Potassium thiocyanate additive for PEDOT:PSS layer to fabricate efficient tin-based perovskite solar cells

The commercialized poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate)(PEDOT:PSS)is usually used as hole transport layers(HTLs)in tin-based perovskite solar cells(TPSCs).However,the further development has been restricted due to the acidity that could damage the stability of TPSCs.Although the PEDOT:PSS solution can be diluted by water to decrease acidity and reduce the cost of device fabrication,the electrical conductivity will decrease obviously in diluted PEDOT:PSS solution.Herein,potassium thiocyanate(KSCN)is selected to regulate the properties of PEDOT:PSS HTLs from the diluted PEDOT:PSS aqueous solution by water with a volume ratio of 1:1 to prepare efficient TPSCs.The effect of KSCN addition on the structure and photoelectrical properties of PEDOT:PSS HTLs and TPSCs have been systematically studied.At the optimal KSCN concentration,the TPSCs based on KSCN-doped PEDOT:PSS HTLs(KSCN-PSCs)demonstrate the champion power conversion efficiency(PCE)of 8.39%,while the reference TPSCs only show a champioan PCE of 6.70%.The further analysis demonstrates that the KSCN additive increases the electrical conductivity of HTLs prepared by the diluted PEDOT:PSS solution,improves the microstructure of perovskite film,and inhibits carrier recombination in TPSCs,leading to the reduced hysteresis effect and enhanced PCE in KSCN-PSCs.This work gives a low-cost and practical strategy to develop a high-quality PEDOT:PSS HTLs from diluted PEDOT:PSS aqueous solution for efficient TPSCs.

Electrochemical potassium ion sensor based on DNA G-quadruplex conformation and gold nanoparticle amplification

A simple, rapid, highly sensitive electrochem-ical sensor for potassium ion （K^＋） based on the confor-mationai change of DNA sequence containing guanine-rich segments is presented. In the presence of K^＋, guanine-rich DNA sequence folds to G-quadruplex structure, allowing a ferrocene tag to transfer electrons to the electrode. Gold nanoparticles （AuNPs）, which are self-assembled on the surface of a bare gold electrode by using 4-aminothio-phenol as a medium, offer a big surface area to immobilize a large number of aptamers and improve the sensitivity of the sensor. The square-wave voltammetry peak current increases with K^＋ concentration. The plots of peak current against K^＋ concentration and the logarithm of K^＋ con- centration are linear over the range from 0.1 to 1.0 mmol·L^-1 and from 1 to 30 mmol·L^-1, respectively. A lower detection limit of 0.1 mmol·L^-1 K^＋ is obtained for AuNPs-modified sensor, which greatly surpasses that （100 mmol·L^-1） of the sensor without AuNPs modification by three orders of magnitude. Thus, the sensor with AuNPs amplification is expected to open new opportunities for highly sensitive detection of other biomolecules in the future.

动物性饲料原料中铁元素含量的快速检测方法研究

研究旨在建立一种利用分光光度法快速检测动物性饲料原料中铁元素含量的方法。采用两种分光光度法(邻菲罗啉法和硫氰酸钾法)对动物性饲料原料灰分中铁元素进行检测。结果显示:试验确定原料中铁元素以Fe^(3+)形式存在,选择硫氰酸钾法作为后续试验的检测方法,优化后硫氰酸钾法的最适条件为:灰化时间3.5 h、检测波长480 nm、硫氰酸钾溶液体积1.0 mL、显色时间10 min、显色反应温度30℃,显色反应过程无须避光。在此参数下测定得到标准曲线在1~20 mg/L范围内具有良好线性关系(R2>0.999 0),方程为y=0.071 5x+0.009(R^(2)=0.999 4)。硫氰酸钾法的稳定性好、准确度高、抗干扰性强,批次内相对标准偏差为1.03%~2.05%,6批次鸡肉粉样品加标回收率为98.02%~101.03%,10~50倍Fe^(3+)浓度的Na^(+)、K^(+)和Ca^(2+)不会干扰Fe^(3+)含量的检测,具有替代原子吸收光谱法进行快速检测的可行性。使用两个方法同时测定11种动物性原料样品中铁元素含量的结果差异不显著(P>0.05)。研究表明,试验建立的硫氰酸钾法可用于宠物食品动物性饲料原料中铁元素含量的快速检测。

血色浪漫

在一些浪漫神奇的魔术背后都隐藏着化学反应。本实验围绕以大众感兴趣的,且与“血色浪漫”相关的神奇现象展开,以简单有趣的几个现象科普化学反应的魅力。其中由硫氰酸钾与铁离子发生络合反应生成血红色絮状络合物,其生成物与氟化钠反应后血红色便会立刻消失,而血红蛋白中的铁可与鲁米诺产生蓝色荧光。在展现这些神奇而浪漫的现象的同时向各个层次人群科普化学知识,解密神奇魔术,探索化学之美,让人们用科学的角度来看待事物,敬佩化学,也充分展示化学的神奇与魅力,有助于激发中小学生和社会大众对化学的探索兴趣与热爱。

基于超声强化硫氰酸盐体系的废旧电路板中贵金属回收研究

电子废弃物中含有大量的稀贵金属,已经成为了重要的城市矿产资源。从电子废弃物中回收贵金属,可以在一定程度上缓解资源短缺问题。目前,对于废旧电路板中金的回收大多采用氰化法,该方法存在严重的环境污染风险。本文提出了一种环境友好、反应速率快的超声强化硫氰酸盐体系用于回收废旧电路板中的金。通过对浸金过程的因子设计和响应曲面设计,建立浸金过程的二阶非线性模型,得到的最佳浸出条件为:硫氰酸钠浓度0.23 mol/L、过氧化氢体积0.96 mL、试验温度41.3℃、固液比188片/25 mL,在此条件下反应90 min,浸金率为94.65%。该体系浸出过程主要受混合模型控制,遵循动力学模型(1-2/3X)-(1-X)^(2/3)+k_(r)/k_(d)(1-(1-X)^(1/3))=kmt。研究成果可为电子废弃物中贵金属资源化回收及其工业化应用提供理论依据。

火试金重量法测定含铋矿物中金、银

建立火试金重量法测定含铋矿物中金银的含量。称取0.50~5.00 g含铋矿物样品,加入硝酸溶液(体积比为1∶1)消解15 min,消解温度为170℃,用活性炭吸附金、硫氰酸钾沉淀银,将吸附金的活性炭和硫氰酸银沉淀置于试金干锅中,加入试金试剂,置于高温电炉中熔融、灰吹、分金,重量法测定含铋矿物中金和银的含量。利用该方法对3个含铋矿物样品进行测定,测定结果的相对标准偏差为0.413%~0.735%(n=7),加标回收率为97.46%~101.90%。该方法适用于含铋矿物中金、银的准确测定。

不同尺寸的AuNPs对废水中污染物的催化降解性能

废水中难降解、强毒性污染物的处理仍是目前亟待解决的问题。金纳米颗粒(AuNPs)具有较大的比表面积、良好的催化活性和生物相容性,在废水处理领域获得广泛的关注。然而,AuNPs的催化活性受颗粒尺寸的影响较大。本文采用化学还原法制备出不同尺寸的AuNPs,并分别对废水中污染物铁氰化钾K_(3)Fe(CN)6和对硝基苯酚(4-NP)进行催化降解以探究AuNPs的催化活性。透射电镜(TEM)和紫外-可见吸收光谱(UVvis)表征结果显示,所制备的AuNPs具有与尺寸相关的催化活性,随尺寸的降低催化活性逐渐增强,4 nm的AuNPs能实现200 s内K_(3)Fe(CN)6和4-NP的快速还原,38 nm以上的AuNPs催化性能较低,且在小尺寸区间,催化活性变化更快。此外,AuNPs循环使用6次后仍保持50%以上的催化活性。

硫酸亚铁铵还原-重铬酸钾返滴定法测定18K金首饰中的金含量

研究了用硫酸亚铁铵还原金,重铬酸钾滴定过剩的硫酸亚铁铵,间接测定18K金首饰中金含量的方法,阐述了样品前处理、不同银铜含量的样品溶解方式,考察了共存元素的影响、方法的准确度和精密度,确定了方法适用范围。

Two Types of Potential Oscillation During the Reduction of Dichromate on Gold Electrode in H2SO4 Solution

Two different types of potential oscillations have been identified for the first time during dichromate reduction on a gold electrode in a solution of dilute sulfuric acid. One occurs before hydrogen evolution due to the formation and dissolution of passivating films of low-valence chromium oxides, and the other generates, accompanying periodic hydrogen evolution, from the coupling of electrochemical reactions with diffusive and convective mass transport. More interestingly, these two types of oscillations correspond to two crossing loops in the cyclic voltammogram （CV）. Such a relation of oscillations with crossed CVs will provide a new way to find electrochemical oscillatory systems systematically and rapidly.

Gold-leaching performance and mechanism of sodium dicyanamide

In this work,sodium dicyanamide(SD)was used as a leaching reagent for gold recovery,and the effects of the SD dosage and solution pH on the gold-leaching performance were investigated.A gold recovery of 34.8%was obtained when SD was used as the sole leaching reagent at a dosage of 15 kg/t.In the presence of a certain amount of potassium ferrocyanide(PF)in the SD solution,the gold recovery was found to increase from 34.8%to 57.08%.Using the quartz crystal microbalance with dissipation(QCM-D)technique,the leaching kinetics of SD with and without PF were studied.The QCM-D results indicate that the gold-leaching rate increased from 4.03 to 39.99 ng·cm^(–2)·min^(–1) when the SD concentration was increased from 0 to 0.17 mol/L,and increased from 39.99 to 272.62 ng·cm^(–2)·min^(–1) when 0.1 mol/L of PF was used in combination with SD.The pregnant solution in the leaching tests was characterized by X-ray photoelectron spectroscopy and electrospray mass spectrometry,which indicated that Au and(N(CN)2)–in the SD solution formed a series of metal complex ions,[AuNax(N(CN)2)x+2]–(x=1,2,3,or 4).

Studies on the Gold-Coated Electrode with Grid

Introduction Thin-layer spectroelectrochemical method has many unique advantages, therefore this method has been widely applied and developed. Recently light transparent thinlayer spectroelectrochemical cells with various types of structures have been reported at home and abroad with gold or platinum minigrids as the working electrode in most of

电沉积法从硫氰酸盐浸金液回收金的试验研究

针对硫氰酸盐浸金液金回收效率低且成本高等问题,利用电沉积法从硫氰酸铵浸金液中回收金。采用单因素法研究了阳极材料、阴极材料、极间距、槽电压、溶液pH值和温度对金沉积率的影响,结果表明:以石墨棒作阳极、自制电极作阴极,在极间距为10 mm、槽电压为4 V、溶液pH=12和温度为35℃的条件下,电解2 h,金沉积率达到98.95%。采用响应面法研究了槽电压、溶液pH值与溶液温度之间的交互作用及其对金沉积率的影响,结果表明:各因素对金沉积率的影响程度依次为槽电压>溶液pH值>溶液温度,并建立了电沉积金响应面回归模型。在槽电压为4.10 V、溶液pH=12.40和温度为39.58℃的最佳条件下,模型预测值为99.06%,试验平均值为99.04%,二者结果非常接近,证明该模型能够对金沉积率进行准确的分析预测。本研究进一步完善了硫氰酸盐提金工艺理论体系。

亚硫酸钠-柠檬酸钾体系络合剂对镀金层性能的影响

目的 研究亚硫酸钠-柠檬酸钾体系络合剂对可伐基板镀金层共晶焊接性能的影响机理,从而优化络合剂含量工艺范围,提升镀金层金锗共晶可焊性。方法 采用扫描电子显微镜及能谱仪(SEM-EDS)、X射线衍射仪(XRD)、极化曲线等分析方法,结合镀金层孔隙、金锗共晶焊接润湿性和剪切强度测试,研究了亚硫酸钠-柠檬酸钾体系络合剂,对镀金层表面金锗焊料润湿性,金锗共晶层结合力、表面和截面形貌、结晶状态、孔隙,以及金锗共晶焊接界面微观形貌等的影响。结果 亚硫酸钠和柠檬酸钾均能起到络合剂作用,当络合剂亚硫酸钠质量浓度为120~160 g/L和柠檬酸钾质量浓度为40~60 g/L时,络合剂含量的增加可使镀金液阴极过电位明显增大,从而使所制备的镀金层结晶更加致密。当络合剂亚硫酸钠质量浓度为160~200 g/L、柠檬酸钾质量浓度为60~100g/L时,电沉积的镀金层表面明显平整,截面形貌致密,孔隙少,且以(311)晶面择优生长,晶粒尺寸为43.7nm,晶面间距为0.123nm,金锗焊料润湿良好,金锗共晶层结合力较大,剪切强度可达3 MPa以上,可满足金锗共晶焊接使用要求。结论 亚硫酸钠-柠檬酸钾体系络合剂含量对镀金层的结晶状态和致密性影响明显,镀金层结晶状态和致密性与其表面金锗共晶可焊性有直接关系,镀金层越结晶致密越有利于其表面共晶焊接质量,通过控制亚硫酸钠-柠檬酸钾络合剂含量可有效提高镀金层表面金锗共晶焊接质量。

STUDIES OF UNUSUAL OXIDATION STATES OF TRANSITION METALS (Ⅰ)——KINETICS AND MECHANISM OF OXIDATION OF POTASSIUM THIOCYANATE BY DIPERIODATOARGENTATE(Ⅲ) ION IN ALKALINE MEDIUM

The kinetics of oxidation of potassium thiocyanate by diperiodatoargentate (Ⅲ) (DPA) ions was studied in aqueous alkaline medium ([OH^-]=7.00×10^(-3)—0.200 mol. dm^(-3)) at a constant ionic strength (μ=0.30 mol. dm^(-3)). It is found that the reaction order in DPA is unity. The dependence of the rate on [OH^-] implies that there are two pathways through which the reaction proceeds. In each pathway, the order in NCS-is fractional and the kinetic data fit well in with Michaelis-Menten process. The influence of ligand on the reaction is examined and the reactive species are inferred. Two pathways of inner-sphere two-electrons transfer are believed to be involved in the oxidation. The rate equations are derived and all the equilibrium constants and rate constants are evaluated. Activation parameters of one pathway are determined.

Gold Nanoclusters Templated by Poly-cytosine DNA as Fluorescent Probes for Selective and Sensitive Detection of Thiocyanate

Gold nanoclusters(AuNCs) were prepared in the presence of the nucleobases of poly-cytosine DNAs in this paper. We have demonstrated tliat the fluorescence of the AuNCs is quenched by thiocyanate(SCN^-) through the interaction between SCN^- and gold atoms. AuNCs can receive energy from nucleobases to boost their emission intensity, while in the presence of SCN^-, they coordinate with Au atoms and influence the energy transfer between the nucleobases and AuNCs, leading to the fluorescence quenching. The decreased fluorescence intensity was in proportion to the concentration of SCN^- in the range of 8.0×10^-7-1.5×10^-5 mol/L with a limit of detection of 4.2×10^-7 mol/L(3σ). We further validated the practice of this probe througli the detection of SCbT in natural water samples.

Simulating ion clustering in potassium thiocyanate aqueous solutions with various ion-water models

Using a molecular dynamics simulation technique,we compared several commonly used ion-water models to describe the microscopic structures and dynamics in KSCN aqueous solutions.Results are compared with observations of femtosecond infrared vibrational-energy transfer and anisotropy measurements.The Jorgensen/TIP4P model is found to provide the best reproduction of clustering properties such as percentage of clustered ions,cluster-size distribution,concentration dependence of the water,and ion-rotation time constants.

硫氰酸钾—自动电位滴定法测定锡铋银系列无铅焊料产品中银含量

文章对硫氰酸钾-自动电位滴定法,测定锡铋含银系列无铅焊料产品中银量的各项操作条件进行了试验,研究了锡铋含银产品的分解、主要共存元素对测定银的干扰试验。对方法的准确度和精密度进行了考察,结果稳定,重现性好,适合于锡铋含银产品中0.3%~2.0%银的测定。

THE MOLECULAR AND CRYSTALLINE STRUCTURE OF POTASSIUM 18-CROWN-6 WITH COBALT (Ⅱ) THIOCYANATES

Ⅰ. INTRODUCTION This paper reports on the coordination compound grown in a gel by reaction of 18-crown-6 with cobalt (Ⅱ) chloride and potassium thiocyanate. The composition of this coordination compound was determined by elemental analysis while the functional groups in the molecule were studied with IR. The molecular and crystalline

无汞法测定金精矿全铁含量最优条件探索

目前金精矿中全铁含量的测定标准方法为氯化亚锡还原-二氯化汞-重铬酸钾容量法,此法由于环保和试剂管控的要求给企业带来困扰。本文通过实验对比发现:三氯化钛还原-硫酸铜催化-重铬酸钾容量法相对于其他无汞法测定较为精准,同时探讨了此法的分解用酸、硅酸盐包裹消除、过量三氯化钛消除方式、干扰消除等问题,调整后方法相对标准偏差为0.13%~0.21%,准确度和精密度较高,且具有操作简单快速、成本低等优势,适合批量样品测定。

硫脲-硫氰酸钠浸出难处理金矿及浸出剂的稳定性

采用高温焙烧、硫脲-硫氰酸钠浸出难处理金矿中的金,研究焙烧温度、硫氰酸钠浓度、硫脲(Tu)浓度、Fe3+浓度、pH值、浸出温度和时间对金浸出率的影响,得到混合体系浸金的最优条件,并研究浸出过程中硫氰酸钠和硫脲的稳定性。结果表明:金的浸出率达到93.1%,超过相同条件下单一体系中的浸出率之和,硫脲与硫氰酸钠摩尔比对金浸出率和金电极稳定电位影响较大;硫氰酸钠使硫脲的稳定性降低,而硫脲使硫氰酸钠的稳定性增强。