CoS Nanosheets Coated with Dopamine-Derived Carbon Standing on Carbon Fiber Cloth as Binder-Free Anode for Li-ion Batteries

Cobalt sulphides attract much attention as anode materials for Li-ion batteries(LIBs).However,its poor conductivity,low initial column efficiency and large volume changes during cycling have hindered its further development.Herein,novel interlaced CoS nanosheets were firstly prepared on Carbon Fiber Cloth(CFC)by two hydrothermal reactions followed with carbon coating via carbonizing dopamine(CoS NS@C/CFC).As a freestanding anode,the nanosheet structure of CoS not only accommodates the volume variation,but also provides a large interface area to proceed the charge transfer reaction.In addition,CFC works as both a three-dimensional skeleton and an active substance which can further improve the areal capacity of the resulting electrode.Furthermore,the coated carbon combined with the CFC work as a 3D conductive network to facilitate the electron conduction.The obtained CoS NS@C/CFC,and the contrast sample prepared with the same procedure but without carbon coating(CoS NS/CFC),are characterized with XRD,SEM,TEM,XPS and electrochemical measurements.The results show that the CoS NS@C/CFC possesses much improved electrochemical performance due to the synergistic effect of nanosheet CoS,the coated carbon and the CFC substrate,exhibiting high initial columbic efficiency(~87%),high areal capacity(2.5 at 0.15 mA cm−2),excellent rate performance(1.6 at 2.73 mA cm−2)and improved cycle stability(87.5%capacity retention after 300 cycles).This work may provide a new route to explore freestanding anodes with high areal specific capacity for LIBs.

Adsorption onto Activated Carbon Fiber Cloth and Electrothermal Desorption of Volatile Organic Compound(VOCs):A Specific Review

A general research program, focusing on activated carbon fiber cloths （ACFC） and felt for environmental protection was performed. The objectives were multiple： （i） a better understanding of the adsorption mecha- nisms of these kinds of materials; （ii） the specification and optimization of new processes using these adsorbents; （iii） the modeling of the adsorption of organic pollutants using both the usual and original approaches; （iv） applications of ACFC in industrial processes. The general question was： how can activated carbon fiber cloths and felts be used in air treatment processes for the protection of environment. In order to provide an answer, different approaches were adopted. The materials （ACFC） were characterized in terms of macro structure and internal porosity. Specific studies were performed to get the air flow pattern through the fabrics. Head loss data were generated and modeled as a fi.mction of air velocity. The performances of ACF to remove volatile organic compounds （VOCs） were approached with the adsorption isotherms and breakthrough curves in various operating conditions. Regenera- tion by Joule effect shows a homogenous heating of adsorber modules with rolled or pleated layers. Examples of industrial developments were presented showing an interesting technology for the removal of VOCs, such as dichloromethane, benzene, isopropyl alcohol and toluene, alone or in a complex mixture.

Electrodeposited NiSe2 on carbon fiber cloth as a flexible electrode for high-performance supercapacitors

A flexible electrode of nickel diselenide/carbon fiber cloth(NiSe/CFC) is fabricated at room temperature by a simple and efficient electrodeposition method. Owing to NiSecharacter of nanostructure and high conductivity, the as-synthesized electrodes possess perfect pseudocapacitive property with high specific capacitance and excellent rate capability. In three-electrode system, the electrode specific capacitance of the NiSe/CFC electrode varies from 1058 F gto 996.3 F gat 2 A gto 10 A grespectively, which shows great rate capability. Moreover, the NiSeelectrode is assembled with an active carbon(AC) electrode to form an asymmetric supercapacitor with an extended potential window of 1.6 V. The asymmetric supercapacitor possesses an excellent energy density 32.7 Wh kgwith a power density 800 W kgat the current density of 1 A g. The nanosheet array on carbon fiber cloth with high flexibility, specific capacitance and rate capacitance render the NiSeto be regarded as the promising material for the high performance superconductor.

Boosting Capacitive Deionization Performance of Commercial Carbon Fibers Cloth via Structural Regulation Based on Catalytic-Etching Effect

Monolithic carbon electrodes with robust mechanical integrity and porous architecture are highly desired for capacitive deionization but remain challenging.Owing to the excellent mechanical strength and electroconductivity,commercial carbon fibers cloth demonstrates great potential as high-performance electrodes for ions storage.Despite this,its direct application on capacitive deionization is rarely reported in terms of limited pore structure and natural hydrophobicity.Herein,a powerful metal-organic framework-engaged structural regulation strategy is developed to boost the desalination properties of carbon fibers.The obtained porous carbon fibers features hierarchical porous structure and hydrophilic surface providing abundant ions-accessible sites,and continuous graphitized carbon core ensuring rapid electrons transport.The catalytic-etching mechanism involving oxidation of Co and subsequent carbonthermal reduction is proposed and highly relies on annealing temperature and holding time.When directly evaluated as a current collector-free capacitive deionization electrode,the porous carbon fibers demonstrates much superior desalination capability than pristine carbon fibers,and remarkable cyclic stability up to 20 h with negligible degeneration.Particularly,the PCF-1000 showcases the highest areal salt adsorption capacity of 0.037 mg cm^(−2) among carbon microfibers.Moreover,monolithic porous carbon fibers-carbon nanotubes with increased active sites and good structural integrity by in-situ growth of carbon nanotubes are further fabricated to enhance the desalination performance(0.051 mg cm^(−2)).This work demonstrates the great potential of carbon fibers in constructing high-efficient and robust monolithic electrode for capacitive deionization.

Vapor-phase hydrothermal growth of single crystalline NiS2 nanostructure film on carbon fiber cloth for electrocatalytic oxidation of alcohols to ketones and simultaneous H2 evolution

Electrocatalytic synthesis of value-added chemicals is attracting significant research attention owing to its mild reaction conditions, environmental benignity, and potentially scalable application to organic synthetic chemistry. Herein, we report the preparation of a single-crystalline NiS2 nanostructure film of N 50 nm thickness grown directly on a carbon fiber doth （NiSJCFC） by a facile vapor-phase hydrothermal （VPH） method. NiSJCFC as an electrocatalyst exhibits activity for both the oxygen evolution reaction （OER） and the hydrogen evolution reaction （HER） in alkaline media. Furthermore, a series of alcohols （2-propanol, 2-butanol, 2-pentanol, and cyclohexanol） were electrocatalytically converted to the corresponding ketones with high selectivity, efficienc and durability using the NiSJCFC electrode in alkaline media. In the presence of 0.45 M alcohol, a remarkably decreased overpotential （- 150 mV, vs. RHE） at the NiS2/CFC anode compared with that for water oxidation to generate O2, i.e., the OER, in alkaline media leads to significantly improved H2 generation. For instance, the H2 generation rate in the presence of 0.45 M 2-propanol is almost 1.2-times of that obtained for pure water splitting, but in a system that employs an applied voltage at least 280 mV lower than that required for water splitting to achieve the same current density （20 mA-crn-2）. Thus, our results demonstrate the applicability of our bifunctional non-precious-metal electrocatalyst for organic synthesis and simultaneous H2 production.

Optimizing the micropore-to-mesopore ratio of carbon-fiber-cloth creates record-high specific capacitance

The application of commercial carbon fiber cloth(CFC) in energy storage equipment is limited by its low specific capacitance and energy density. By a simple one-step activation treatment, the specific surface area of CFCs with porous structure can be increased considerably from 3.9 up to 875 m^2/g and the electrochemical properties of CFCs can be improved by three orders of magnitude(1324 mF/cm^2). Moreover,the hydrophobicity of CFCs can be transformed into superhydrophilicity. However, the electrochemical performance of CFCs does not show a positive correlation with specific surface area but have a strong relationship with the hierarchical pore distribution forged by the annealing treatment. Only moderate micropore and mesoporous ratio enables optimizing the electrochemical performance of CFCs.

Growth of BiOBr/ZIF‑67 Nanocomposites on Carbon Fiber Cloth as Filter‑Membrane‑Shaped Photocatalyst for Degrading Pollutants in Flowing Wastewater

BiOBr-based nanocomposite photocatalysts are used for removing the organic pollutants,but their poor adsorption/photocatalytic performances and the low potential for recycling limit their application.To solve the issue,herein we report a large-area recyclable CFC/BiOBr/ZIF-67 filter-membrane-shaped photocatalyst prepared by in situ growth of BiOBr/ZIF-67 nanocomposites on carbon fiber cloth(CFC).Fabrication process is based on hydrothermal synthesis of BiOBr nanosheets(diameter 0.5–1μm)on carbon fiber cloth(as substrate material)and then a chemical bath route is used to grow ZIF-67 nanoparticles(diameter 300–600 nm)in situ on the surface of CFC/BiOBr.Resulted composite,CFC/BiOBr/ZIF-67,exhibits a high specific surface area(545.82 m^(2) g^(−1))and a wide photoabsorption,accompanied by an absorption edge(~620 nm).In dark condition,CFC/BiOBr/ZIF-67 adsorbs bisphenol A(BPA)and orange 7(AO7)within 60 min,respectively with 20.0% and 40.1% efficiency.This level of efficiencies are correspondingly 2.6 and 3.2 times more that of the bare CFC/BiOBr(7.6%for BPA and 12.4% for AO7).Under visible light irradiation,CFC/BiOBr/ZIF-67 can degrade 69.7% of BPA and 96.0% of AO7,in 120 min,which are,respectively,1.3 and 1.8 times higher than the absorption efficiency of bare CFC/BiOBr(53.2% for BPA,52.0% for AO7).When CFC/BiOBr/ZIF-67 is used as a filter membrane for photocatalytic removal of pollutants in flowing wastewater(AO7,rate:~1.5 L h^(−1)),92.2%of AO7 can be decomposed after 10 filtering cycles.This study suggests CFC/BiOBr/ZIF-67 as a novel highly functional,recyclable and environmental friendly photo-driven membrane filter for purification and recovery of flowing surface waste waters.

Construction of n-TiO_(2)/p-Ag_(2)O Junction on Carbon Fiber Cloth with Vis-NIR Photoresponse as a Filter-Membrane-Shaped Photocatalyst

The development of effective and reusable photocatalysts with broad-spectra activity has attracted attention.Herein,we have constructed n-TiO_(2)/p-Ag_(2)O junction on carbon fiber(CF)cloth as an efficient and recyclable photocatalyst.With CF cloth as the substrate,TiO_(2) nanorods(length:1-2μm)are prepared by a hydrothermal process,and the in-situ growth of Ag_(2)O nanoparticles(10-20 nm)is then realized by chemical bath deposition route.The flexible CF/TiO_(2)/Ag_(2)O cloth(area:4×4 cm^(2))shows a broad and strong photo-absorption(200-1000 nm).Under the illumination of visible-light(λ>400 nm),CF/TiO_(2)/Ag_(2)O cloth can efficiently eliminate 99.2%rhodamine B(RhB),99.4%acid orange 7(AO7),87.6%bisphenol A(BPA),and 89.5%hexavalent chromium(Cr^(6+))in 100 min,superior to CF/Ag_(2)O cloth(83.5%RhB,60.0%AO7,31.2%BPA and 41.8%Cr^(6+)).In particular,under the NIR-light illumination(980 nm laser),CF/TiO_(2)/Ag_(2)O cloth can remove 70.9%AO7 and 60.0%Cr^(6+) in 100 min,which are significantly higher than those by CF/Ag_(2)O cloth(19.8%AO7 and 18.9%Cr^(6+)).In addition,CF/TiO_(2)/Ag_(2)O cloth(diameter:10 cm),as a filter-membrane,can effectively wipe off 94.4%flowing RhB solution(rate:~1 L h^(−1))at 6th filtering/degrading grade.Thus,CF/TiO_(2)/Ag_(2)O cloth can be used as a Vis-NIR-responded filter-membrane-shaped photocatalyst with high-efficiency for purifying wastewater.

Needle-like cobalt phosphide arrays grown on carbon fiber cloth as a binder-free electrode with enhanced lithium storage performance

Cobalt phosphide(CoP) is a promising anode candidate for lithium-ion batteries(LIBs) due to its high specific capacity and low working potential.However,the poor cycling stability and rate performance,caused by low electrical conductivity and huge volume variation,impede the further practical application of CoP anode materials.Herein,we report an integrated binder-free electrode featuring needle-like CoP arrays grown on carbon fiber cloth(CC) for efficient lithium storage.The as-prepared CoP/CC electrode integrates the advantages of 1 D needle-like CoP arrays for efficient electrolyte wettability and fast cha rge transpo rtation,and 3 D CC substrate for superior mechanical stability,flexibility and high conductivity.As a result,the CoP/CC electrode delivers an initial specific capacity of 1283 mAh/g and initial Coulombic effeciencies of 85.4%,which are much higher than that of conventional CoP electrode.Notably,the Co P/CC electrode shows outstanding cycling performance up to 400 cycles at 0.5 A/cm^(2) and excellent rate performance with a discharge capacity of 549 mAh/g even at 5 A/cm^(2).This work demonstrates the great potential of integrated CoP/CC hybrid as efficient bind-free and freestanding electrode for LIBs and future flexible electronic devices.

Deciphering the lithium storage chemistry in flexible carbon fiber-based self-supportive electrodes

Flexible carbon fiber cloth(CFC)is an important scaffold and/or current collector for active materials in the development of flexible self-supportive electrode materials(SSEMs),especially in lithium-ion batteries.However,during the intercalation of Li ions into the matrix of CFC(below 0.5 V vs.Li/Li+),the incompatibility in the capacity of the CFC,when used directly as an anode material or as a current collector for active materials,leads to difficulty in the estimation of its actual contribution.To address this issue,we prepared Ni_(5)P_(4)nanosheets on CFC(denoted CFC@Ni_(5)P_(4))and investigated the contribution of CFC in the CFC@Ni_(5)P_(4)by comparing to the powder Ni_(5)P_(4)nanosheets traditionally coated on a copper foil(CuF)(denoted P-Ni_(5)P_(4)).At a current density of 0.4 mA cm^(−2),the as-prepared CFC@Ni_(5)P_(4)showed an areal capacity of 7.38 mAh cm^(−2),which is significantly higher than that of the PNi_(5)P_(4)electrode.More importantly,theoretical studies revealed that the CFC has a high Li adsorption energy that contributes to the low Li-ion diffusion energy barrier of the Ni_(5)P_(4)due to the strong interaction between the CFC and Ni_(5)P_(4),leading to the superior Li-ion storage performance of the CFC@Ni_(5)P_(4)over the pristine Ni_(5)P_(4)sample.This present work unveils the underlying mechanism leading to the achievement of high performance in SSEMs.

预应力CFRP布加固混凝土梁受弯试验

目的 研究不同加固方法下预应力碳纤维布加固混凝土梁的受弯性能,解决桥梁加固缺陷的问题。方法 制作了5根试验梁,其中一根为对比梁,不做任何加固处理,其余4根分别采用不同的锚固方式、不同的初始张拉力及不同的加固位置进行加固,通过控制变量,进行加载试验,分析其受弯性能的差异。结果 经加固后的试验梁承载能力与刚度明显增加,与对比梁相比,极限荷载分别提升了25%、22.06%、30.78%及36.76%;各试验梁达到屈服荷载时,经加固的试验梁挠度均小于对比梁产生的挠度,且模腔自锁式锚具锚固的试验梁挠度小于穿孔式自锁锚具锚固的试验梁挠度,相同锚固方法下初始张拉力较大的试验梁挠度要小于初始张拉力较小的试验梁挠度。结论 使用预应力碳纤维布加固混凝土梁能够有效提高混凝土梁的抗弯性能,提升效果与加固位置、锚固方式及初始张拉力大小有关。

浅谈建筑结构加固工艺

我国在基础建设快速发展的阶段,进一步加大了对基础设施建设的投入,从而加快了建筑业的发展,充分发挥国家科技力量的支撑作用,相继修建了各种类型的道路、桥梁、高楼、会展中心、重大水利工程等。由于受到自然灾害、空气影响等,这些建筑的结构往往出现过早老化的情况。据相关统计数据显示,全国城镇需要开展加固工作的民用建筑有30亿平方米,其中亟待修复加固处理的建筑有10亿平方米。如何对这些老旧建筑检测加固,需要进行研究探讨。

碳纤维及碳纤维布混凝土抗冻性及能量耗散试验研究

为探究碳纤维增强方式对混凝土材料抗冻性能及能量耗散影响规律,利用纵波波速仪以及电液伺服压力机获取冻融循环作用(0,25,50,75,100次)后四种混凝土(素混凝土、碳纤维混凝土、碳纤维布混凝土、碳纤维及碳纤维布混凝土)的纵波波速及力学性能,分析碳纤维增强方式、冻融循环次数对试件相对动弹性模量、峰值应力、能量耗散及损伤度影响规律。结果表明:①相较于冻融循环0次素混凝土,冻融循环25,50,75,100次试件相对动弹性模量降幅分别为8.21%、18.33%、30.44%、45.89%,冻融循环次数的增加使试件相对动弹性模量降低,碳纤维及碳纤维布均能减缓试件相对动弹性模量降幅;②冻融循环次数的增加使四种不同混凝土试件峰值应力均呈降低趋势,碳纤维及碳纤维布不仅能够增强试件强度,还能够增强其抗冻性,且两者组合时对试件的提升效果最佳;③相较于未冻融试件,冻融循环25,50,75,100次时弹性变形能降幅分别为3.87%、7.63%、9.67%、12.70%,耗散能降幅分别为10.42%、21.97%、30.16%、41.60%,冻融作用会使试件内部产生损伤,降低试件储能、耗能效果;④三种碳纤维混凝土在达到峰值应力时对应机械损伤度值显著高于素混凝土对应机械损伤度值,碳纤维的增强作用能够有效提升混凝土材料吸能效果、延展性及抗冻性。

抗污型CFC/TiO_(2)光热织物的制备及其在海水淡化中的应用

太阳能光热海水蒸发被认为是解决淡水危机的有效策略,但实际海水中存在油污和有机污染物,长期蒸发过程中污染物会黏附在光热膜表面,致使膜的蒸发性能下降。为实现海水的长期抗污型蒸发,制备兼具光热和光催化性能的碳纤维布(CFC)/TiO_(2)织物。以CFC为衬底,通过水热法在其表面生长TiO_(2)纳米棒阵列(TiO_(2)纳米棒直径约为0.47μm、长度约为1.49μm)。结果显示:CFC/TiO_(2)织物表现出超亲水和超疏油特性,同时具有宽光谱(280~2500nm)光吸收性能(光吸收效率约为88%);在模拟太阳光激发下,CFC/TiO_(2)还可光催化降解有机污染物,如在200min内降解73%的盐酸四环素。将CFC/TiO_(2)光热薄膜构筑成倾斜式海水蒸发器,在模拟阳光(光强为1kW/m^(2))照射下,部分海水被蒸发,蒸发速率达1.68kg/(m^(2)·h),浓缩后的海水在织物底端滴落,长期蒸发不析盐。这种光热/光催化织物有望推动太阳能海水淡化走向实际应用。

轴向荷载作用下碳纤维布约束损伤混凝土能量耗散试验研究

本文对碳纤维布约束损伤混凝土在轴向荷载作用下的力学性能开展试验研究。设计了混凝土损伤度、碳纤维布层数及碳纤维布缠绕角度三种变量,通过试验结果分析了三种变量对碳纤维布约束混凝土应力-应变曲线、峰值应力、耗能效果及机械损伤度的影响规律。试验结果表明:相较于未损伤试件,0.4σm(σm为未损伤混凝土试件单轴抗压强度)、0.5σm、0.6σm、0.7σm应力幅值损伤下素混凝土损伤度均值分别为7.24%、14.86%、25.31%、36.66%,损伤度与损伤应力幅值间指数函数呈现良好的正相关。碳纤维布的约束作用增强试件峰值应力及延性,0.4σm损伤应力作用后,相较于未粘贴碳纤维布试件,粘贴1,2,3层碳纤维布试件峰值应力增幅分别为34.99%、55.16%、64.42%,碳纤维布粘贴层数与峰值应力间指数函数呈负相关,过量的纤维布使试件应力增幅不再明显。碳纤维布缠绕角度的增大使试件单位体积耗散能线性降低,缠绕角度的增大降低了荷载作用下试件的承载效果。应力损伤幅值的增大使试件机械损伤度降低,碳纤维布层数的增加使试件机械损伤度增加,纤维布的约束保护作用极大提升了试件的耗能效果。

装配式PC箱梁负弯矩锚固区加固设计

以某在建桥梁负弯矩区缺少受力钢筋加固设计为例,采用全过程分析方法,对桥梁锚固区承载能力进行验算、并对承载能力不满足工况进行加固处理得出:粘贴钢板和粘贴碳纤维布均能提高桥梁承载能力并满足规范要求,鉴于桥梁加固区为预制箱梁负弯矩锚固区,桥梁成桥后再实施更换加固材料或选择其他加固方法困难,因此在加固材料、方案的选择上需要择优考虑;桥梁设计、施工过程中需重视结构的全寿命周期,减少或者避免建设阶段结构缺陷。

碳纤维加固钢筋混凝土柱受压分析

碳纤维材料的价格有所下降,且碳纤维材料具有强度高、质量低、施工简单、容易操作等特点,因此碳纤维作为一种新型材料在土木工程领域得到了广泛的应用。为了研究碳纤维布加固钢筋混凝土柱后的受压行为,运用ANSYS对钢筋混凝土进行数值分析,比较了未加固钢筋混凝土圆柱与用碳纤维布加固的钢筋混凝土圆柱的抗压强度变化规律以及粘贴不同碳纤维布层数对构件抗压强度有何影响。结果表明:用碳纤维采用全包裹式环向约束法加固过的钢筋混凝土圆柱要比未加固的钢筋混凝土圆柱抗压能力强。钢筋混凝土圆柱的抗压能力随着碳纤维布层数的增加而提高且钢筋混凝土柱抗压能力提高比例在减小。

碳纤维布增强聚丙烯板落锤试验研究

为研究碳纤维布增强聚丙烯板材的抗冲击性能,利用环氧树脂采用外贴的方式分别制备单层碳纤维布和双层碳纤维布的复合板材,同时设置未粘贴碳纤维布的对照组试件,并通过采用INSTRON CEAST 9350落锤冲击试验系统分别以4、8、12 J的能量进行落锤试验,并得出冲击荷载-位移的曲线和试验后板材的损伤破坏形态。试验结果表明,外贴碳纤维布能够显著提高聚丙烯板材的抗冲击性,并且也能够减少聚丙烯板材在冲击荷载下“应力发白”现象的产生,同时粘贴双层的碳纤维布的板材的抗冲击能力优于粘贴单层碳纤维布的板材。

外粘碳纤维布加固混凝土的粘接性能研究

为了提升外粘碳纤维布加固混凝土的粘接性能,对比分析了未掺加钢纤维和掺加不同含量钢纤维的外粘碳纤维布加固混凝土的粘接性能。结果表明,掺加钢纤维可以提升混凝土试件的抗压强度、劈拉强度、极限荷载、峰值扰度和最大应变,从而对混凝土起到加固作用;掺加钢纤维试件的极限荷载要高于未掺加钢纤维的试件,且钢纤维掺加量越大则极限荷载越大,界面滑移也越大;都使用再生骨料混凝土的情况下,掺加钢纤维试件的有效粘接长度大于未掺加钢纤维的试件,且当钢纤维掺加量较大时试件有效粘接长度要高于未使用再生粗骨料的试件。

基于桥梁改造的新旧混凝土结构粘接加固复材改性研究

试验制备了一种聚乙烯醇(PVA)纤维水泥基复合材料(ECC),并将该材料与碳纤维布(CFRP)结合,对新旧钢筋混凝土梁进行复合加固处理,研究材料性能。结果表明,制备的ECC材料具备较好综合性能,粘接效果和抗裂效果良好,可以与CFRP结合,对桥梁混凝土进行粘接加固;相对于普通钢筋混凝土梁,经过ECC/CFRP复合加固后,钢筋混凝土梁的刚度提高,极限荷载明显提升;随着ECC/CFRP复合加固层厚度的增加、CFRP长度的增加,粘接加固效果越好,极限荷载最大值分别达到30.17、29.73 kN。ECC/CFRP复合加固可以提高旧危桥梁混凝土的性能,粘接加固效果较好。