scholarly journals Achieving Selective and Efficient Electrocatalytic Activity for CO2 Reduction on N-Doped Graphene

2021 ◽  
Vol 9 ◽  
Author(s):  
Xiaoxu Sun

The CO2 electrochemical reduction reaction (CO2RR) has been a promising conversion method for CO2 utilization. Currently, the lack of electrocatalysts with favorable stability and high efficiency hindered the development of CO2RR. Nitrogen-doped graphene nanocarbons have great promise in replacing metal catalysts for catalyzing CO2RR. By using the density functional theory (DFT) method, the catalytic mechanism and activity of CO2RR on 11 types of nitrogen-doped graphene have been explored. The free energy analysis reveals that the zigzag pyridinic N- and zigzag graphitic N-doped graphene possess outstanding catalytic activity and selectivity for HCOOH production with an energy barrier of 0.38 and 0.39 eV, respectively. CO is a competitive product since its free energy lies only about 0.20 eV above HCOOH. The minor product is CH3OH and CH4 for the zigzag pyridinic N-doped graphene and HCHO for zigzag graphitic N-doped graphene, respectively. However, for Z-pyN, CO2RR is passivated by too strong HER. Meanwhile, by modifying the pH value of the electrolyte, Z-GN could be selected as a promising nonmetal electrocatalyst for CO2RR in generating HCOOH.

Author(s):  
Eduardo Rangel ◽  
José Alfredo Pescador Pescador Rojas ◽  
Victor A. Cardozo-Mata ◽  
Arturo Hernández-Hernández ◽  
Emmanuel Vallejo ◽  
...  

The interaction between nitrogen-doped graphene defects (N3V1, N4V2 pyridinic, N3V1, N3V3 pyrrolic) and benzene have been investigated by applying density functional theory (DFT), together with the vdW–DF correction. We discovered...


Author(s):  
Anderson Soares da Costa Azevêdo ◽  
Aldilene Saraiva-Souza ◽  
Vincent Meunier ◽  
Eduardo Costa Girão

Theoretical analysis based on density functional theory is used to describe the microscopic origins of emerging electronic and magnetic properties in quasi-1D nitrogen-doped graphene nanoribbon structures with chevron-like (or wiggly-edged)...


Catalysts ◽  
2018 ◽  
Vol 8 (10) ◽  
pp. 438 ◽  
Author(s):  
Fei Li ◽  
Ming Li ◽  
Yi Luo ◽  
Ming Li ◽  
Xinyu Li ◽  
...  

In this study, nitrogen-doped graphene quantum dots (N-GQDs) and a TiO2 nanocomposite were synthesized using a simple hydrothermal route. Ammonia water was used as a nitrogen source to prepare the N-GQDs. When optically characterized by UV-vis, N-GQDs reveal stronger absorption peaks in the range of ultraviolet (UV) light than graphene quantum dots (GQDs). In comparison with GQDs/TiO2 and pure TiO2, the N-GQDs/TiO2 have significantly improved photocatalytic performance. In particular, it was found that, when the added amount of ammonia water was 50 mL, the content of pyridinic N and graphitic N were as high as 22.47% and 31.44%, respectively. Most important, the photocatalytic activity of N-GQDs/TiO2-50 was about 95% after 12 min. The results illustrated that pyridinic N and graphitic N play a significant role in photocatalytic performance.


2017 ◽  
Vol 8 (1) ◽  
Author(s):  
Jianwei Su ◽  
Yang Yang ◽  
Guoliang Xia ◽  
Jitang Chen ◽  
Peng Jiang ◽  
...  

Abstract The scalable production of hydrogen could conveniently be realized by alkaline water electrolysis. Currently, the major challenge confronting hydrogen evolution reaction (HER) is lacking inexpensive alternatives to platinum-based electrocatalysts. Here we report a high-efficient and stable electrocatalyst composed of ruthenium and cobalt bimetallic nanoalloy encapsulated in nitrogen-doped graphene layers. The catalysts display remarkable performance with low overpotentials of only 28 and 218 mV at 10 and 100 mA cm−2, respectively, and excellent stability of 10,000 cycles. Ruthenium is the cheapest platinum-group metal and its amount in the catalyst is only 3.58 wt.%, showing the catalyst high activity at a very competitive price. Density functional theory calculations reveal that the introduction of ruthenium atoms into cobalt core can improve the efficiency of electron transfer from alloy core to graphene shell, beneficial for enhancing carbon–hydrogen bond, thereby lowing ΔGH* of HER.


RSC Advances ◽  
2019 ◽  
Vol 9 (11) ◽  
pp. 6035-6041 ◽  
Author(s):  
Shih-Hsuan Tai ◽  
Bor Kae Chang

The oxygen reduction reaction (ORR) reactivity of various nitrogen-doped graphene configurations are probed in detail using density functional theory (DFT) calculations.


2018 ◽  
Vol 20 (3) ◽  
pp. 2057-2065 ◽  
Author(s):  
J. Vijaya Sundar ◽  
M. Kamaraj ◽  
V. Subramanian

An attempt has been made to investigate the possibility of utilizing nitrogen doped graphene for the aerobic oxidation of thiols to disulfides using density functional theory.


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