 《金属学报》 SCIE EI CAS CSCD 北大核心 2025年第12期1769-1780,共12页
为提高Ti基体表面TiO2半导体膜的光电化学性能,对不锈钢实施光电化学阴极保护,本工作预先用阳极氧化法在Ti表面构筑TiO2纳米管阵列膜,再依次通过化学气相沉积和化学浴沉积法在阵列膜表面负载类石墨相氮化碳(g-C3N4)和Ag,获... 为提高Ti基体表面TiO2半导体膜的光电化学性能,对不锈钢实施光电化学阴极保护,本工作预先用阳极氧化法在Ti表面构筑TiO2纳米管阵列膜,再依次通过化学气相沉积和化学浴沉积法在阵列膜表面负载类石墨相氮化碳(g-C3N4)和Ag,获得了高性能的Ag/g-C3N4共敏化TiO2纳米管复合膜光阳极。相比于TiO2纳米管膜,经Ag/g-C3N4共敏化后,Ag/g-C3N4/TiO2复合膜的光吸收范围扩展到可见光区,光学性能显著增强。白光照射下,复合膜在含0.2 mol/L NaOH的含50%(体积分数)乙二醇水溶液中的光电流密度达到纯TiO2纳米膜的11倍,表现出优良的光电化学性能。Ti表面Ag/g-C3N4/TiO2纳米管复合膜作为光阳极,可使403不锈钢在0.5 mol/L NaCl溶液中的电极电位相对于自腐蚀电位降低530 mV,光电化学阴极保护效应显著增强,对控制不锈钢腐蚀发挥了良好作用。 展开更多
关键词 Ti 阳极氧化 化学气相沉积 化学浴沉积 TiO2纳米管 g-C3N4 Ag 光电化学阴极保护
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Surface modification of LiCo0.05Mn1.95O_4 cathode by coating with SiO_2-TiO_2 composite 认领 引用 被引量：1
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作者 禹筱元 胡国荣 +3 位作者 彭忠东 肖劲 陈召勇 刘业翔 《中国有色金属学会会刊：英文版》 2004年第4期723-727,共5页
The cycling characteristics and low specific capacity of LiMn2O4 have always been the greatest obstacle to its commercialization. For the improvement of cyc le performance,the surface of LiCo0.05Mn1.95O4 was coated wi... The cycling characteristics and low specific capacity of LiMn2O4 have always been the greatest obstacle to its commercialization. For the improvement of cyc le performance,the surface of LiCo0.05Mn1.95O4 was coated with ve ry fine SiO2-TiO2 composite prepared by sol-gel method. The structure and morphology of the coating materials were investigated by X-ray diffraction （XRD ） and scanning electron microscope （SEM）. The electrochemical performances of un coated and SiO2-TiO2 coated LiCo0.05Mn1.95O4 spinel at 25 ℃ and 55 ℃ were studied with a voltage range of 3.04.35V and a current density of 0.1 mA/cm2. There is a slight decrease in the initial discharge ca pacity of coated LiCo0.05Mn1.95O4（119 mA·h/g） compared with that of uncoated （123 mA·h/g）. However the cycle ability of LiCo0.05Mn1. 95O4 coated by SiO2-TiO2 is improved. It is proposed that surface treat ment is an effective method to improve the cycle performance of LiCo0.05Mn 1.95O4. The surface modification is successful in minimizing the harmful side reactions within the batteries by placing a protective barrier layer betwe en the oxidizing cathode material and the liquid electrolyte. 展开更多
关键词 SiO2-TiO2 复合涂层 表面改性 LiCo0.05Mn1.95O4 锂离子电池 电极材料
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Ti/TiHx-NiCO2O4阳极电化学氧化氨苄西林的研究 认领 引用
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作者 张媛媛 周川乂 +1 位作者 饶永芳 延卫 《西安交通大学学报》 EI CAS CSCD 北大核心 2025年第11期53-62,共10页
针对新型有机污染物氨苄西林长期累积引发的耐药性风险及环境危害问题,基于低成本、高导电性与催化活性的NiCO2O4材料,开发环境友好型电化学氧化新型钛阳极材料。首先,采用电沉积法制备Ti/TiHx-NiCO2O4电极,通过催化活... 针对新型有机污染物氨苄西林长期累积引发的耐药性风险及环境危害问题,基于低成本、高导电性与催化活性的NiCO2O4材料,开发环境友好型电化学氧化新型钛阳极材料。首先,采用电沉积法制备Ti/TiHx-NiCO2O4电极,通过催化活性和线性扫描伏安法、电化学阻抗谱等系统电化学表征工艺参数优化;其次,探究了反应过程中初始pH、电流密度等因素对氨苄西林降解效果的影响;最后,进行了自由基捕获实验和加速寿命测试。结果表明:Ti/TiHx-NiCO2O4电极的最佳制备条件为电流密度20 mA·cm-2、硝酸镍浓度为0.5 mol·L-1、镀膜层数为3层;碱性(pH=9.97)条件下,氨苄西林降解速率最快,20 min内可去除97%的质量浓度为50 mg·L-1的氨苄西林;降解时所用的最佳电流密度为10 mA·cm-2,此条件下质量浓度50 mg·L-1的氨苄西林可在40 min内被完全去除;Ti/TiHx-NiCO2O4电极氧化的反应机理是直接氧化(直接电子转移)与间接氧化(羟基自由基作用)作用并存;Ti/TiHx-NiCO2O4阳极的稳定使用寿命超过90 h,表面钝化和活性成分浸出是其主要的失活途径。 展开更多
关键词 电化学氧化 氨苄西林 Ti/TiHx-NiCO2O4电极 工艺参数优化 反应机理
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Ce-promoted Mn/Na_2 WO_4/SiO_2 catalyst for oxidative coupling of methane at atmospheric pressure 认领 引用 被引量：4
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作者 Seyed Mehdi Kamali Shahri Ali Nakhaei Pour 《Journal of Natural Gas Chemistry》 2010年第1期47-53,共7页
A series of Ce-promoted Mn-Na2WO4/SiO2 catalysts were prepared by incipient wetness impregnation method, and their catalytic performance for oxidative coupling of methane （OCM） was investigated at atmospheric pressu... A series of Ce-promoted Mn-Na2WO4/SiO2 catalysts were prepared by incipient wetness impregnation method, and their catalytic performance for oxidative coupling of methane （OCM） was investigated at atmospheric pressure in a micro-quartz-tube reactor. The catalysts were characterized by X-ray diffraction （XRD）, temperature program reduction （TPR） and BET surface area. Ce promoter increased surface area and Na2WO4 species dispersion, which enriched the amount of the surface species. In addition, Ce promoter increased the Na/W species reduction, but the reduction peak shifted to higher temperature. Stability test of 5wt%Ce catalyst indicated suitable performance and stability. The selectivity and yield of C^2＋ hydrocarbons after 50 h operation reached 65.5% and 19.6%, respectively, at 840 ℃ over 5wt%Ce-2wt%Mn5wt%Na2WO4/SiO2 catalyst. 展开更多
关键词 oxidative coupling of methane CeO2 promoter Mn/Na2WO4/SiO2
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Ti4+掺杂对正极材料LiNi0.75Mn0.25O2结构与电化学性能的影响 认领 引用 被引量：2
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作者 孟德轩 李振京 +2 位作者 范广新 蔡海洋 刘超帅 《现代化工》 CAS CSCD 北大核心 2025年第1期105-111,共7页
以TiO2为添加剂,利用高温固相法对锂离子电池正极材料LiNi0.75Mn0.25O2进行掺杂,通过XRD、SEM、XPS和电化学测试等对材料进行表征。结果表明,Ti4+可成功掺入LiNi0.75Mn0.25O2中,在掺杂的Li[Ni0.75Mn0.25]... 以TiO2为添加剂,利用高温固相法对锂离子电池正极材料LiNi0.75Mn0.25O2进行掺杂,通过XRD、SEM、XPS和电化学测试等对材料进行表征。结果表明,Ti4+可成功掺入LiNi0.75Mn0.25O2中,在掺杂的Li[Ni0.75Mn0.25]1-xTixO2(0≤x≤0.02)中,Ti4+不改变材料的物相和形貌,但对电化学性能有较大影响。在最佳掺Ti4+摩尔分数为1.5%时,经50周循环后材料的容量保持率由87.87%提高到95.42%,4 C放电比容量由66.47 mAh/g提升为104.00 mAh/g。 展开更多
关键词 锂离子电池 正极 LiNi0.75Mn0.25O2 Ti4+掺杂
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Enhanced hyperthermia performance in hard-soft magnetic mixed Zn0.5CoxFe2.5−xO4/SiO2 composite magnetic nanoparticles 认领 引用
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作者 Xiang Yu Li-Chen Wang +3 位作者 Zheng-Rui Li Yan Mi Di-An Wu Shu-Li He 《Chinese Physics B》 SCIE EI CAS CSCD 2021年第3期409-415,共7页
High quality Zn0.5CoxFe2.5−xO4(x=0,0.05,0.1,0.15)serial magnetic nanoparticles with single cubic structures were prepared by the modified thermal decomposition method,and Zn0.5CoxFe2.5−xO4/SiO2 composite magnetic nano... High quality Zn0.5CoxFe2.5−xO4(x=0,0.05,0.1,0.15)serial magnetic nanoparticles with single cubic structures were prepared by the modified thermal decomposition method,and Zn0.5CoxFe2.5−xO4/SiO2 composite magnetic nanoparticles were prepared by surface modification of SiO2.The magnetic anisotropy of the sample increases with the increase of the doping amount of Co2+.When the doping amount is 0.1,the sample shows the transition from superparamagnetism to ferrimagnetism at room temperature.In the Zn0.5CoxFe2.5−xO4/SiO2 serial samples,the maximum value of specific loss power(SLP)with 1974 W/gmetal can also be found at doping amount of x=0.1.The composite nanoparticles are expected to be an excellent candidate for clinical magnetic hyperthermia. 展开更多
关键词 magnetic nanoparticles magnetic anisotropy Zn0.5CoxFe2.5−xO4/SiO2 magnetic hyperthermia
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Calculation of photon attenuation coefficient and dose rate in concrete with the addition of SiO_2 and MnFe_2O_4 nanoparticles using MCNPX code and comparison with experimental results 认领 引用
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作者 M.Hassanzadeh S.M.Sadat Kiai 《Nuclear Science and Techniques》 SCIE EI CAS CSCD 2018年第11期152-158,共7页
One of the most important safety features of nuclear facilities is the shielding material used to protect the operating personnel from radiation exposure. The most common materials used in radiation shielding are conc... One of the most important safety features of nuclear facilities is the shielding material used to protect the operating personnel from radiation exposure. The most common materials used in radiation shielding are concretes. In this study, a Monte Carlo N-Particle eXtended code is used to calculate the gamma-ray attenuation coefficients and dose rates for a new concrete material composed of MnFe_2O_4 nanoparticles, which is then compared with the theoretical and experimental results obtained for a SiO_2 nanoparticle concrete material. According to the results, the average relative differences between the simulations and the theoretical and experimental results for the linear attenuation coefficient(l) in the SiO_2 nanoparticle materials are 6.4% and 5.5%, respectively. By increasing the SiO_2 content up to 1.5% and the temperature of MnFe_2O_4 up to 673 K, l is increased for all energies. In addition, the photon dose rate decreases up to 9.2% and3.7% for MnFe_2O_4 and SiO_2 for gamma-ray energies of0.511 and 1.274 MeV, respectively. Therefore, it was concluded that the addition of SiO_2 and MnFe_2O_4 nanoparticles to concrete improves its nuclear properties and could lead to it being more useful in radiation shielding. 展开更多
关键词 Shielding Radiation Concrete Attenuation coefficient Photon dose MCNPX code SiO2 and MnFe2O4 nanoparticles
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