Lei Cheng

Bio: Lei Cheng is an academic researcher from Xi'an Jiaotong University. The author has contributed to research in topics: Materials science & Electrochemical cell. The author has an hindex of 3, co-authored 6 publications receiving 15 citations.

Scanning Electrochemical Cell Microscopy Platform with Local Electrochemical Impedance Spectroscopy.

Abstract: Local electrochemical impedance spectroscopy (LEIS) has been a versatile technology for characterizing local complex electrochemical processes at heterogeneous surfaces. However, further application of this technology is restricted by its poor spatial resolution. In this work, high-spatial-resolution LEIS was realized using scanning electrochemical cell microscopy (SECCM-LEIS). The spatial resolution was proven to be ∼180 nm based on experimental and simulation results. The stability and reliability of this platform were further verified by long-term tests and Kramers-Kronig transformation. With this technology, larger electric double-layer capacitance (Cdl) and smaller interfacial resistance (Rt) were observed at the edges of N-doped reduced graphene oxide, as compared to those at the planar surface, which may be due to the high electrochemical activity at the edges. The established SECCM-LEIS provides a high-spatial approach for study of the interfacial electrochemical behavior of materials, which can contribute to the elucidation of the electrochemical reaction mechanism at material surfaces.

High Spatial Resolution Electrochemical Microscopic Observation of Enhanced Charging under Bias at Active Sites of N-rGO

Abstract: Recent breakthrough reveals that the activation free energy decreases with the amount of the oxidative charge stored at the catalyst, which gives an insight into the role of chemistry vs bias in el...

A fuzzy control for high-speed and low-overshoot hopping probe ion conductance microscopy.

Abstract: At present, hopping probe ion conductance microscopy (HPICM) is the most capable ion conductance microscopy for imaging complex surface topography. However, the HPICM controller usually does not begin to stop the pipette sample approach until the ion current reaches a threshold, which results in short deceleration distances. Furthermore, closed-loop piezo actuation usually increases the response time. These problems tend to increase the ion current overshoot and affect imaging speed and quality. A fuzzy control system was developed to solve these problems via ion current deviation and deviation rate. This lengthens the deceleration distance to enable a high-speed approach toward the sample and smooth deceleration. Open-loop control of the piezo actuator is also used to increase sensitivity. To compensate for the nonlinearity of the actuator, a multi-section fuzzy logic strategy was used to maintain performance in all sections. Glass and poly(dimethylsiloxane) samples were used to demonstrate greater imaging speed and stability of the fuzzy controller relative to those of conventional controllers.

Scanning Ion Conductance Microscopy.

Abstract: Scanning ion conductance microscopy (SICM) has emerged as a versatile tool for studies of interfaces in biology and materials science with notable utility in biophysical and electrochemical measurements. The heart of the SICM is a nanometer-scale electrolyte filled glass pipette that serves as a scanning probe. In the initial conception, manipulations of ion currents through the tip of the pipette and appropriate positioning hardware provided a route to recording micro- and nanoscopic mapping of the topography of surfaces. Subsequent advances in instrumentation, probe design, and methods significantly increased opportunities for SICM beyond recording topography. Hybridization of SICM with coincident characterization techniques such as optical microscopy and faradaic electrodes have brought SICM to the forefront as a tool for nanoscale chemical measurement for a wide range of applications. Modern approaches to SICM realize an important tool in analytical, bioanalytical, biophysical, and materials measurements, where significant opportunities remain for further exploration. In this review, we chronicle the development of SICM from the perspective of both the development of instrumentation and methods and the breadth of measurements performed.

The New Era of High-Throughput Nanoelectrochemistry

Abstract: ACCESS Metrics & More Article Recommendations ■ CONTENTS High-Throughput Nanopores 320 Nanopore Working Principle 320 Arrayed Nanopore Configurations 321 Machine-Learning Assisted Nanopore Readout 321 Integration Modalities for Nanopores 321 Nanopore-Confined Electrochemistry 322 High-Throughput Scanning Ion Conductance Microscopy 324 From Nanopore to Nanoprobe 324 High-Throughput SICM 324 High-Throughput Imaging 325 High-Throughput Single-Cell Manipulation and Measurements 326 SICM as an Electrochemical Probe 326 Applications in Material Sciences 327 Applications in Life Sciences 328 High-Throughput Scanning Electrochemical Cell Microscopy 329 Technical and Theoretical Developments 329 Electrochemical Measurements and Characterization 331 Popular Redox Reactions and Electrode Materials 331 Corrosion 332 Phase Formation 332 Two-Dimensional Materials 333 Photoelectrochemistry 335 Electrocatalysis: Single Particles and PseudoSingle-Crystal Screening of Structure−Activity 336 Battery Electrode Materials 339 Optical Microscopies in Electrochemistry 339 Overview of Operational Principles 339 Operational Principles 339 Methodologies for Quantitative Image Analysis 340 Converting Local Optical Information into an Electrochemically Relevant Signal 340 Computing and Automatized Image Analysis 340 Imaging Single Events 340 A Complement to Single Nanoobject Electrochemistry 340 Electron Transfer 341 Probing Concentration Profiles 341 Conversion 341 Growth and Dissolution 342 Catalysis and Motion 342 Competing Processes 343 Electrochemistry versus Physical Transformation 343 Competing Electrochemical Reactions 344 One versus Many 344 Seeing Collective Behaviors 344 How to Access Missing Pieces of Information 344 Hyphenation with Local Complementary Information 345 Other Electrochemical and Electronic HighThroughput Imaging Techniques 345 Conclusion 346 Author Information 347 Corresponding Authors 347 Authors 347 Author Contributions 347 Notes 347 Biographies 347 Acknowledgments 348 List of Abbreviations Used 348 References 349