强耦合非晶态Sb2S3球与碳纳米管中的钠离子和锂离子存储

A facile one-step strategy involving the reaction of antimony chloride with thioacetamide at room temperature is successfully developed for the synthesis of strongly coupled amorphous Sb₂S₃ spheres and carbon nanotubes (CNTs). Benefiting from the unique amorphous structure and its strongly coupled effect with the conductive network of CNTs, this hybrid electrode (Sb₂S₃@CNTs) exhibits remarkable sodium and lithium storage properties with high capacity, good cyclability, and prominent rate capability. For sodium storage, a high capacity of 814 mAh·g?1 at 50 mA·g?1 is delivered by the electrode, and a capacity of 732 mAh·g?1 can still be obtained after 110 cycles. Even up to 2000 mA·g?1, a specific capacity of 584 mAh·g?1 can be achieved. For lithium storage, the electrode exhibits high capacities of 1136 and 704 mAh·g?1 at 100 and 2000 mA·g?1, respectively. Moreover, the cell holds a capacity of 1104 mAh·g?1 under 100 mA·g?1 over 110 cycles. Simple preparation and remarkable electrochemical properties make the Sb₂S₃@CNTs electrode a promising anode for both sodium-ion (SIBs) and lithium-ion batteries (LIBs).     

单斜相SrAl2Si2O8陶瓷的烧结及其对Sr的固化

Monoclinic SrAl₂Si₂O₈ ceramics for Sr immobilization were prepared by a liquid-phase sintering method. The sintering temperature, mineral phase composition, microstructure, flexural strength, bulk density, and Sr ion leaching characteristics of the SrAl₂Si₂O₈ ceramics were investigated. A crystalline monoclinic SrAl₂Si₂O₈ phase formed through liquid-phase sintering at 1223 K. The introduction of four flux agents (B₂O₃, CaO·2B₂O₃, SrO·2B₂O₃, and BaO·2B₂O₃) to the SrAl₂Si₂O₈ ceramics not only reduced the densification temperature and decreased the volatilization of Sr during high-temperature sintering but also impacted the mechanical properties of the ceramics. Product consistency tests showed that the leaching concentration of Sr ions in the sample with flux agent B₂O₃ was the lowest, whereas that of Sr ions in the sample with flux agent BaO·2B₂O₃ was the highest. These results show that the leaching concentration of Sr ions depends largely on the amorphous phase in the ceramics. Meanwhile, the formation of mineral analog ceramics containing Sr is an important factor to improve Sr immobilization.     

TiB2和Al3Ti对近共晶Al?12.6Si合金组织、力学性能和断裂行为的影响

A near eutectic Al?12.6Si alloy was developed with 0.0wt%, 2.0wt%, 4.0wt%, and 6.0wt% Al?5Ti?1B master alloy. The microstructural morphology, hardness, tensile strength, elongation, and fracture behaviour of the alloys were studied. The unmodified Al?12.6Si alloy has an irregular needle and plate-like eutectic silicon (E_Si) and coarse polygonal primary silicon (P_Si) particles in the matrix-like α-Al phase. The P_Si, E_Si, and α-Al morphology and volume fraction were changed due to the addition of the Al?5Ti?1B master alloy. The hardness, UTS, and elongation improved due to the microstructural modification. Nano-sized in-situ Al₃Ti particles and ex-situ TiB₂ particles caused the microstructural modification. The fracture images of the developed alloys exhibit a ductile and brittle mode of fracture at the same time. The Al?5Ti?1B modified alloys have a more ductile mode of fracture and more dimples compared to the unmodified alloy.     

低氧LiF–NdF3熔盐体系阳极过程的电化学行为研究

The oxidation of oxygen ions and the generation of an anode effect at a low oxygen content of 150 mg/kg were discussed in this paper. Cyclic voltammetry and square-wave voltammetry tests were conducted to explore the anodic processes of LiF–NdF₃ melt after a lengthy period of pre-electrolysis purification at 1000°C (during which the oxygen content reduced from 413 to 150 mg/kg). The oxidation process of oxygen ions was found to have two stages: oxidation product adsorption and CO/CO₂ gas evolution. The adsorption stage was controlled by diffusion, whereas the gas evolution was controlled by the electrochemical reaction. In comparison with oxygen content of 413 mg/kg, the decrease in the amplitude of the current at low oxygen content of 150 mg/kg was much gentler during the forward scanning process when the anode effect occurred. Fluorine-ion oxidation peaks that occurred at about 4.2 V vs. Li/Li+ could be clearly observed in the reverse scanning processes, in which fluorine ions were oxidized and perfluorocarbons were produced, which resulted in an anode effect.     

pH值对β-MnO2颗粒光催化去除银离子的影响

The presence of silver ions (Ag(I)) in wastewater has a detrimental effect on living organisms. Removal of soluble silver, especially at low concentrations, is challenging. This paper presents the use of β-MnO₂ particles as a photocatalyst to remove Ag(I) ions selectively from aqueous solution at various pH levels. Inductively coupled plasma mass spectrometry (ICP-MS), X-ray diffraction (XRD), field emission electron microscope (FESEM), transmission electron microscopy (TEM), and X-ray photoelectron microscopy (XPS) were employed to determine the removal efficiency and to characterize the deposition of silver onto the surface of β-MnO₂ particles. The optimum pH for the removal of Ag(I) ions was at pH 4 with 99% removal efficiency under 1 h of visible light irradiation. This phenomenon can be attributed to the electrostatic attraction between β-MnO₂ particles and Ag(I) ions as well as the suppression of electron–hole recombination in the presence of H+ ions.     

不同温度下CeO2预煅烧对甲醇氧化反应中Pt/CeO2–C电催化剂性能的影响

Pt/CeO₂–C catalysts with CeO₂ pre-calcined at 300–600°C were synthesized by combining hydrothermal calcination and wet impregnation. The effects of the pre-calcined CeO₂ on the performance of Pt/CeO₂–C catalysts in methanol oxidation were investigated. The Pt/CeO₂–C catalysts with pre-calcined CeO₂ at 300–600°C showed an average particle size of 2.6–2.9 nm and exhibited better methanol electro-oxidation catalytic activity than the commercial Pt/C catalyst. In specific, the Pt/CeO₂–C catalysts with pre-calcined CeO₂ at 400°C displayed the highest electrochemical surface area value of 68.14 m2·g?1 and I_f/I_b ratio (the ratio of the forward scanning peak current density (I_f) and the backward scanning peak current density (I_b)) of 1.26, which are considerably larger than those (53.23 m2·g?1 and 0.79, respectively) of the commercial Pt/C catalyst, implying greatly enhanced CO tolerance.     

构建TiO2柱状多层石墨烯纳米复合材料作为降解环丙沙星的高效光催化剂

We successfully constructed TiO₂-pillared multilayer graphene nanocomposites (T-MLGs) via a facile method as follows: dodecanediamine pre-pillaring, ion exchange (Ti4+ pillaring), and interlayer in-situ formation of TiO₂ by hydrothermal method. TiO₂ nanoparticles were distributed uniformly on the graphene interlayer. The special structure combined the advantages of graphene and TiO₂ nanoparticles. As a result, T-MLGs with 64.3wt% TiO₂ showed the optimum photodegradation rate and adsorption capabilities toward ciprofloxacin. The photodegradation rate of T-MLGs with 64.3wt% TiO₂ was 78% under light-emitting diode light irradiation for 150 min. Meanwhile, the pseudo-first-order rate constant of T-MLGs with 64.3wt% TiO₂ was 3.89 times than that of pristine TiO₂. The composites also exhibited high stability and reusability after five consecutive photocatalytic tests. This work provides a facile method to synthesize semiconductor-pillared graphene nanocomposites by replacing TiO₂ nanoparticles with other nanoparticles and a feasible means for sustainable utilization of photocatalysts in wastewater control.     

气体扩散层集流体对Ni(OH)2纳米结构电化学性能的影响

We report the electrochemical performance of Ni(OH)₂ on a gas diffusion layer (GDL). The Ni(OH)₂ working electrode was successfully prepared via a simple method, and its electrochemical performance in 1 M NaOH electrolyte was investigated. The electrochemical results showed that the Ni(OH)₂/GDL provided the maximum specific capacitance value (418.11 F·g?1) at 1 A·g?1. Furthermore, the Ni(OH)₂ electrode delivered a high specific energy of 17.25 Wh·kg?1 at a specific power of 272.5 W·kg?1 and retained about 81% of the capacitance after 1000 cycles of galvanostatic charge–discharge (GCD) measurements. The results of scanning electron microscopy (SEM) coupled with energy-dispersive X-ray spectroscopy (EDS) revealed the occurrence of sodium deposition after long-time cycling, which caused the reduction in the specific capacitance. This study results suggest that the light-weight GDL, which can help overcome the problem of the oxide layer on metal–foam substrates, is a promising current collector to be used with Ni-based electroactive materials for energy storage applications.     

CoO/SnO2@NC/S复合材料的制备及其应用于高稳定性锂硫电池正极材料

To improve the sulfur loading capacity of lithium-sulfur batteries (Li–S batteries) cathode and avoid the inevitable “shuttle effect”, hollow N doped carbon coated CoO/SnO₂ (CoO/SnO₂@NC) composite has been designed and prepared by a hydrothermal-calcination method. The specific surface area of CoO/SnO₂@NC composite is 85.464 m2·g–1, and the pore volume is 0.1189 cm3·g–1. The hollow core-shell structure as a carrier has a sulfur loading amount of 66.10%. The initial specific capacity of the assembled Li–S batteries is 395.7 mAh·g–1 at 0.2 C, which maintains 302.7 mAh·g–1 after 400 cycles. When the rate increases to 2.5 C, the specific capacity still has 221.2 mAh·g–1. The excellent lithium storage performance is attributed to the core-shell structure with high specific surface area and porosity. This structure effectively increases the sulfur loading, enhances the chemical adsorption of lithium polysulfides, and reduces direct contact between CoO/SnO₂ and the electrolyte.     

硫酸溶液中IrO2–ZrO2二元氧化物涂层的电化学行为及耐蚀性

In this study, we prepared Ti/IrO₂–ZrO₂ electrodes with different ZrO₂ contents using zirconium-n-butoxide (C₁₆H₃₆O₄Zr) and chloroiridic acid (H₂IrCl₆) via a sol–gel route. To explore the effect of ZrO₂ content on the surface properties and electrochemical behavior of electrodes, we performed physical characterizations and electrochemical measurements. The obtained results revealed that the binary oxide coating was composed of rutile IrO₂, amorphous ZrO₂, and an IrO₂–ZrO₂ solid solution. The IrO₂–ZrO₂ binary oxide coatings exhibited cracked structures with flat regions. A slight incorporation of ZrO₂ promoted the crystallization of the active component IrO₂. However, the crystallization of IrO₂ was hindered when the added ZrO₂ content was greater than 30at%. The appropriate incorporation of ZrO₂ enhanced the electrocatalytic performance of the pure IrO₂ coating. The Ti/70at%IrO₂–30at%ZrO₂ electrode, with its large active surface area, improved electrocatalytic activity, long service lifetime, and especially, lower cost, is the most effective for promoting oxygen evolution in sulfuric acid solution.     

Effects of Si/Al,Na/Al and H_2O/Na_2O molar ratios on formaldehyde barrier properties of inorganic aluminosilicate coatings

Wood-based panels containing urea-formaldehyde resin result in the long-term release of formaldehyde and threaten human health.In this study, inorganic aluminosilicate coatings prepared by combining metakaolin, silica fume, NaOH, and H_2O were applied to the surfaces of wood-based panels to obstruct formaldehyde release. The Si/Al, Na/Al, and H_2O/Na_2O molar ratios of the coatings were regulated to investigate their effects on the structure and formaldehyde-resistant barrier properties of coatings. Results showed that the cracks in the coatings gradually disappeared and the formaldehyde resistance rates of the barrier increased as the Si/Al molar ratio was increased from 1.6 to 2.2. This value also increased as the Na/Al molar ratio was increased from 0.9 to 1.2 because of the improvement of the degree of polymerization. As the H_2O/Na_2O molar ratio was increased from 12 to 15, the thickness of the dry film decreased gradually and led to the reduction in the formaldehyde resistance rate. When the Si/Al, Na/Al, and H_2O/Na_2O molar ratios were 2.2, 1.2, and 12, respectively, the inorganic aluminosilicate coating showed good performance as a formaldehyde-resistant barrier and its formaldehyde resistance rate could reach up to 83.2%.     

超声/ H2O2工艺降解水溶液中甲醛的实验研究

研究了在超声／H2O2联合作用下，超声场中甲醛的降解过程，考察了超声时间、甲醛浓度、pH值、氧化剂H2O2的浓度等因素对降解率的影响．实验结果表明：甲醛的初始浓度与降解率基本成线性关系；pH值的变化对降解率影响较大，超声波／H2O2联合工艺与单独超声作用相比，降解率有了显著的提高，通常处理100min后，可以获得85％的降解率，其降解过程符合一级动力学方程．     

涂层烧结及热处理工艺对GH2O2合金组织性能的影响

研究了涂层烧结及热处理工艺对GH202合金基材组织性能的影响．运用电子拉伸机、扫描电镜及光学显微镜,测定了拉伸试样的力学性能,并分析了试样的显微组织和拉伸断口．试验结果表明,GH202合金在1150℃固溶处理5h后,合金表面进行高温涂层与烧结,在850℃时效6h出炉空冷,合金基体晶粒细小,均匀;强化相γ弥散分布;合金强度提高,塑性改善,拉伸断口为韧性断裂．     

Ni_3Si涂层对Ti_6Al_4V合金抗NaCl/O_2/H_2O(g)协同腐蚀性能的影响

研究了磁控溅射法制备的Ni3Si涂层对Ti6Al4V合金在600℃下,抗NaCl/氧气/水蒸气协同腐蚀性能的影响.结果表明,在材料遭受腐蚀的过程中,Ni3Si涂层有效地改善了Ti6Al4V合金抗NaCl/氧气/水蒸气综合腐蚀的能力;而无涂层试样遭受了严重的腐蚀,不仅发生了内氧化,而且有大量的腐蚀产物脱落.利用带能谱的扫描电镜、X射线衍射、电子探针和表面光电子能谱对样品的腐蚀行为进行了分析,并讨论了涂层抗腐蚀的机理.     

铅硼硅酸盐玻璃中Al2O3含量对复相玻璃陶瓷性能的影响

以低软化点的铅硼硅酸盐玻璃和Al2O3粉末为原料,制备Al2O3/玻璃低温共烧复合玻璃陶瓷材料。考察烧结温度和添加不同质量分数的Al2O3对复合玻璃陶瓷烧结机制和微波介电性能的影响,并探讨了作用机制。结果表明:Al2O3掺入PbO-B2O3-SiO2玻璃中改善了与Al2O3陶瓷的界面润湿,对烧结有一定的促进作用。在添加质量分数为4%Al2O3的复相玻璃陶瓷、烧成温度为850℃时性能最好,其密度为3.1 g/cm3,介电常数为8.46,介电损耗为0.001 1。     

微弧氧化时间对Ti6Al4V合金表面生物薄膜的影响

为了改善钛合金表面的生物学性能,试验采用微弧氧化的方法在Ti6A l4V合金的表面生成一层富含Ca和P的生物氧化薄膜.研究了在恒流模式下不同氧化时间对膜层的形貌、厚度、元素以及相的组成变化的影响.研究结果表明:随着氧化时间的增加,膜层逐渐变得凹凸不平;膜厚的增速变缓;Ca质量分数呈线性增长;P质量分数呈递减式增长;锐钛矿TiO2的相对含量先增长,然后逐渐减少.     

Effects of BN content on the mechanical properties of nanocrystalline 3Y-TZP/Al2O3/BN dental ceramics

3Y-TZP/3wt％ Al2O3 powder was coated with varying amounts of BN using the urea and borate reaction sintering method, and then multiphase ceramics were prepared by hot pressing sintering. The micro-topography and the compositional analysis of synthesized ceramics were conducted through scanning electron microscopy, transmission electron microscopy and X-ray diffraction. A mechanical tester was used to analyze the Vickers hardness, fracture toughness, and bending strength of the synthesized ceramics. The results showed that the ceramic with a BN content of 12wt％ showed the best processability, but had diminished mechanical properties (such as fracture toughness and bending strength). The ceramic with a BN content of 9wt％ showed better processability than those with 3wt％ and 6wt％ BN. However, the fracture toughness was affected by the addition of 9wt％ BN, making this ceramic only usable as a base material for a three-unit fixed bridge. In con-trast, the ceramics with a BN content of 3wt％ or 6wt％ fulfilled the criteria for use in multi-unit restoration, but their low processability made them unsuitable for milling after sintering.     

钙硅氧化物的质量比对10%Al2 O3高炉渣--尾矿--粉煤灰微晶玻璃性能的影响

利用高炉渣、尾矿和粉煤灰各自成分特点,在未添加任何晶核剂和其他化学试剂条件下,使用烧结法制得了不同CaO/SiO2质量比的10%Al2 O3(质量分数)矿渣微晶玻璃.通过差热分析、X射线衍射、扫描电子显微镜等分析手段,分析了CaO/SiO2质量比和析晶温度对高炉渣-尾矿-粉煤灰微晶玻璃样品的晶相变化规律、析晶行为和主要力学性能的影响.随着CaO/SiO2质量比增大,析晶活化能不断减小,Si-O四面体连接强度下降,质点移动加强,各组开始析晶温度和晶化温度逐渐减小.当玻璃样品中钙硅氧化物的质量比为0.4时,分别在886℃和982℃形核、析晶保温1 h 后,可以得到抗折强度103.59 MPa、显微硬度5.3 GPa、耐酸性0.25%(质量损失率)、耐碱性小于0.1%,主晶相为透辉石的最佳力学性能的微晶玻璃样品.     

CNT-SnO2复合材料的制备及甲醛气敏性的研究

甲醛作为室内装潢最主要的污染物之一,会对人们的健康造成危害。采用旁热式气敏元件的制备工艺,利用功能化后的碳纳米管对二氧化锡进行不同比例的掺杂,利用扫描电镜(SEM)和X射线衍射仪(XRD)对气敏材料进行表征;并在甲醛气氛中与二氧化锡气体传感器进行对比。分析了掺杂浓度,工作温度及气体浓度对传感器灵敏度和响应恢复时间的影响,对其气敏机理进行分析。结果表明碳纳米管的引入提高了二氧化锡传感器对甲醛气体的灵敏度缩短了其响应恢复时间;并且对低浓度的甲醛气体也有较好的响应。     

Reinforcing effect of graphene on the mechanical properties of Al2O3/TiC ceramics

Multilayer graphene (MLG)-reinforced Al2O3/TiC ceramics were fabricated through hot pressing sintering, and the reinforcingef-fect of MLG on the microstructure and mechanical properties of the composites was investigated by experiment and simulation. The simula-tion of dynamic crack initiation and propagation was investigated based on the cohesive zone method. The results show that the composite added with 0.2wt% MLG has excellent flexural strength and high fracture toughness. The major reinforcing mechanisms are the synergistic effect by strong and weak bonding interfaces, MLG pull-out, and grain refinement resulting from the addition of MLG. In addition, the ag-gravating of crack deflection, branching, blunting, and bridging have indispensable contribution to the improvement of the as-designed mate-rials.