Modelling pH and potential in dynamic structures of the water/Pt(111) interface on the atomic scale

2017 ◽  
Vol 19 (34) ◽  
pp. 23505-23514 ◽  
Author(s):  
Martin Hangaard Hansen ◽  
Anders Nilsson ◽  
Jan Rossmeisl
Keyword(s):  
Electrode Potential ◽  
Atomic Scale ◽  
Potential Scale ◽  
Work Functions ◽  
The Absolute ◽  
Absolute Potential ◽  
Dynamic Structures ◽  
Grand Canonical

Modelling liquid structures averages of water in the interface with Pt(111) as grand canonical averages, that are functions of pH and electrode potential, using work functions as the absolute potential scale.

scholarly journals Mapping the Electronic Structure of Polypyrrole with Image-Based Electrochemical Scanning Tunnelling Spectroscopy

2020 ◽  
Author(s):  
Roger Goncalves ◽  
Robert S. Paiva ◽  
Andres M R Ramirez ◽  
Jonathan A Mwanda ◽  
Ernesto C. Pereira ◽  
...  
Keyword(s):  
Electronic Structure ◽  
Electrochemical Impedance ◽  
Wide Range ◽  
Scanning Tunnelling ◽  
Potential Scale ◽  
Electrochemically Deposited ◽  
Interfacial Capacitance ◽  
The Absolute ◽  
Absolute Potential ◽  
Scanning Tunnelling Spectroscopy

Conducting polymers are versatile semiconductors whose applications cover a wide range of devices. Their versatility is due, in addition to other factors, to properties that can be easily modulated according to the intended application. It is therefore important to study and map the electronic structure of these materials to allow for a better correlation between structure and properties. Electrochemical scanning tunnelling spectroscopy (EC-STS) can be a powerful tool to characterize the electronic structure of the semiconductor electrolyte interface. In this work we have used image-based EC-STS (IB-EC-STS) to describe quantitatively the band structure of an electrochemically deposited polypyrrole (PPy) film. IB-EC-STS located the band edge of the polymer’s valence band (VB) at 0.95 V vs. RHE (-5.33 eV in the absolute potential scale) and the intragap polaron states formed when the polymer is oxidised (doped) at 0.46 V vs. RHE (-4.84 eV in the absolute potential scale). The IB-EC-STS data were cross checked with electrochemical impedance spectroscopy (EIS) and Mott-Schottky analysis of the interfacial capacitance. The DOS spectrum obtained from EIS data is consistent with the STS-deduced location of the VB and the polarons.

scholarly journals Mapping the Electronic Structure of Polypyrrole with Image-Based Electrochemical Scanning Tunnelling Spectroscopy

2020 ◽  
Author(s):  
Roger Goncalves ◽  
Robert S. Paiva ◽  
Andres M R Ramirez ◽  
Jonathan A Mwanda ◽  
Ernesto C. Pereira ◽  
...  
Keyword(s):  
Electronic Structure ◽  
Electrochemical Impedance ◽  
Wide Range ◽  
Scanning Tunnelling ◽  
Potential Scale ◽  
Electrochemically Deposited ◽  
Interfacial Capacitance ◽  
The Absolute ◽  
Absolute Potential ◽  
Scanning Tunnelling Spectroscopy

Conducting polymers are versatile semiconductors whose applications cover a wide range of devices. Their versatility is due, in addition to other factors, to properties that can be easily modulated according to the intended application. It is therefore important to study and map the electronic structure of these materials to allow for a better correlation between structure and properties. Electrochemical scanning tunnelling spectroscopy (EC-STS) can be a powerful tool to characterize the electronic structure of the semiconductor electrolyte interface. In this work we have used image-based EC-STS (IB-EC-STS) to describe quantitatively the band structure of an electrochemically deposited polypyrrole (PPy) film. IB-EC-STS located the band edge of the polymer’s valence band (VB) at 0.95 V vs. RHE (-5.33 eV in the absolute potential scale) and the intragap polaron states formed when the polymer is oxidised (doped) at 0.46 V vs. RHE (-4.84 eV in the absolute potential scale). The IB-EC-STS data were cross checked with electrochemical impedance spectroscopy (EIS) and Mott-Schottky analysis of the interfacial capacitance. The DOS spectrum obtained from EIS data is consistent with the STS-deduced location of the VB and the polarons.

scholarly journals Mapping the Electronic Structure of Polypyrrole with Image-Based Electrochemical Scanning Tunnelling Spectroscopy

2020 ◽  
Author(s):  
Roger Goncalves ◽  
Robert S. Paiva ◽  
Andres M R Ramirez ◽  
Jonathan A Mwanda ◽  
Ernesto C. Pereira ◽  
...  
Keyword(s):  
Electronic Structure ◽  
Electrochemical Impedance ◽  
Wide Range ◽  
Scanning Tunnelling ◽  
Potential Scale ◽  
Electrochemically Deposited ◽  
Interfacial Capacitance ◽  
The Absolute ◽  
Absolute Potential ◽  
Scanning Tunnelling Spectroscopy

Conducting polymers are versatile semiconductors whose applications cover a wide range of devices. Their versatility is due, in addition to other factors, to properties that can be easily modulated according to the intended application. It is therefore important to study and map the electronic structure of these materials to allow for a better correlation between structure and properties. Electrochemical scanning tunnelling spectroscopy (EC-STS) can be a powerful tool to characterize the electronic structure of the semiconductor electrolyte interface. In this work we have used image-based EC-STS (IB-EC-STS) to describe quantitatively the band structure of an electrochemically deposited polypyrrole (PPy) film. IB-EC-STS located the band edge of the polymer’s valence band (VB) at 0.95 V vs. RHE (-5.33 eV in the absolute potential scale) and the intragap polaron states formed when the polymer is oxidised (doped) at 0.46 V vs. RHE (-4.84 eV in the absolute potential scale). The IB-EC-STS data were cross checked with electrochemical impedance spectroscopy (EIS) and Mott-Schottky analysis of the interfacial capacitance. The DOS spectrum obtained from EIS data is consistent with the STS-deduced location of the VB and the polarons.

Enhancing hydrogen evolution activity by doping and tuning the curvature of manganese-embedded carbon nanotubes

2019 ◽  
Vol 9 (19) ◽  
pp. 5301-5314 ◽  
Author(s):  
Haijun Liu ◽  
Lianming Zhao ◽  
Yonghui Liu ◽  
Jing Xu ◽  
Houyu Zhu ◽  
...  
Keyword(s):  
Carbon Nanotubes ◽  
Hydrogen Evolution ◽  
Electrode Potential ◽  
Band Center ◽  
The Absolute

Doping heteroatoms (Mn and N) and tuning the curvature of carbon nanotubes could efficiently elevate the C p-band center, lower the absolute electrode potential, and thus enhance the HER performance.

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