少量铟对铅合金在硫酸溶液中阳极行为的影响

采用动电位法研究了纯铅与Pb-0.6%In合金在4 mol/L H_2SO_4溶液中的阳极行为;用X射线衍射仪(XRD)、能谱仪(EDS)和扫描电镜(SEM)分析了阳极极化过程中铅及铅铟合金表面腐蚀层的成分和微观组织结构。结果表明:纯铅及Pb-0.6%In合金电极都存在活化/钝化过渡区,铟的掺入抑制了腐蚀产物层中PbSO_4和PbO的形成,并有利于铅电极表面形成高电化学活性的腐蚀层。因此向铅中添加铟有利于改善铅酸电池的充放电性能。     

Degradation characteristics of Ti/(IrO2+Ta2O5) coating anodes in H2SO4 solution

1　ＩＮＴＲＯＤＵＣＴＩＯＮＴｉｂａｓｅｄＩｒＯ2 ｃｏａｔｉｎｇａｎｏｄｅｓｗｅｒｅｗｉｌｄｌｙｕｓｅｄｉｎｅｌｅｃｔｒｏｃｈｅｍｉｃａｌｉｎｄｕｓｔｒｙｆｏｒｔｈｅｉｒｈｉｇｈｅｌｅｃｔｒｏｃａｔａｌｙｔｉｃａｃｔｉｖｉｔｙａｎｄｓｔａｂｉｌｉｔｙ[1] .Ｉｎａｎｅｘｔｒｅｍｅｃｏｎｄｉｔｉｏｎ ,ｓｕｃｈａｓｈｉｇｈ ｓｐｅｅｄｅｌｅｃｔｒｏｄｅｐｏｓｉｔｉｏｎ ,ｈｏｗｅｖｅｒ ,ｔｈｅｓｔａｂｉｌｉｔｙｏｆＩｒＯ2 ｉｓｎｏｌｏｎｇｅｒｓａｔｉｓｆｉｅｄ .Ｔｈｅｒｅｆｏｒｅ ,ｔｈｅｍｏｄｉｆｉｃａｔ…     

含铝废LiFePO4正极粉在H2SO4溶液中的浸出性能

研究含铝废LiFePO4(LFP)正极粉中LFP和Al的浸出行为及浸出动力学.考察温度(273～368 K)、搅拌速率(200～950 r/min)、反应时间(0～240 min)、酸料比(0.1:1～1:1 mL/g)和液固比(3:1～9:1 mL/g)对浸出过程的影响.结果表明,反应物浓度和温度对Al浸出影响较大....     

铜电积用3D-Pb-Ca-Sn阳极的电化学性能和微观形貌

制备的3D-Pb-Ca-Sn阳极有望成为性能优良的铜电积阳极材料。在160 g/L H₂SO₄溶液中、45 ℃条件下,采用恒流极化、电化学阻抗谱、阳极极化和双斜率Tafel曲线等方法研究了3D-Pb-Ca-Sn和传统Pb-Ca-Sn阳极的电化学性能。此外,还对2种阳极氧化层的微观形貌、元素分布和物相组成进行了研究。结果表明, 3D-Pb-Ca-Sn阳极具有优良的三维通孔结构,增加了阳极的析氧表面积;因此,与传统的Pb-Ca-Sn阳极相比,3D-Pb-Ca-Sn阳极具有更低的阳极电位、更高的交换电流密度和更好的电催化活性,且其氧化层中β-PbO₂含量更高,而PbSO₄含量更低。     

硫酸钠溶液中2024—T3铝合金孔蚀过程的电化学噪声特征

高强度航空铝合金结构材料2024-T3在3.0%（质量分数（Na2SO4溶液中发生局部腐蚀的过程中,电位噪声的谱功率密度（SPD）曲线都具有相同的特征,即在极低频下为白噪声,随着频率的升高逐渐转化为1/f^α噪声,相应于一个噪声信号波,有一个腐蚀孔出现,在孔蚀诱导期,白噪声水平升高,截止频率增大,SPD曲线的倾斜段直线斜率小于-20dBv/decade,且趋于增大,孔蚀发生后,上述3个参量则各自朝着上述方向的塑方向变化,孔蚀时的Hurst指数（H）小于非孔蚀期的Hurst指数,而孔蚀时的系统分维（D）则大于非孔蚀期的系统分维。     

制取活性锌粉的Zn(Ⅱ)-NH3*H2O-(NH4)2SO4体系电解法

研究了在Zn(Ⅱ ) NH3 ·H2 O (NH4 ) 2 SO4 体系中电解制取活性锌粉新工艺。结果表明 :在常温下 ,电流效率高达 88.19%,每吨产品能耗为 32 5 4.37kW·h ,其产品质量符合GB6 890 86标准 ;活性锌粉杂质含量低 ,锌含量≥ 98.78%,有效锌含量≥ 96 %,锌的总回收率为 97.97%。该法与以金属锌为原料的蒸馏法、雾化法相比较 ,成本大幅度降低。     

Controlling limiting length of tunnels on Al foil electroetched in HCl-H2SO4 solution

The limiting length of tunnels, llim, of Al foil electro-etched in HCl-H2SO4 solution and the corresponding anodic polarization curves in the same solution were measured. It is found that there is a dependence of llim on the potential difference, △φ, between the pitting potential, φpit, and the corrosion potential, φcorr, of Al foil, when the temperature and H2SO4 concentration of HCl-H2SO4 electrolyte are changed. The dynamic equation on the tunnel growing and the linear equation between llim and △φ were deduced by analyzing the relationship among the over-potential on Al foil surface, the transport over-potential in tunnel solution and the over-potential at tunnel tip during the electro-etching. The results show that the growing velocity of tunnels decreases with their extending in length and the changing trend of llim can be judged by measuring △φ, which supplies a convenient access to explore new kinds of etchants.     

Pt和PtBi在H2SO4-CH3OH中的氧还原性能

采用氩弧熔炼后热处理方法制备了PtBi金属间化合物材料.采用循环伏安和旋转圆盘电极手段进行电化学性能测试.通过在0.5 mol/L H2SO4 0.25 mol/L CH3OH溶液中对氧还原的起始电位和电流密度大小比较发现,与光滑铂电极相比,PtBi金属间化合物具有良好的氧还原催化性能和抗甲醇中毒性能.从结构方面分析了PtBi具有抗甲醇中毒性能的原因,认为是PtBi中大的Pt-Pt间距不利于甲醇的吸附解离.X射线光电子能谱(XPS)结果表明,PtBi材料中Pt的d电子空穴增加,可能是导致PtBi电极表面氧还原电流增大的原因.     

Al2O3@5A沸石材料制备及其空间分子污染吸附性能

目的 采用原子层沉积技术(ALD)制备了Al2O3@5A沸石分子筛复合材料,以提高材料的综合应用性能。方法 采用三甲基铝为铝源,水为氧源,氮气为载气,工艺压力为26.6 Pa,沉积温度为150 ℃,循环周期为300,在5A沸石分子筛球体表面生长膜厚约为30 nm的Al2O3非晶薄膜,探究Al2O3薄膜对5A沸石分子筛的机械强度和吸附性能的影响。结果 Al2O3薄膜均匀牢度地包覆在5A沸石分子筛表面,有效抑制了分子筛的破裂掉粉。非晶态Al2O3薄膜呈现均匀粗糙的纳米岛状形貌,具有优异的疏水性。此外,Al2O3薄膜提供更多的活性铝,有利于与有机污染物分子发生化学吸附。结论 采用ALD技术制备了形貌均匀、结构致密的Al2O3非晶薄膜,实现了对基底材料5A沸石分子筛的表面改性,不但改善了材料的机械强度和使用稳定性,而且提高了材料对有机污染物的吸附能力。     

锆合金在HCl和H2SO4溶液中的耐蚀性能研究

采用化学浸泡、电化学测试和物理检测技术,研究了HCl和H2SO4溶液中锆合金的腐蚀行为.结果表明,锆合金在还原性的HCl和低浓度H2SO4溶液中,具有优异的耐蚀性,而在高浓度的氧化性H2SO4溶液中腐蚀速率显著增大.物理检测结果显示,腐蚀的锆合金表面均匀地覆盖着弥散分布的微小颗粒状ZrO2.还原性的HCl和低浓度H2SO4溶液中ZrO2膜保持了原有的致密性,增强了锆合金的耐蚀性能.而高浓度H2SO4溶液中,在其强氧化作用下,锆合金基体/膜界面处不断生成ZrO2.当膜增加到一定厚度时,氧化膜的晶格参数与金属的晶格参数不一致,产生内应力,降低了氧化膜的附着力,直至氧化膜破裂,露出新鲜的锆合金表面.继之,新鲜的锆合金再次被氧化,以此循环往复,导致锆合金在浓H2SO4溶液中腐蚀加剧.     

Anodic reaction kinetics of electrowinning zinc in system of Zn(Ⅱ)-NH3-NH4Cl-H2O

The anodic reaction kinetics of zinc electrowinning was investigated on the titanium base RuO2 anode in the system of Zn(Ⅱ)-NH3-NH4Cl-H2O. The effects of stirring speed, ammonium chloride concentration and temperature on anodic reaction rate were studied through the curve measurement of potentiostatic polarization. The results reveal that the electrochemically controlled anodic reaction obeys Tafel equation and the anodic reaction order for ammonium chloride is 1. 056, with the apparent activation energy of 40.17 kJ/mol. The general equation of anodic reaction kinetics was obtained.     

g-C3N4/TiO2纳米管阵列的制备及光催化性能的研究

目的 获得在可见光下光催化活性较好,且可回收、可重复利用的光催化材料。方法 在钛基底上采用阳极氧化法制备TiO2纳米管阵列（TiO2 NTAs）,将TiO2 NTAs在10%尿素溶液中浸渍不同时间后,在氮气保护下高温热分解,制备g-C3N4/TiO2 NTAs复合薄膜。采用XRD、SEM、TEM对复合薄膜进行物相及形貌的表征,在可见光照射下,通过亚甲基蓝溶液的催化降解实验来评估复合薄膜的光催化活性。结果 在10%尿素溶液中浸渍不同时间后所获得的g-C3N4/TiO2 NTAs样品,其可见光催化活性均较纯TiO2 NTAs有所提高,而且随浸渍时间的增加,其可见光催化活性依次增加。浸渍时间为6 h的g-C3N4/TiO2 NTAs样品,在可见光下的光催化活性最高,在120 min内对亚甲基蓝的降解率可达73%。继续增加浸渍时间,所获得的TiO2 NTAs样品的可见光催化活性有所降低。结论 g-C3N4与TiO2 NTAs复合,可以有效提高TiO2 NTAs的光催化活性,其原因是g-C3N4的复合提高了载流子的传递效率,同时也提高了对可见光的吸收。     

Corrosion and wear behaviors of Al-bronzes in 5.0% H2SO4 solution

Steady-state corrosion and wear behaviors of two Al-bronzes, Cu-14Al-X and QAl9-4, in 5.0% H2SO4 solution were investigated. It is found that wear loss of bronzes in 5.0% H2SO4 solution is lower than that in water or in air, namely, it exhibits negative synergy between corrosion and wear. Further analysis shows that corrosive solution plays an important role in cooling of specimen during the sliding wear to prevent the reduction of the surface hardness of specimen, induced by frictional heat. On the other hand, the bronzes suffer a de-alloying corrosion, and a noble copper subsurface and patina form on the specimen surface in corrosive solution, which has a passive function for further corrosion. The noble copper subsurface experiences strain hardening during the corrosion and wear, resulting in the increase of the surface hardness thus the increase in wear resistance.     

Corrosion performance of high pressure die-cast Al-6Si-3Ni and Al-6Si-3Ni-2Cu alloys in aqueous NaCl solution

The corrosion performance of high pressure die-cast Al-6Si-3Ni (SN63) and Al-6Si-3Ni-2Cu (SNC632) alloys in 3.5% (mass fraction) NaCl solution was investigated. X-ray diffraction (XRD) and microstructural studies revealed the presence of single phase Si and binary Al₃Ni/Al₃Ni₂ phases along the grain boundary. Besides, the single Cu phase was also identified at the grain boundaries of the SNC632 alloy. Electrochemical corrosion results revealed that, the SNC632 alloy exhibited nobler shift in corrosion potential (?_corr), lower corrosion current density (J_corr) and higher corrosion resistance compared to the SN63 alloy. Equivalent circuit curve fitting analysis of electrochemical impedance spectroscopy (EIS) results revealed the existence of two interfaces between the electrolyte and substrate. The surface layer and charge transfer resistance (R_ct) of the SNC632 alloy was higher than that of the SN63 alloy. Immersion corrosion test results also confirmed the lower corrosion rate of the SNC632 alloy and substantiated the electrochemical corrosion results. Cu addition improved the corrosion resistance, which was mainly attributed to the absence of secondary Cu containing intermetallic phases in the SNC632 alloy and Cu presented as single phase.     

樟树籽提取物在5%硫酸中对A3碳钢的缓蚀性能影响

采用失重法、极化曲线法、电化学阻抗谱研究了25℃时樟树籽提取物(CCSE)在5%H2SO4溶液中对A3碳钢的缓蚀性能。结果表明,樟树籽提取物为15g/L时,在25℃时缓蚀率达84.01%;因其在钢铁表面吸附起缓蚀作用,吸附模型符合Langmuir吸附等温式;运用相关公式,求出ΔG的值在-20~0kJ/mol之间,属于物理吸附;并讨论了缓蚀机理。极化曲线表明樟树籽提取物是一种混合型缓蚀剂。     

Electrochemical corrosion behavior of plasma sprayed Al2O3‐13%TiO2 coatings in aqueous hydrochloric acid solution

One kind of conventional and two kinds of nanostructured Al₂O₃‐13%TiO₂ coatings were prepared by plasma spray process. The phase composition and microstructure of coatings were examined by means of scanning electron microscopy (SEM) and X‐ray diffraction (XRD). The potentiodynamic polarization and electrochemical impedance spectroscopy (EIS) were used to investigate the corrosion behavior of coatings in aqueous hydrochloric acid solution. The results showed that nanostructured coatings had superior corrosion resistance compared to conventional Metco 130 coating. The corrosion resistance of coatings was mainly related to their microstructure and defects density. The EIS measurement for long time immersion in hydrochloric acid solution revealed that the corrosion resistance of coatings decreased with the increasing of immersion time. During the immersion period, electrochemical corrosion mainly occurred on the carbon steel substrate under NiCrAl coatings. In addition, the Al₂O₃‐13%TiO₂ coatings were also failed during corrosion in aqueous hydrochloric acid solution.     

Synthesis and electrochemical properties of sol-gel derived LiMn2O4cathode for lithium-ion batteries

Spinel LiMn2O4 has been considered to be the most promising alternative cathode material for the new generation of lithium-ion batteries in terms of its low cost, non-toxicity and easy manufacture. The spinel lithium manganese mixed oxides were prepared from lithium nitrate, manganese nitrate and citric acid by asol-gel method and were characterized by thermogravimetric analysis, X-ray diffraction, cyclic voltammetry and constant current charging-discharging technique. The different sintering temperatures for different time have strong influence on the structure, initial discharge capacity and cycling performance of the lithium manganese oxide. It shows that the lithium manganese oxides sintered at 700 ℃ for 10 h have a single spinel structure and better electrochemical properties. The initial discharging capacity can be up to 125.9 mAh·g-1 , even after six cycles, it still retains 109.1 mAh·g-1 .     

3D打印Ti-6Al-4V钛合金表面纳米孔洞制备技术

目的 通过3D打印技术制得钛合金,并构建出微米级多孔粗糙表面,再通过阳极氧化表面处理技术在微米级多孔粗糙表面构建出纳米级结构.方法 首先,通过高压水处理与酸蚀处理相结合的方法,对3D打印钛合金表面进行前处理,去除不良结合的球形粉末颗粒,降低3D打印钛合金表面的粗糙度及各向异性.然后,通过阳极氧化处理,在3D打印钛合金表...     

Preparation and photoelectric effect of Zn2+-TiO2 nanotube arrays

Zn 2+-TiO2 nanotube arrays were prepared by anodic oxidation method.The current-time curves were used to investigate their growth mechanism.Scanning electron microscopy and X-ray diffractometry were applied to characterizing their structures and properties.The photoelectrochemical properties were studied by electrochemical impedance spectrum(EIS).The optimised working conditions for TiO2 nanotube arrays were found to be pH 1,0.5%HF(mass fraction),20 V oxidation voltage and for 2 h.The produced sample was in anatase form,with length of 70-100 nm,thickness of 10 nm,uniform diameter and structure that does not collapse under the preparation conditions.The EIS results show that TiO2 nanotube arrays prepared with 0.5%HF(mass fraction) present a low impedance and TiO2 nanotube arrays loaded by Zn 2+could have a decreased resistance.This decrease could likely accelerate the transfer of carriers and even increase photoelectric conversion.     

CaCl2熔盐中自烧结电解制备粉体Cr3C2及其机制

以氧化铬和石墨粉为原料,采用聚乙烯醇粘接,压制成阴极片,以光谱石墨棒为阳极,在800℃氯化钙熔盐中,恒电压3.2V下,阴极片自烧结电解制备碳化铬.采用XRD、SEM和EDX对样品进行表征.结果表明:粘接的阴极片满足熔盐电解的强度要求,通过熔盐电解过程的自烧结阴极片有效地粘接在一起,并制备出具有良好烧结性能、组分单一的Cr3C2粉体.该法制备Cr3C2的电流效率不低于37.3％.采用恒电位电解法和循环伏安法对电解机制的研究表明,熔盐电解制备Cr3C2的反应机制为:Cr2O3+e→Cr+O2-,Cr+C→Cr3C2两步完成.