scholarly journals Conductivity mechanism in ionic 2D carbon nitrides: from hydrated ion motion to enhanced photocatalysis

2021 ◽  
pp. 2107061
Author(s):  
Julia Kröger ◽  
Filip Podjaski ◽  
Gökcen Savasci ◽  
Igor Moudrakovski ◽  
Alberto Jimenez‐Solano ◽  
...  
Keyword(s):  
Ion Motion ◽  
Conductivity Mechanism ◽  
Carbon Nitrides ◽  
Hydrated Ion

scholarly journals Conductivity mechanism in ionic 2D carbon nitrides: from hydrated ion motion to enhanced photocatalysis

2021 ◽  
Author(s):  
Julia Kröger ◽  
Filip Podjaski ◽  
Gökçen Savaşçı ◽  
Igor Moudrakovski ◽  
Alberto Jimenez-Solano ◽  
...  
Keyword(s):  
Photocatalytic Activity ◽  
Ionic Conductivity ◽  
Charge Carrier ◽  
Pore Channel ◽  
Ion Motion ◽  
Carrier Lifetimes ◽  
Carbon Nitrides ◽  
Efficient Charge ◽  
Mobile Ions ◽  
Hydrated Ion

Carbon nitrides are among the most studied materials for photocatalysis, however, limitations arise from inefficient charge separation and transport within the material. Here, this aspect is addressed in the 2D carbon nitride poly(heptazine imide) (PHI) by investigating the influence of various counterions, such as M = Li+, Na+, K+, Cs+, Ba2+, NH4+ and tetramethyl ammonium, on the material’s conductivity and photocatalytic activity. These ions in the PHI pores affect the stacking of the 2D layers, which further influences the predominantly ionic conductivity in M-PHI. Na-containing PHI outperforms the other M-PHI in various relative humidity (RH) environments (0-42 %RH) in terms of conductivity, likely due to pore channel geometry and size of the (hydrated) ion. With increasing RH, the ionic conductivity increases by 4-5 orders of magnitude (for Na-PHI up to 10-5 S cm-1 at 42 %RH). At the same time, the highest photocatalytic hydrogen evolution rate is observed for Na-PHI, which is mirrored by increased photo-generated charge carrier lifetimes, pointing to efficient charge carrier stabilization by mobile ions. These results indicate that ionic conductivity is an important parameter that can influence the photocatalytic activity. Besides, RH-dependent ionic conductivity is of high interest for separators, membranes, or sensors.

Dynamics of Ion Locking in Doubly Polymerized Ionic Liquids

2020 ◽  
Author(s):  
Swati Arora ◽  
Julisa Rozon ◽  
Jennifer Laaser
Keyword(s):  
Dielectric Constant ◽  
Ionic Liquid ◽  
Ionic Liquids ◽  
Ion Pairs ◽  
Polymer Chains ◽  
Ion Motion ◽  
Charged Species ◽  
Broadband Dielectric Spectroscopy ◽  
Covalently Linked ◽  
Insight Into

<div>In this work, we investigate the dynamics of ion motion in “doubly-polymerized” ionic liquids (DPILs) in which both charged species of an ionic liquid are covalently linked to the same polymer chains. Broadband dielectric spectroscopy is used to characterize these materials over a broad frequency and temperature range, and their behavior is compared to that of conventional “singly-polymerized” ionic liquids (SPILs) in which only one of the charged species is attached to the polymer chains. Polymerization of the DPIL decreases the bulk ionic conductivity by four orders of magnitude relative to both SPILs. The timescales for local ionic rearrangement are similarly found to be approximately four orders of magnitude slower in the DPILs than in the SPILs, and the DPILs also have a lower static dielectric constant. These results suggest that copolymerization of the ionic monomers affects ion motion on both the bulk and the local scales, with ion pairs serving to form strong physical crosslinks between the polymer chains. This study provides quantitative insight into the energetics and timescales of ion motion that drive the phenomenon of “ion locking” currently under investigation for new classes of organic electronics.</div>

Photochemistry of carbon nitrides and heptazine derivatives

2021 ◽  
Author(s):  
Doyk Hwang ◽  
Cody W. Schlenker
Keyword(s):  
Carbon Nitride ◽  
Monomer Unit ◽  
Carbon Nitrides

This article highlights the photochemistry of heptazine derivatives, a structural monomer unit of carbon nitride photocatalysts.

Numerical analysis of trajectories in a Cassinian ion trap of second order with trap door ion inlet

2021 ◽  
Vol 27 (1) ◽  
pp. 3-12
Author(s):  
Bjoern Raupers ◽  
Hana Medhat ◽  
Juergen Grotemeyer ◽  
Frank Gunzer
Keyword(s):  
Ion Trap ◽  
Ion Traps ◽  
Second Order ◽  
Resolving Power ◽  
Periodic Pattern ◽  
Ion Motion ◽  
Trap Door ◽  
Mass Resolving Power ◽  
Long Time ◽  
The Fourier Transform

Ion traps like the Orbitrap are well known mass analyzers with very high resolving power. This resolving power is achieved with help of ions orbiting around an inner electrode for long time, in general up to a few seconds, since the mass signal is obtained by calculating the Fourier Transform of the induced signal caused by the ion motion. A similar principle is applied in the Cassinian Ion Trap of second order, where the ions move in a periodic pattern in-between two inner electrodes. The Cassinian ion trap has the potential to offer mass resolving power comparable to the Orbitrap with advantages regarding the experimental implementation. In this paper we have investigated the details of the ion motion analyzing experimental data and the results of different numerical methods, with focus on increasing the resolving power by increasing the oscillation frequency for ions in a high field ion trap. In this context the influence of the trap door, a tunnel through which the ions are injected into the trap, on the ion velocity becomes especially important.

scholarly journals Understanding spontaneous dissolution of crystalline layered carbon nitride for tuneable photoluminescent solutions and glasses

2021 ◽  
Author(s):  
Adam J. Clancy ◽  
Theo M. Suter ◽  
Alaric Taylor ◽  
Sayantan Bhattacharya ◽  
Thomas S. Miller ◽  
...  
Keyword(s):  
Carbon Nitride ◽  
2D Materials ◽  
Carbon Nitrides

The spontaneous dissolution of 2D carbon nitrides with polytriazine imide (PTI) diverges dramatically from the inherent insolubility of other 2D materials such as graphene. The dissolution may be controlled to give tuneable photoluminescence.

scholarly journals Carbamate intermediates over mesoporous carbon nitrides in CO2 mediated oxidation reaction

2021 ◽  
Vol 6 ◽  
pp. 100102
Author(s):  
Mohd Bismillah Ansari ◽  
Ram Sambhar Shukla ◽  
Yong-Hwan Mo ◽  
Sang-Eon Park
Keyword(s):  
Mesoporous Carbon ◽  
Oxidation Reaction ◽  
Carbon Nitrides ◽  
Mediated Oxidation

scholarly journals Functionalized Graphitic Carbon Nitrides for Environmental and Sensing Applications

2021 ◽  
pp. 2000073
Author(s):  
Tuçe Fidan ◽  
Milad Torabfam ◽  
Qandeel Saleem ◽  
Chao Wang ◽  
Hasan Kurt ◽  
...  
Keyword(s):  
Graphitic Carbon ◽  
Sensing Applications ◽  
Carbon Nitrides
Sign in / Sign up

Export Citation Format

Share Document