scholarly journals Molecular origin of negative component of Helmholtz capacitance at electrified Pt(111)/water interface

2020 ◽  
Vol 6 (41) ◽  
pp. eabb1219
Author(s):  
Jia-Bo Le ◽  
Qi-Yuan Fan ◽  
Jie-Qiong Li ◽  
Jun Cheng
Keyword(s):  
Ab Initio Molecular Dynamics ◽  
Double Layers ◽  
Valuable Insight ◽  
Liquid Interfaces ◽  
Metal Electrodes ◽  
Physicochemical Processes ◽  
Colloid Science ◽  
Dynamics Simulations ◽  
Solid Liquid ◽  
Insight Into

Electrified solid/liquid interfaces are the key to many physicochemical processes in a myriad of areas including electrochemistry and colloid science. With tremendous efforts devoted to this topic, it is unexpected that molecular-level understanding of electric double layers is still lacking. Particularly, it is perplexing why compact Helmholtz layers often show bell-shaped differential capacitances on metal electrodes, as this would suggest a negative capacitance in some layer of interface water. Here, we report state-of-the-art ab initio molecular dynamics simulations of electrified Pt(111)/water interfaces, aiming at unraveling the structure and capacitive behavior of interface water. Our calculation reproduces the bell-shaped differential Helmholtz capacitance and shows that the interface water follows the Frumkin adsorption isotherm when varying the electrode potential, leading to a peculiar negative capacitive response. Our work provides valuable insight into the structure and capacitance of interface water, which can help understand important processes in electrocatalysis and energy storage in supercapacitors.

scholarly journals Shining light on the solid–liquid interface: in situ/operando monitoring of surface catalysis

2020 ◽  
Vol 10 (16) ◽  
pp. 5362-5385
Author(s):  
Leila Negahdar ◽  
Christopher M. A. Parlett ◽  
Mark A. Isaacs ◽  
Andrew M. Beale ◽  
Karen Wilson ◽  
...  
Keyword(s):  
Liquid Interface ◽  
Solid Catalyst ◽  
Chemical Transformations ◽  
Liquid Interfaces ◽  
Surface Catalysis ◽  
Catalytically Active ◽  
Solid Liquid Interface ◽  
Solid Liquid ◽  
Insight Into

Many industrially important chemical transformations occur at the interface between a solid catalyst and liquid reactants. In situ and operando spectroscopies offer unique insight into the reactivity of such catalytically active solid–liquid interfaces.

Heat Transfer Across Crystalline and Amorphous Silicon Surfaces in Contact With Water and the Effects of the Interfacial Liquid Structuring

2018 ◽  
Author(s):  
Luis E. Paniagua-Guerra ◽  
C. Ulises Gonzalez-Valle ◽  
Bladimir Ramos-Alvarado
Keyword(s):  
Heat Transfer ◽  
Amorphous Silicon ◽  
Linear Response Theory ◽  
Silicon Surfaces ◽  
Liquid Interfaces ◽  
Thermal Boundary Conductance ◽  
Wide Range ◽  
Out Of Plane ◽  
Dynamics Simulations ◽  
Solid Liquid

The understanding of nanoscale heat transfer across solid-liquid interfaces poses similar challenges as solid-solid interfaces; however, the higher mobility of liquid particles increases the complexity of this problem. It has been observed that liquid particles tend to form organized structures in the vicinity of solid surfaces; additionally, the formation of such structures has been reported to correlate with heat transfer across interfaces. Classical molecular dynamics simulations were used to investigate the behavior of liquid water in contact with crystalline and amorphous silicon. The in-plane and out-of-plane structure of interfacial water was characterized under different artificial wettability conditions, i.e., the silicon-water interaction potentials were calibrated to reproduce a wide range of wettability conditions. The change in the vibrational density of states was analyzed in order to quantify the mismatch between modes on both sides of the solid-liquid interfaces. Linear response theory was used to calculate the thermal boundary conductance at the different interfaces and a correlation was found between surface chemistry and heat transfer.

scholarly journals Cross-over in the dynamics of polymer confined between two liquids of different viscosity

2019 ◽  
Vol 9 (3) ◽  
pp. 20180074 ◽  
Author(s):  
Giuliana Giunta ◽  
Paola Carbone
Keyword(s):  
Dynamic Behaviour ◽  
High Viscosity ◽  
Polymer Dynamics ◽  
Liquid Interfaces ◽  
Immiscible Liquids ◽  
Molecular Weights ◽  
Dilute Polymer Solutions ◽  
Solvent Molecules ◽  
Dynamics Simulations ◽  
Solid Liquid

Using molecular dynamics simulations, we analysed the polymer dynamics of chains of different molecular weights entrapped at the interface between two immiscible liquids. We showed that on increasing the viscosity of one of the two liquids the dynamic behaviour of the chain changes from a Zimm-like dynamics typical of dilute polymer solutions to a Rouse-like dynamics where hydrodynamic interactions are screened. We observed that when the polymer is in contact with a high viscosity liquid, the number of solvent molecules close to the polymer beads is reduced and ascribed the screening effect to this reduced number of polymer–solvent contacts. For the longest chain simulated, we calculated the distribution of loop length and compared the results with the theoretical distribution developed for solid/liquid interfaces. We showed that the polymer tends to form loops (although flat against the interface) and that the theory works reasonably well also for liquid/liquid interfaces.

scholarly journals Nonequilibrium molecular dynamics simulations of nanoconfined fluids at solid-liquid interfaces

2017 ◽  
Vol 146 (24) ◽  
pp. 244507 ◽  
Author(s):  
M. Morciano ◽  
M. Fasano ◽  
A. Nold ◽  
C. Braga ◽  
P. Yatsyshin ◽  
...  
Keyword(s):  
Molecular Dynamics ◽  
Molecular Dynamics Simulations ◽  
Nonequilibrium Molecular Dynamics ◽  
Liquid Interfaces ◽  
Dynamics Simulations ◽  
Solid Liquid

Study of Solid/liquid Interfaces in Organic Field-effect Transistors with Ionic Liquids

2009 ◽  
Vol 1154 ◽  
Author(s):  
Shimpei Ono ◽  
Kazumoto Miwa ◽  
Shiro Seki ◽  
Jun Takeya
Keyword(s):  
Ionic Liquid ◽  
Field Effect ◽  
Carrier Mobility ◽  
Gate Dielectric ◽  
Field Effect Transistors ◽  
High Mobility ◽  
Double Layers ◽  
Liquid Interfaces ◽  
Organic Thin Film ◽  
Solid Liquid

AbstractWe report high-mobility rubrene single-crystal field-effect transistors with ionic-liquid electrolytes used for gate dielectric layers. As the result of fast ionic diffusion to form electric double layers, their capacitances remain more than 1.0 μF/cm2 even at 0.1 MHz. With high carrier mobility of 9.5 cm2/Vs in the rubrene crystal, pronounced current amplification is achieved at the gate voltage of only 0.2 V, which is two orders of magnitude smaller than that necessary for organic thin-film transistors with dielectric gate insulators. The results demonstrate that the ionic-liquid/organic semiconductor interfaces are suited to realize low-power and fast-switching field-effect transistors without sacrificing carrier mobility in forming the solid/liquid interfaces.

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