Energy storage ability and anti‐corrosion protection properties of TiO2–SnO2 system

TiO₂/SnO₂ and TiO₂–SnO₂ coatings were prepared on type 304 stainless steel by sol–gel method, respectively. TiO₂/SnO₂ coating is compared with TiO₂–SnO₂ coating in terms of energy storage ability and anti‐corrosion property. The two coatings can be charged with reductive energy under UV irradiation in 3 wt% aqueous NaCl. The self‐discharging time of the TiO₂/SnO₂ coating is slower than that of the TiO₂–SnO₂ coating. The slow discharging may be suitable for an anti‐corrosion application for metal. In the case where TiO₂/SnO₂ coating electrode is electrochemically charged at ?0.38 V (vs. SCE) for 1 h, it can maintain a good cathodic protection for type 304 stainless steel for 7 h in the dark, while the TiO₂–SnO₂ coating electrode can only maintain a good cathode protection for 0.5 h in the dark.     

Photocathodic protection properties of NiP/TiO2 bilayer coatings by a combined electroless plating and sol–gel method

A combined electroless plating and sol–gel method was developed for preparing a NiP/TiO₂ bilayer coating to achieve an especial photocathodic protection effect for A3 low carbon steel. Photocathodic protection properties of the coating were investigated by the electrochemical method. Surface morphology and structure of the coating were characterized by scanning electron microscope (SEM) and X‐ray diffraction (XRD). The results show that the open circuit potential (OCP) of the NiP/TiO₂ coating electrode shifts to ?0.42 V under UV irradiation, which is lower than the corrosion potential of A3 low carbon steel. When the light is turned off, the photocathodic protection effect cannot be maintained. In addition, the mechanism of photocathodic protection for the coating was also explored.     

Electrochemical corrosion behaviors and protective properties of Ni–Co–TiO2 composite coating prepared on sintered NdFeB magnet

In this paper, a protective Ni–Co–TiO₂ composite coating was prepared on the sintered NdFeB magnet by direct current electrodeposition. The surface morphologies, microstructure, and chemical composition of the composite coating were studied using scanning electron microscope (SEM), X‐ray diffraction (XRD), and energy dispersive spectroscopy (EDS), respectively. The surface morphologies and microstructure analysis showed that the composite coating possessed cauliflower‐like grain colonies, and formed face‐centered cubic (fcc) solid solution. The electrochemical corrosion behaviors of the composite coating in 0.5 mol/L H₂SO₄, 0.6 mol/L NaOH, 0.6 mol/L Na₂SO₄, and neutral 3.5 wt% NaCl solutions were evaluated by potentiodynamic polarization measurements and electrochemical impedance spectroscopy (EIS), showing good protection for NdFeB magnet. In order to further investigate the protective properties of the composite coating for NdFeB magnet and the practicability of the composite coating, the long‐term immersion test was carried out in neutral 3.5 wt% NaCl solutions using EIS. The results of long‐term corrosion test showed that the Ni–Co–TiO₂ composite coating could provide long‐term protection in neutral 3.5 wt% NaCl solutions for NdFeB magnet.     

TiO2/Al2O3微弧氧化复合涂层的制备及耐磨性研究

本文主要利用微弧氧化方法在Ti-6Al-4V合金表面制备TiO2/Al2O3复合涂层,并揭示了O2-、AlO2-,和Ti4 在涂层生长过程中的作用机制。在高温高电压条件下,Ti-6Al-4V合金表面首先生成TiO2、Al2O3和Al2TiO5,不断放电引起的高热能导致Al2TiO5进一步分解成TiO2和Al2O3,且XRD分析表明涂层的物相组成主要是A-TiO2、R-TiO2和α-Al2O3。耐磨性测试结果表明,与基体相比TiO2/Al2O3复合涂层的显微硬度提高到1100HV,且耐磨性显著提高,磨损量降低了9.5倍。     

Study on hot corrosion behavior of Yb2Zr2O7 ceramic against Na2SO4 + V2O5 molten salts at temperatures of 900–1200 °C in air

Yb₂Zr₂O₇ ceramic powders synthesized by chemical‐coprecipitation and calcination method were pressureless‐sintered at 1700 °C for 10 h in air to fabricate dense bulk materials. Hot corrosion studies were performed on Yb₂Zr₂O₇ against Na₂SO₄ and Na₂SO₄ + V₂O₅ (molar ratio = 1:1) molten salts in a temperature range of 900–1200 °C for 8 h in air, respectively. Chemical reactions were investigated using X‐ray diffraction (XRD) and scanning electron microscopy (SEM). The Yb₂Zr₂O₇ ceramic was severely corroded by Na₂SO₄ + V₂O₅ molten salt, however, no chemical reaction was found between individual Na₂SO₄ and Yb₂Zr₂O₇. Yb₂Zr₂O₇ reacted with Na₂SO₄ + V₂O₅ molten salt to form YbVO₄ and m‐ZrO₂. The thickness of hot corrosion scales formed at different temperatures was investigated to evaluate hot corrosion behavior based on fluxing mechanism. The introduction of vanadium into sulfate led to subsequent formation of NaVO₃, which was acidic enough to dissolve Yb₂Zr₂O₇ by acidic fluxing.     

多元异质结CdS/PbS/TiO2的制备及其对304不锈钢光生阴极保护性能研究

采用阳极氧化法制备TiO₂纳米管,通过超声辅助连续离子沉淀法对TiO₂纳米管进行CdS/PbS共复合修饰改性。应用X射线衍射 (XRD)、扫描电镜 (SEM) 及其配套的能谱分析 (EDS) 对CdS/PbS/TiO₂的晶型特征、表面形貌及元素分布进行表征;利用电化学分析方法研究了复合次序对CdS/PbS/TiO₂的光电性能影响,考察了CdS/PbS/TiO₂复合材料对304不锈钢的阴极保护性能。结果表明:成功制备了晶型特征和表面形貌良好的CdS/PbS/TiO₂多元异质结;先复合9次PbS、再复合15次CdS的TiO₂纳米管具有更加优良的光电性能;光照下CdS/PbS/TiO₂复合材料对304不锈钢光生阴极保护性能显著优于单一PbS复合的TiO₂和纯TiO₂;在暗态下CdS/PbS/TiO₂复合材料储能效果良好,可延长对304不锈钢的阴极保护作用。     

CdSe/石墨烯/TiO_2纳米管复合膜的制备及其对金属的保护性能

采用循环伏安沉积法在TiO2纳米管表面构筑了石墨烯和CdSe,其中TiO2纳米管是由阳极氧化法制备而成。通过扫描电镜(SEM)及能谱(EDS)、X射线衍射分析(XRD)和紫外可见漫反射吸收光谱(UV-vis DRS)等测试方法观察了复合膜的表面形貌、晶型和光响应特征;通过测试可见光照射前后电极的开路电位(OCP)、电化学阻抗谱(EIS)等研究了复合膜对304不锈钢的阴极保护效果。结果表明,锐钛矿相的TiO2纳米管阵列膜排列紧密,孔径约为30~60nm;石墨烯和立方晶相的CdSe均匀地覆盖在TiO2膜表面,在纳米管口与管壁均有分布;可见光照射下,与复合膜耦合的304不锈钢的电位可以从-180mV降至-900mV(SCE),与纯TiO2相比,电位更负。另外,切断电源后,复合膜能够对不锈钢起到延时保护作用并达到12h以上,这说明复合膜能够有效地解决暗态下TiO2光生电子空穴对易复合的问题,改进TiO2对304不锈钢的光生阴极保护效果。     

氧化钒制取碳化钒的热力学分析

采用热力学的方法对以五氧化二钒为原料制取碳化钒的工艺过程进行了分析,分析表明:钒氧化物的转化过程中遵守逐级还原理论。钒氧化物碳化过程中,不转化为金属钒,直接转化为碳化钒。在钒氧化物的转化过程中,应尽可能使其转化为二氧化钒。若采用气相还原碳化的方法,可通过调节气体的流量、配比、还原与碳化工艺参数进行质量控制。     

纳米V2O5薄膜的制备与特性

采用溶胶.凝胶法在Si和普通玻璃基底上制备V2O5纳米薄膜.在空气中对样品进行不同温度的退火处理.利用X射线衍射、扫描电子显微镜和分光光度计对制备的V2O5薄膜的结构、形貌和光学特性进行研究.XRD和SEM研究结果表明:可以通过升高退火温度来提高薄膜的结晶程度、颗粒尺寸及其均匀程度,并增强V2O5的择优取向性.透射谱和吸收谱的研究结果表明:随着退火温度的升高,V2O5薄膜的吸收边缘发生红移,光学带隙逐渐变窄.     

含纳米V2O5颗粒钒催化剂的制备

介绍了1种制备纳米钒催化剂的新方法。用TEM，SEM，XRD，DSC等手段研究了纳米V2O5溶胶．凝胶，以及活性组分V2O5颗粒在钒催化剂中的形貌、大小和分布等。试验结果表明，随着水钒比的降低，纳米V2O5颗粒的形状由针状、椭球状向球状变化：制备纳米V2O5溶胶．凝胶适宜的熔化工艺参数为800℃～860℃，15min～lOmin。采用本工艺方法制备出了含粒径为30nm～60nm的纳米V2O5溶胶-凝胶和纳米钒催化剂。     

Thermodynamic analysis of alloys Ti–Al, Ti–V, Al–V and Ti–Al–V

Thermodynamic analysis of three binary Ti-based alloys: Ti–Al, Ti–V, and Al–V, as well as ternary alloy Ti–Al–V, is shown in this paper. Thermodynamic analysis involved thermodynamic determination of activities, coefficient of activities, partial and integral values for enthalpies and Gibbs energies of mixing and excess energies at four different temperatures: 2000, 2073, 2200 and 2273 K, as well as calculated phase diagrams for the investigated binary and ternary systems. The FactSage is used for all thermodynamic calculations.     

原料和掺杂对钛酸锌陶瓷烧结及介电性能的影响

采用化学法结合传统的氧化物固相烧结法合成钛酸锌(ZnTiO3)粉体,掺杂V2O5作为烧结助剂降低陶瓷的烧结温度,研究了原料活性对钛酸锌陶瓷低温烧结的影响,以及V2O5对钛酸锌陶瓷低温烧结行为和微结构的影响.结果表明钛酸锌陶瓷低温烧结对所选取的原料极为敏感,TiO2对陶瓷烧结影响很大;V2O5有效的将钛酸锌陶瓷的烧结温度从1100℃降到875℃,900℃烧结样品的相对密度达96.1%;同时,V2O5的加入降低了六方相ZnTiO3的分解温度,并导致晶粒异常长大;异相的产生严重影响了陶瓷的介电性能,在微波频段下,900℃烧结掺杂0.75%V2O5(质量分数,下同)钛酸锌陶瓷的Q×f=8873GHz,εr=21.3.     

原料和掺杂对钛酸锌陶瓷烧结及介电性能的影响

采用化学法结合传统的氧化物固相烧结法合成钛酸锌(ZnTiO3)粉体,掺杂V2O5作为烧结助剂降低陶瓷的烧结温度,研究了原料活性对钛酸锌陶瓷低温烧结的影响,以及V2O5对钛酸锌陶瓷低温烧结行为和微结构的影响.结果表明:钛酸锌陶瓷低温烧结对所选取的原料极为敏感,TiO2对陶瓷烧结影响很大;V2O5有效的将钛酸锌陶瓷的烧结温度从1100℃降到875℃,900℃烧结样品的相对密度达96.1%;同时,V2O5的加入降低了六方相ZnTiO3的分解温度,并导致晶粒异常长大;异相的产生严重影响了陶瓷的介电性能,在微波频段下,900℃烧结掺杂0.75%V2O5(质量分数,下同)钛酸锌陶瓷的Q×f=8873GHz,εr=21.3.     

Ti-6Al-4V表面ZrO_2/TiO_2微弧氧化复合陶瓷层的生长特性

研究了Ti-6Al-4V表面ZrO2/TiO2复合陶瓷层的生长规律。采用SEM和XRD分析了氧化时间对陶瓷层的厚度、表面和截面形貌、元素分布和相组成的影响。结果表明:膜层呈现出先快后慢最后趋于平稳的生长动力学,最终膜层厚度44μm。陶瓷膜表面分布着富Zr的陶瓷颗粒,这是由于氧化膜外层的火花放电形成的特征结构。膜层由m-ZrO2、Rutile-TiO2和ZrTiO4组成,Zr元素含量最高可达50.47%。随着氧化时间的增长,膜层表面的Zr含量逐渐降低,m-ZrO2逐渐减少而Rutile-TiO2逐渐增多,并且出现了新相Ti2ZrO6。     

V2O5熔化成膜法制备VO2薄膜

发展了一种新的VO2薄膜制备方法—V2O5熔化成膜法，其基本步骤为：基片预处理—涂粉—熔化成膜—真空退火—VO2薄膜。采用XRD和XPS等手段，对所得薄膜的物相组成与价态进行了分析，同时对薄膜进行了电阻随温度变化的测试。结果表明：通过该方法获得的薄膜，其主要成分是VO2，电阻突变达到4个数量级，相变温度为67．5℃。     

激光重熔双模态Al2O3-TiO2复合涂层的组织与性能

采用普通Metco 130粉末及纳米结构Al2O3-13％ TiO2粉末通过等离子喷涂和激光重熔复合技术分别在Ti-6Al-4V合金表面制备了激光重熔涂层.采用扫描电镜(SEM)和维氏硬度计等手段观察和研究了激光重熔前后涂层的微观组织和硬度.结果表明,激光重熔后,消除了等离子喷涂涂层的层状结构,获得了致密的重熔涂层,且纳米结构重熔涂层传承了喷涂态涂层的双模态组织特征.随着扫描速度的降低,涂层表面的致密度提高.纳米结构重熔涂层的硬度为1150 HV0.3至1750 HV 0.3,比重熔之前的喷涂态涂层约提高了60％.     

Surface Modification of Li1.6(Fe0.2Ni0.2Mn0.6)O2.6 by V2O5- Coating

在采用低温共沉淀-水热-煅烧法合成锂离子电池Fe-Ni-Mn体系正极材料Li1.6(Fe0.2Ni0.2Mn0.6)O2.6的基础上,对合成的材料Li1.6(Fe0.2Ni0.2Mn0.6)O2.6进行V2O5的包覆改性研究,以提高材料Li1.6(Fe0.2Ni0.2Mn0.6)O2.6的首次放电比容量和循环性能。用XRD、SEM、TEM、ICP光谱和恒流充放电测试研究包覆材料的结构和电化学性能。结果表明,V2O5包覆并没有改变材料的晶体结构,只存在于材料的表面,与未包覆的材料相比,V2O5包覆后的材料具有更好的首次放电容量和容量保持率。50周循环后,添加质量分数3%V2O5样品Li1.6(Fe0.2Ni0.2Mn0.6)O2.6的放电比容量可以维持在200.3 mAh/g,大于未添加V2O5样品Li1.6(Fe0.2Ni0.2Mn0.6)O2.6的194.0 mAh/g。CV测试表明,包覆层的存在有效抑制了材料层状结构的转变及电极与电解液的负反应。     

去除Ta2O5/Nb2O5中杂质S的工艺研究

从理论和实际应用方面,研究了去除Ta2O5/Nb2O5中杂质S的方法.通过对制取高纯Ta2O5和Nb2O5的中间产品高纯Ta（OH）5/Nb（OH）3进行过氧化处理,改变Ta,Nb,S等元素在物料中的存在方式,增大了含S杂质的溶解性,降低了物料对含S离子的吸附能力及硫酸盐的分解温度,通过洗涤、焙烧达到有效去除产品中杂质元素S的目的.该方法可在不影响Ta2O5/Nb2O5产品质量的情况下,使杂质S降低到0.0001%以下.     

Self‐healing properties of TiO2 particle–polymer composite coatings for protection of aluminum alloys against corrosion in seawater

TiO₂ particle–polymer composite coatings were applied to the surface of a 5083 aluminum alloy. After using a knife to create an artificial defect, polarization resistance was monitored in artificial seawater at a temperature of 30 °C. The polarization resistance of the specimen coated with the composite polymer containing 3 vol% TiO₂ particles increased significantly over time, suggesting that the composite coating had self‐healing properties. A carbon‐containing 2‐µm thick film was found on the coated aluminum substrate at the site of the artificial defect. The formation of the film was related to the dissolution of bisphenol A (BPA), which is a chemical precursor of the polymer coating that behaved as an inhibiting agent.