扫描电化学显微镜瑞士万通学习报告课件

1、扫描电化学显微镜瑞士万通学习报告,1,Scanning Electrochemical Microscopy 扫描电化学显微镜,扫描电化学显微镜学习总结 张富纬 2016.9.17,扫描电化学显微镜瑞士万通学习报告,2, ,A small probe is scanned in short distance over a sample surface and a characteristic property of the sample is detected. Interaction of probe and sample! 其原理是在样品短距离的表面上，通过探针与样品的相互作用 并检测到样

2、品的特征属性。 扫描探针技术有 STM, AFM, SNOM, SECM Scanning electrochemical microscopy (SECM) is the only technique able to detect(electro-) chemical reactions. SECM是唯一一种能够检测（电）化学反应的扫描探针技术。 Resolution depends on the tip size!,SECM Classification SECM归类于扫描探针技术 Scanning probe techniques:,3,扫描电化学显微镜瑞士万通学习报告,3,Basic

3、Setup 下图是整个仪器的形貌,4,扫描电化学显微镜瑞士万通学习报告,4,4,这是与SECM连用的电化学工作站,这是SECM的工作池也就是放样品的区域（长宽高大概为2*2*1cm）,SECM目前只能在小样品（1cm左右），平面上做一些基础性研究使用。,扫描电化学显微镜瑞士万通学习报告,5,Imaging Modes,5,SECM的这些工作模式基底都是不通电的，这是原来理解上的一个误区。这个误区 在下面反馈模式中的正反馈中给本人和万通中国的人都造成了误解。正反馈是由于基 底为导体由于导体与探针之间的相互作用导致了电流的增大。 其关于电流密度的扫描是通过一定电镀时间的间隔下对被镀件表面进行扫描通

4、过哪 里沉积的多少来实现的。,扫描电化学显微镜瑞士万通学习报告,6,Imaging Modes Negative Feedback,A reversible redox species is required !,6,扫描电化学显微镜瑞士万通学习报告,7,Imaging Modes Positive Feedback,7,由于基底不通电所以检测基底活性是SECM都是采用的可溶解的 氧化还原电对（如Fe3+/Fe2+）。,扫描电化学显微镜瑞士万通学习报告,8,Feedback Mode - Measurement Conditions,Calculated approach curves wit

5、h RG=10 according to J. L. Amphlett et al., J. Phys. Chem. B 102 (1998), 9946,8,扫描电化学显微镜瑞士万通学习报告,9,Feedback Mode,9,扫描电化学显微镜瑞士万通学习报告,10,Array Scan for Surface Mapping,x,y,data point,individual line of array scan,10,扫描电化学显微镜瑞士万通学习报告,11,Feedback Mode,Visualization of electrochemical activity distributi

6、on on a sample surface.,11,扫描电化学显微镜瑞士万通学习报告,12,Feedback Mode - Example,Ru3+ Ru2+,itip,-400 mV,12,扫描电化学显微镜瑞士万通学习报告,13,Feedback Mode - Example Differences in local electrochemical activity e.g. due to surface impurities.,General goal of SECM studies is the determination of the electron-transfer kineti

7、cs at the sample surface!,13,扫描电化学显微镜瑞士万通学习报告,14,Generator/Collector Mode (GC Mode),14,扫描电化学显微镜瑞士万通学习报告,15,Generator/Collector Mode - Example,15,扫描电化学显微镜瑞士万通学习报告,16,Comparison Feedback and GC Mode,5 mM Ru(NH3)63- in 100 mM KCl, RE: Ag/AgCl (3 M KCl), for GC: WE1: 2nd band Esample = -400 mV, WE2: 25

8、m Pt tip,Ru2+,Ru3+,0 mV,Ru3+,Ru2+,Ru3+,Ru2+,-400 mV,16,扫描电化学显微镜瑞士万通学习报告,17,Comparison Feedback and GC Mode,5 mM Ru(NH3)63- in 100 mM KCl, RE: Ag/AgCl (3 M KCl), for GC: WE1: 2nd band Esample = -400 mV, WE2: 25 m Pt tip,+ sensitivity lateral resolution (diffusion profiles) time dependency,+ lateral r

9、esolution high background current redox mediator required,17,扫描电化学显微镜瑞士万通学习报告,18,Practical Training SECM,18,Fe2+ Fe3+,500 mV,扫描电化学显微镜瑞士万通学习报告,19, Local experiments due to mobile electrochemical cell Standard EC (OCP detection, polarization curves etc.) possible Only small area of samples is in conta

10、ct with electrolyte, exchange of solution prior to each new grid point,RE,CE,Electrolyte WE,19,对于我们公司这种大且形状复杂的产品，Thomas给出了一下Cell的解决方案 不过这是一种全新的技术，其液滴口直径也不超过1mm，基本无工业化应用价值。,Scanning Droplet Cell SDC,扫描电化学显微镜瑞士万通学习报告,20,Scanning Droplet Cell Option SDC, ,Local experiments due to mobile electrochemical

11、 cell Standard EC (OCP detection, polarization curves etc.) possible Only small area of samples is in contact with electrolyte Photoelectrochemistry,RE,CE,Electrolyte inlet 20,扫描电化学显微镜瑞士万通学习报告,21,SECM Applications SECM 的应用领域,扫描电化学显微镜瑞士万通学习报告,22,Application,SECM is always useable when the local effec

12、ts determine the property of the whole material (global appearance). SECM主要是通过研究材料的局部反应来判断材料的整体性能。,2,扫描电化学显微镜瑞士万通学习报告,23,Fields of Application,3,腐蚀,催化剂,燃料电池,表面修饰,与我们公司关联性较大的主要就是腐蚀不过其主要是 用于单层涂层的耐蚀性研究。对于电镀产品而言此功能 通过电化学工作站的阻抗分析也可以实现。,扫描电化学显微镜瑞士万通学习报告,24,Reactivity on Stainless Steels 304 and 316,J. Izq

13、uierdo et al., Electrochimica Acta 134 (2014), 167,Stainless Steel 316,Stainless Steel 304,0.5 h,4h,7.5 h,24 h,0.5 h,3h,4,Distribution of iron (II) ions 0.25 M HCl (GC-Mode),扫描电化学显微镜瑞士万通学习报告,25,O2,O2,O2,O2,O2,Corrosion of Steel Oxygen Competition E, i iT,E Consumption of Oxygen is traced Variation o

14、f GC-mode J. J. Santana et al., Electrochim. Acta 55 (2010), 4488 5,扫描电化学显微镜瑞士万通学习报告,26,Corrosion Protective Coatings,R. G. Duarte et al., Prog. Org. Coat. 74 (2012), 365,PVC Plastisol coated nickel,foils and 0.5 mM,ferrocene- methanol.,Insulator as,sample surface Topography,6,扫描电化学显微镜瑞士万通学习报告,27,Co

15、rrosion Protective Coatings,J. Izquierdo et al., Prog. Org. Coat. 74 (2012), 526,2-mercaptobenzimidazole,SECM image recorded in measuring solution of,0.1 M Na2SO4 + 1 mM,ferrocenemethanol,7,扫描电化学显微镜瑞士万通学习报告,28,E. Martinez-Lombardia et al., Electrochim. Acta 116 (2014), 89,5 mM ferrocenemethanol,Corr

16、osion - Copper Image with passive layer Effects due to crystallographic orientations of copper Image after removal of passive layer,8,扫描电化学显微镜瑞士万通学习报告,29,Dissimilar Weld,J. Jayaraj et al., J. Adv. Microsc. Res. 7 (2012), 214,Tip reaction at 1.5 V:,HNO3 + 2H+ 2e- HNO2 + H2O,9,扫描电化学显微镜瑞士万通学习报告,30,Self

17、-healing Coatings,A. Pilbth et al., Prog. Org. Coat. 75 (2012), 480,Detection of Fe2+,Detection of O2,Microcapsules with linseed oil mixed,into epoxy resin coating.,10,扫描电化学显微镜瑞士万通学习报告,31,Catalysis,11,扫描电化学显微镜瑞士万通学习报告,32,Pt on C support (E-tek),Vulcan XC-72R,Printex L6,Catalysis Fuel Cells Oxygen Re

18、duction Reaction ORR in alkaline solution, effect of carbon support H2O2 detection,M. H. M. T. Assumpo et al., Carbon 49 (2011), 2842 12,扫描电化学显微镜瑞士万通学习报告,33,Electrocatalytic Activity of Carbon Fiber,Investigation of a single strand of carbon fiber.,3 mM -methyl ferrocene methanol in phosphate buffer

19、,Pseudo first order rate constant via approach curves V. S. Joshi et al., J. Phys. Chem. C 116 (2012), 9703 13,扫描电化学显微镜瑞士万通学习报告,34,Membrane Transport,Transport phenomena in channels / membranes / pores,14,扫描电化学显微镜瑞士万通学习报告,35,Diffusion through Membranes for Gas Sensors,M. Nebel et al., Electrochim. A

20、cta 55 (2010), 7923,15,扫描电化学显微镜瑞士万通学习报告,36,Life Sciences - Biodegradable Material,M. D. Pereda et al., Acta Biomater. 6 (2010), 1772,16,扫描电化学显微镜瑞士万通学习报告,37,Material Science Reduced Graphene Oxide on Fabrics,J. Molina et al., Appl. Surf. Sci. 279 (2013), 46,17,扫描电化学显微镜瑞士万通学习报告,38,Biosensors,Biosensor

21、 characterization,18,扫描电化学显微镜瑞士万通学习报告,39,GC and RC-SECM for Biosensors,I. Morkvenaite-Vilkonciene et al., RSC Adv. 4 (2014), 50064.,19,扫描电化学显微镜瑞士万通学习报告,40,Cellular Activity,Release or consumption,20,扫描电化学显微镜瑞士万通学习报告,41,Respiration Activity,d, t = 15 ms,Topography,M. Nebel et al. Angew. Chem. Int. Ed

22、. 52 (2013) 6335 21,扫描电化学显微镜瑞士万通学习报告,42,Intra- and Extracellular Redox Processes Yeast Cell,I. Morkvenaite-Vilkonciene et al., Sensors and Actuators B: Chemical 228 (2016), 200,22,扫描电化学显微镜瑞士万通学习报告,43,SECM Advanced Detection Modes SECM 前沿的检测方法,扫描电化学显微镜瑞士万通学习报告,44,AC-SECM 阻抗-SECM联用技术, All advantages o

23、f frequency,dependent response, No redox mediator necessary Diluted solution possible,Impedance spectra at each point of the scanned grid,measured at the tip in close distance to the sample surface.,2,扫描电化学显微镜瑞士万通学习报告,45,AC-SECM,RE,CE,non-conductive,B. Ballesteros Katemann, A. Schulte, E. J. Calvo,

24、M. Koudelka-Hep, W. Schuhmann, Electrochem. Commun. (2002), 4 134,A. S. Baranski, P. M. Diakowski, J. Solid State Electrochem. (2004), 8, 683 K. Eckhard, T. Erichsen, M. Stratmann, W. Schuhmann, Chem. Eur. J. (2008), 14, 3968,RCt,Cdl,RS,RCt,Cdl,RS,RSt,RSs,RP1,RP2,CP1,CP2,conductive sample,Rct Cdl Rs

25、 RP,= = = =,charge transfer resistance double layer capacitance solution resistance polarization resistance (sample),3,扫描电化学显微镜瑞士万通学习报告,46,AC-SECM,RE,CE,RE,CE,Cdl,RS,RCt,Cdl,RS,RSt,RSs,RP1,RP2,CP1,CP2,constant,No faraday prozess,A. S. Baranski, P. M. Diakowski, J. Solid State Electrochem. (2004), 8,

26、 683 K. Eckhard, T. Erichsen, M. Stratmann, W. Schuhmann, Chem. Eur. J. (2008), 14, 3968,No faraday prozess RCt,non-conductive RS increases during approach,conductive sample alternative path through sample,4,扫描电化学显微镜瑞士万通学习报告,47,Z/Z,AC-SECM,1 mM KCl, RE: Ag/AgCl, Ampl. 10 mV,RCt,Cdl,RS,RSt,RSP,RP1,RP

27、2,CP1 shortcut,CP2,Rct Cdl Rs RP,= = = =,charge transfer resistance double layer capacitance solution resistance polarization resistance (sample),0,8,0,1,3 2,Glass,0.5 kHz,Glass Platinum Platinum,6 kHZ 0.5 kHz 6 kHz,4 L = d/r,5,扫描电化学显微镜瑞士万通学习报告,48,Comparison LEIS and AC-SECM E WE,5-electrode configu

28、ration LEIS: Global AC perturbation at sample, measurement of local AC current density to calculate local impedance.,3-electrode configuration AC-SECM: AC perturbation directly at tip electrode and interaction underneath measured, uses SECM tips (much smaller tips resolution) 6,扫描电化学显微镜瑞士万通学习报告,49,H

29、igh resolution imaging in SECM 成像技术,扫描电化学显微镜瑞士万通学习报告,50,Resolution in SECM, Tip size (ratio of the size of tip and structure) Distance between data points (step size) Working distance (contrast), Detection mode and RG value of tip,*Ratio of overall electrode radius to the radius of the active tip su

30、rface,2,扫描电化学显微镜瑞士万通学习报告,51,Fe2+ Fe3+,itip,500 mV,3,扫描电化学显微镜瑞士万通学习报告,52,Resolution in SECM Effect of Tip Size,5 mM Fe(CN)64- in 100 mM KCl, RE: Ag/AgCl (3 M KCl), Etip = +500 mV, Feedback mode,25 m Pt tip Increments: x = 12.5 m, y = 25 m Working distance: 25 m,10 m Pt tip Increments: x = 5 m, y = 10

31、 m Working distance: 10 m,4,扫描电化学显微镜瑞士万通学习报告,53,Resolution in SECM Effect of Tip Size,Interaction area,depends on tip size,Signal averaged over tip size,5,扫描电化学显微镜瑞士万通学习报告,54,Resolution in SECM Effect of Tip Size,25 m Pt tip Increments: x = 12.5 m, y = 10 m Working distance: 12.5 m 5 mM Fe(CN)64- in

32、 100 mM KCl, RE: Ag/AgCl (3 M KCl), Etip = +500 mV,10 m Pt tip Increments: x = 5 m, y = 10 m Working distance: 5 m,6,扫描电化学显微镜瑞士万通学习报告,55,Resolution in SECM - The Parameter Step Width,d,r,Fast experiment, no loss of information. Max. of information and well resolved graphs. No additional information

33、BUT increase of the exp. duration. Loss of information (dotted lines) but fast experiments. 7,扫描电化学显微镜瑞士万通学习报告,56,Resolution in SECM Effect of Step Width,5 m 12.5 m,2 m 50 m,10 m Pt tip, working distance 5 m, 10 m y-increment, 5 mM Fe(CN)64- in 100 mM KCl, RE: Ag/AgCl (3 M KCl), Etip = +500 mV,8,扫描电

34、化学显微镜瑞士万通学习报告,57,I = i / i,0,2,4,6,8,10,3 2 1 0,4,L = d/r,1,2,10 m Pt tip,12.5 m x-increment, 10 m y-increment, 5 mM Fe(CN)64- in 100 mM KCl, RE: Ag/AgCl (3 M KCl), Etip = +500 mV,WD 25 m (5r),WD 5 m (r),Working distance determines contrast!,9,扫描电化学显微镜瑞士万通学习报告,58,Resolution in SECM EC determines the

35、 resolution! The choice of the electrode size and the parameter step width (distance between data points) is crucial. d r,The positioning system has a sufficient repeatability (bidirectional 15 m stepper motors and 10 nm piezo system).,10,扫描电化学显微镜瑞士万通学习报告,59,Comparison Feedback and GC Mode,5 mM Ru(N

36、H3)63- in 100 mM KCl, RE: Ag/AgCl (3 M KCl), for GC: WE1: 2nd band Esample = -400 mV, WE2: 25 m Pt tip,Ru2+,Ru3+,0 mV,Ru3+,Ru2+,Ru3+,Ru2+,-400 mV,11,扫描电化学显微镜瑞士万通学习报告,60,Comparison Feedback and GC Mode,5 mM Ru(NH3)63- in 100 mM KCl, RE: Ag/AgCl (3 M KCl), for GC: WE1: 2nd band Esample = -400 mV, WE2:

37、 25 m Pt tip,+ sensitivity lateral resolution (diffusion profiles) time dependency,+ lateral resolution high background current redox mediator required,12,扫描电化学显微镜瑞士万通学习报告,61,working distance depends on tip size,tip crash,Constant-Height vs. Constant-Distance Mode SECM When using a very small probe

38、(sub-m), or scanning a rough sample, the distance dependency of the current signal can cause difficulties. loss of nearfield interaction,13,扫描电化学显微镜瑞士万通学习报告,62,Constant-Height Mode SECM,itip,z-position,ii,Electrochemical activity and topography influence the tip signal (data interpretation difficult

39、).,14,扫描电化学显微镜瑞士万通学习报告,63,Constant-Distance Mode SECM,itip,z-position,i,Tip follows topography and the tip signal represents the electrochemical activity.,15,扫描电化学显微镜瑞士万通学习报告,64,magnitude / mV,Requires special vibratory SECM tips,Constant-Distance SECM Detection of shearforce interactions for curren

40、t independent distance control Piezo element,Agitator,Detector,8 6 4 2 0,10,200,250,350,400,300 frequency / kHz,solution sf regime,16,扫描电化学显微镜瑞士万通学习报告,65,MAG / mV,Constant-Distance SECM Approach Curve,0,1,2,3,6 4,16 14 12 10 8,interaction range,contact,bulk signal set point shearforce,z-position / m 17,扫描电化学显微镜瑞士万通学习报告,66,Constant-Distance SECM Set Point,