不锈钢基PbO2-WC-CeO2复合镀的机理及镀层性能

不锈钢基PbO2-WC-CeO2复合电极克服了传统钛基二氧化铅(DSA)电极基体易钝化、寿命短和成本高等缺点,以往对其电化学性能研究不多。采用复合电沉积方式在不锈钢基体上制备了PbO2-WC-CeO2复合电极,通过循环伏安曲线(CV)考察了复合电极的电沉积过程;通过X射线衍射(XRD)、能谱分析仪考察了复合电极的元素组成;通过扫描电镜(SEM)考察了复合电极的表面形貌变化;通过Tafel曲线、析氧曲线考察了电极掺杂前后的电化学性能变化。结果表明:WC和CeO2固体颗粒的加入使得PbO2电沉积过程发生了择优生长和晶粒细化,电极耐腐蚀性能提高,催化活性和节能性能变佳。     

表面活性剂对纳米ZnS电极材料电化学性能的影响

采用溶剂热法通过表面活性剂PVP改性所合成纳米ZnS电极材料。XRD、SEM、TEM测试结果表明,经表面活性剂PVP改性后的纳米ZnS结晶度明显提升,具有更完整的晶体结构;并且改性后产物晶粒尺寸更加均一,球形形貌更加完整,团聚现象明显改善。电化学性能测试结果表明,PVP改性后的纳米ZnS负极材料表现出更佳的循环稳定性,其首次可逆比容量可达到557.7 mAh/g,循环50次后可逆比容量仍保持在420 mAh/g,电化学性能明显高于改性前ZnS电极材料。     

改性PbO2 电极电催化降解水中硝基苯酚

为研究PbO2电极的性能,在酸性溶液中,以电沉积法制备了改性钛基PbO2电极,优化并确定了电极的制备工艺,并利用SEM对电极的表面形貌进行了检测.以硝基苯酚为目标有机物,考察了电极的电催化氧化性能.采用铋掺杂PbO2电极处理水中邻硝基苯酚、间硝基苯酚和对硝基苯酚,并对不同硝基苯酚的矿化过程以及降解动力学进行了比较.研究表明:改性PbO2电极的电催化性能优于传统的PbO2电极;邻硝基苯酚在本研究条件下更易被降解.     

AEO改性二氧化铅电极在降解甲基橙过程中的电化学行为

采用阳极氧化法在不锈钢基体上制备了脂肪醇聚氧乙烯醚(AEO)改性PbO2电极。通过SEM图像和XRD图谱分别考察了电极的表面形貌和物相组成,采用稳态极化法和循环伏安法分析了电极在甲基橙模拟废液中的电化学特性,并对质量浓度为10mg·L-1的甲基橙模拟废水进行了电催化降解实验。结果表明,与未改性PbO2电极相比,改性PbO2电极表面平整致密,具有较高的析氧电位和较高的氧化峰电流,有利于有机物的降解。降解实验结果表明改性电极的电催化活性高于未改性电极和石墨电极。     

βPbO2-SPE膜电极材料的制备和性能

将Pb2+络离子交换进入Nafion324基膜内,在碱性条件下通氯气氧化制备出βPbO2-SPE膜电极材料,研究了Nafion324膜的活化、浸渍液中Pb2+的浓度、氧化时间、超声波搅拌强度和氧化温度等参数对βPbO2-SPE电极材料的结构和性能的影响.结果表明,浸渍液最佳组成为0.05 mol·L-1Pb(NO3)2+1 mol·L-1NH4Ac;氧化过程中最适宜超声波搅拌强度为40 W,最佳氧化温度为40℃,氧化时间为2.0 h.在最佳工艺条件下制备的βPbO2-SPE膜电极中活性βPbO2的含量高,βPbO2活性层致密,βPbO2分布均匀,与基膜结合牢固.电化学降解苯酚时βPbO2-SPE膜电极具有比较高的电流效率和电化学稳定性.     

PbO_2-CeO_2电极的制备及其电化学性能

为解决传统铅银合金存在的铅污染和钛基PbO2(DSA)基体易钝化、使用寿命短等问题,以不锈钢为基体,用稀土Ce改性,制备了PbO2-CeO2电极。分析了PbO2的形成机理,通过析氧曲线、Tafel曲线、EDS能谱及扫描电镜考察了温度、电流密度、稀土Ce等对电极性能的影响及所制备电极的元素分布及表面形貌。结果表明:最佳制备工艺为190 g/L Pb(NO3)2,15 g/L Cu(NO3)2,0.5 g/L NaF,30 g/L CeO2,pH值为2～3,机械搅拌,温度70℃,电流密度10～20 mA/cm2,时间30 min;所制备的镀层平整、均匀,电化学性能优良,镀层中CeO2质量分数约为4%～6%;PbO2-CeO2电极析氧电位1 500 mV左右,节能性能明显优于传统惰性阳极。     

PEG/CPB复配改性二氧化铅电极的制备和性能

用电沉积法制备表面活性剂聚乙二醇（PEG）和溴化十六烷基吡啶（CPB）复配改性PbO₂电极,用SEM、XRD、电化学阻抗谱（EIS）和线性极化扫描（VA）等方法对其微结构和电化学性能进行了表征。结果表明,PEG/CPB复配改性在改善PbO₂镀层微结构中产生协同增效作用,使电极表面颗粒进一步细化均匀;复配改性电极明显提升了苯酚的催化降解活性,在2.5 h内对100 mg·L^-1苯酚溶液的降解率为98.7%。PEG/CPB复配改性电极电催化活性的提升与电极的活性表面积增大、电化学反应电阻减小和析氧电位的提高有关。     

聚乙二醇改性钛基PbO_2电极的制备及性质研究

采用电沉积法制备不同浓度聚乙二醇(PEG)改性PbO2电极,通过SEM、XRD等对电极表面形貌和晶相结构进行表征,利用苯酚降解实验考察电极的电催化氧化特性,并进一步通过电化学阻抗谱(EIS)和线性极化扫描(VA)实验考察其电化学性质.SEM和XRD结果表明,PEG可以使电极表面颗粒明显趋于细化,提高β-PbO2的结晶纯度.电化学实验表明改性电极具有更好的电催化活性,更低的界面转移电阻和更高的析氧电位,PEG最佳掺杂浓度为6g/L.苯酚五次连续降解和加速寿命测试实验表明,优化电极具有良好的电催化稳定性,更长的使用寿命和更好的耐腐蚀性.     

TiO2掺杂PbO2电极及其在电解法制臭氧中的应用研究

为了提高电极对臭氧生成反应的电催化活性,采用纳米复合电镀技术制备了TiO2改性PbO2电极.分别采用X射线衍射和X射线荧光光谱分析了其晶体结构和组分含量。将该电极用于电解法制备臭氧,并考察了电流密度、电镀极间距、电镀液pH值以及TiO2颗粒粒径对电极性能的影响.实验结果表明,改性后的PbO2电极使臭氧生成反应的电流效率由11.9%提高到了12.9%.电镀电流密度和电镀极间距的提高有利于提高电极催化活性.TiO2的掺杂会降低PbO2电极的晶胞粒径,有利于提高电极的电催化活性.     

不同基体PbO2镀层电极材料制备的研究现状及展望

PbO2具有良好的电化学性能和耐腐蚀性能,是一种优良的电极材料。综述了近年来不同基体制备PbO2镀层用作电极材料的研究进展及其在降解苯酚、电催化氧化降解甲基橙、锌电积等领域的应用。指出了不同基体PbO2镀层电极材料制备存在的不足和解决问题的初步设想。     

聚乙烯吡略烷酮自组装膜对铜的缓蚀作用

自组装膜对金属防腐蚀有极好的效用。为了进一步弄清聚乙烯吡咯烷酮对铜的缓蚀性能,用自组装技术在铜电极表面制备了聚乙烯吡咯烷酮自组装膜,利用电化学方法研究了自组装膜对铜在NaCl溶液中的缓蚀作用。结果表明,在0.5mol/LNaCl溶液中,随组装时间的增加,铜电极的电荷传递电阻增大,腐蚀电流密度下降,组装24h后对铜的缓蚀效率为99.9%,缓蚀性能优异。     

Study on PVP/C-MMT Nanocomposite Material via Polymer Solution-Intercalation Method

The vinyl polymer/montmorillonite nanocomposite (PVP/C-MMT) was prepared successfully using the way of polymer intercalation from solution. Gel permeation chromatography (GPC) result of PVP showed that polydispersity of PVP was 3.24 with broadly molecule distribution. The results of scan electron microscope (SEM) and thermogravimetry analysis (TGA) showed that the surface of MMT have changed hydrophility into lipophilic and the crystal layer of MMT broken down easily after modified MMT. The result of X-ray diffraction (XRD) and transmission electron microscope (TEM) showed that intercalated nanocomposite was prepared. The pickled sheepskins was tanned with 6% PVP/C-MMT associated with 2% chromate. The application result showed that it is an effective way to decrease use chromate for using nanocomposite.     

石墨烯/银纳米颗粒复合材料的制备及其对双氧水的电化学检测

以氧化石墨烯(GO)和硝酸银为原材料,聚乙烯吡咯烷酮(PVP)为还原剂和稳定剂,通过水热法制备出还原氧化石墨烯/银纳米颗粒(rGO/AgNPs)复合材料。采用透射电子显微镜(TEM)、X射线衍射(XRD)及紫外-可见分光光度计(UV-Vis)对rGO/AgNPs复合材料的形貌、组成和结构进行表征。同时,将rGO/AgNPs复合材料修饰到玻碳电极表面制备出过氧化氢(H_2O_2)电化学传感器,通过循环伏安法(CV)和计时安培响应法(i-t)对传感器进行电化学性能测试。实验结果表明:制备的rGO/AgNPs传感器具有较好的电化学性能,其对H_2O_2检测的灵敏度为340.6μA·(mmol/L)~(-1)·cm~(-2),响应时间为3s,最低检测极限为7.5μmol/L(S/N=3),线性检测范围为20~4950μmol/L(线性相关系数为R=0.9973)。     

Preparation of TiO2 paste using poly(vinylpyrrolidone) for dye sensitized solar cells

The surface morphology of titanium oxide (TiO₂) films as a photoanode in dye sensitized solar cells plays a vital role in converting light to electricity. Therefore, TiO₂ films were prepared using TiO₂ paste with different compositions of poly(vinylpyrrolidone) (PVP) as a binder to optimize their physico-chemical properties. The paste was prepared with commercial TiO₂ powder mixed with acetylacetone, PVP, 4-octylphenol polyethoxylate, acetic acid and ethanol. The chemical composition remains the same for all pastes except PVP. The quantity of the PVP was optimized in such a way that it provides a thick film with a good network connection. The impact of the quantity of PVP in the TiO₂ paste was analyzed. The prepared TiO₂ film structure was characterized by X-ray diffraction. The surface morphology was analyzed by scanning electron microscopy. The electrochemical performance of the prepared TiO₂ as a photoanode was also investigated. Among the four different photoanodes, the cells fabricated with a TiO₂ film prepared with 0.4 g of PVP exhibited the highest power conversion efficiency of 6.77%, short-circuit photocurrent density and open circuit voltage of 12.38 mA/cm² and 0.77 V, respectively.     

Preparation of poly(vinyl alcohol)-based separator with pore-forming additive for lithium-ion batteries

In this work, poly(vinyl alcohol) (PVA)-based separators with microporous structure were prepared from a casting solution composed of PVA resin, water as solvent, and poly(vinyl pyrrolidone) (PVP) polymer as pore controlling additive by non-solvent induced phase separation (NIPS) wet-process and investigated in lithium-ion batteries. The effects of PVP on the morphology and properties of the separator, such as porosity, electrolyte wettability, thermal stability and battery performance (discharge capacity, C-rate capability and cycleability) were systematically analyzed. Results show that PVP induced more pores on the bottom surfaces and the electrolyte uptake, ionic conductivity was further improved. Finally, a 10 wt% PVA-based separator with PVP solid content of 6 wt% exhibited greatly improved porosity, electrolyte uptake, ion conductivity and thermal resistance, resulting in the cell with high safety performance and matched electrochemical performance. The results demonstrated that the PVA-based separator with PVP as pore controlling additive can be a successful candidate serving as an effective separator for lithium-ion battery. Additionally, the present method of producing the microporous separator for LIBs is simple, environmentally benign and economically viable.     

Efficiency Enhancement of Cu（In,Ga）Se2 Solar Cells by Applying SiO2-PEG/PVP Antire flection Coatings

An effective approach was presented to enhance photoelectric conversion efficiency of Cu(In,Ga)Se2 (CIGS) solar cells by using modified SiO2 antireflection coatings(ARCs) to harvest more incident sunlight.Polyethylene glycol(PEG) and polyvinyl pyrrolidone(PVP) used as additives were introduced into silica sols to prepare SiO2-PEG and SiO2-PVP coatings in the sol-gel dip-coating process,respectively. The different effects of PEG and PVP additives on SiO2 coatings were analyzed and the antireflection performance of SiO2-PEG and SiO2-PVP coatings was investigated. The transmittance over 97% ranging from 450 nm to 700 nm with a maximum transmittance over 99.40% at about 550 nm was achieved for both SiO2-PEG2000A and SiO2-PVP0.5 coatings. The relative efficiencies of CIGS solar cells coated with SiO2-PEG2000A and SiO2-PVP0.5 ARCs were increased by 7.27% and 8.33%,respectively. The modified SiO2 ARCs possessed the advantages of the low manufacturing cost,good adhesion,superior antireflective performance and the feasible method for large area fabrication.     

超临界水热制备LiFePO4及煅烧碳包覆改性研究

本文以FeSO_4、H_3PO_4和LiOH为原料,采用超临界水热过程制备了亚微米级LiFePO_4颗粒.在此基础上,为了提升制备的LiFePO_4正极材料的物理和电化学性能,对其进行了后续煅烧碳包覆改性研究.同时,通过XRD、SEM、充放电测试、CV和EIS测试手段,对LiFePO_4正极材料改性前后的结构、形貌和电化学性能进行了表征.结果表明:后续固相煅烧碳包覆改性能够显著改善LiFePO_4的结晶性能,减小颗粒粒径,降低电荷传递阻抗,以及大幅度地提升放电容量和循环性能;以PVP为模板剂、蔗糖为碳源,700℃煅烧1 h得到的LiFePO_4/C颗粒粒径小、分布均一,室温0.2 C倍率的首圈放电比容量为153.1 mAh/g,1 C倍率充放电时,放电比容量可保持在144.2 mAh/g,1 C循环50次,容量保持率达到97.1%.     

Pt nanostructure electrodes pulse electrodeposited in PVP for electrochemical power sources

In this work, we demonstrated that Pt nanostructure electrodes could be obtained by the pulse electrodeposition method in polyvinylpyrrolidone (PVP). The nanocrystal particles were confirmed by scanning electron microscopy, transmission electron microscopy and x-ray diffraction methods. The average size of Pt nanoparticles deposited in additive PVP with low and high molecular weight is 3.4 and 2.9?nm, respectively, whereas that of Pt electrodeposited without PVP is 360?nm. This means that the size of Pt nanoparticles can be controlled by PVP, resulting in an increased electrochemical surface area. The resulting Pt nanostructure electrodes showed such an improved performance for both direct methanol fuel cells and dye-sensitized solar cells.     

磁性纳米钌催化剂的制备及对聚苯乙烯催化加氢的催化性能

通过化学共沉淀法制备了Fe3O4,利用硅酸钠水解、缩合制备了具有核壳结构SiO2/Fe3O4复合纳米粒子。利用红外光谱(FT-IR)、扫描电镜(SEM)、X射线衍射(XRD)以及振动样品磁强计(VSM)技术对其进行了表征。将所得的磁性纳米SiO2/Fe3O4用有机硅改性的聚乙烯吡咯烷酮进行表面修饰,利用原位还原RuCl3的方法将金属Ru负载到磁性载体上,制备了磁性纳米催化剂Ru/PVP/SiO2/Fe3O4。探讨了所得催化剂对聚苯乙烯氢化反应的催化性能,考察了反应压力、温度、时间以及溶剂等对催化性能的影响。结果表明,随着反应温度的升高、压力的增加,催化活性提高;当反应温度为393K、氢气压力为8 MPa、反应时间为5 h时,聚苯乙烯氢化度可以达到90%以上。