Carbon quantum dots/nickel oxide (CQDs/NiO) nanorods with high capacitance for supercapacitors

RSC Advances ◽  
2016 ◽  
Vol 6 (7) ◽  
pp. 5541-5546 ◽  
Author(s):  
J. Xu ◽  
Y. Xue ◽  
J. Cao ◽  
G. Wang ◽  
Y. Li ◽  
...  

Novel CQDs/NiO nanorods have been prepared via a facile complexation method followed by a thermal treatment process and used as electroactive materials for supercapacitors, which deliver a high specific capacitance of 1858 F g−1 at 1 A g−1.

2015 ◽  
Vol 44 (19) ◽  
pp. 9221-9229 ◽  
Author(s):  
K. Bhattacharya ◽  
P. Deb

Here, the novel Fe3O4-C hybrid nanocomposite demonstrates high specific capacitance (S.C.) than the pristine Fe3O4nanospheres due to the presence of the highly conducting carbon quantum dots.


2020 ◽  
Vol 20 (6) ◽  
pp. 3785-3794 ◽  
Author(s):  
Manohar D. Mehare ◽  
Abhay D. Deshmukh ◽  
S. J. Dhoble

A sucrose derived carbon quantum dots/polyaniline (S-CQD/PANI) nanocomposite was synthesized as electrode materials by electrodeposition method to achieve excellent electrocapacitive performance for supercapacitor application. The morphology reveals that CQD were distributed uniformly over the surface of PANI. The highest specific capacitance obtained to be 1512.4 Fg−1 at current density 1 Ag−1 for S-CQD/PANI-25 composite in three electrode system with 1 M H2SO4 aqueous electrolyte within the potential range of −0.2 to 0.8 V. In addition asymmetric supercapacitor device was fabricated reveals highest specific capacitance of 295 Fg−1 at 1 Ag−1 with excellent stability over 1000 cycle at 3 Ag−1. Remarkably, the device delivers energy density of 40.86 Whkg−1 at power density 2000 Wkg−1.


2016 ◽  
Vol 52 (58) ◽  
pp. 9141-9144 ◽  
Author(s):  
J. A. Carrasco ◽  
J. Romero ◽  
G. Abellán ◽  
J. Hernández-Saz ◽  
S. I. Molina ◽  
...  

Low temperature carbonization of Ni-MOF-74 yields carbon with high specific capacitance linked to the presence of very small micropores.


2020 ◽  
Vol 10 (16) ◽  
pp. 5462
Author(s):  
Jing Wang ◽  
Youyang Chen ◽  
Zhihao Hu ◽  
Ye Ge ◽  
Guotao Dong ◽  
...  

Based on various carbon nano materials, the ternary composite functionalized carbon nanotubes (FMWCNTs) @ carbon quantum dots (CQDs) @ polyaniline (PANI) was prepared by in-situ polymerization and hydrothermal method. The carbon-based material was made into an electrode sheet. The morphology and microscopic nanostructures were characterized by FTIR, field emission scanning electron microscopy and field emission transmission electron microscopy. Cyclic voltammetry and the galvanostatic charge discharge method was adapted to study the electrochemical properties of these active materials. Our results showed that the specific capacitance of FMWCNTs @ CQDs @ PANI was as high as 534 F/g, while it was 362 F/g, 319 F/g and 279 F/g for PANI @ FMWCNTs, PANI @ CQDs and polyaniline. This means that the specific capacitance of FMWCNTs @ CQDs @ PANI is increased by 47.5%, 67.4% and 91.4% comparing with the capacitance of PANI @ FMWCNTs, PANI @ CQDs and polyaniline, respectively. Moreover, the specific capacitance retention rate of the ternary active electrode after 1000 times of constant current charge and discharge cycle reached 86%, while it was 60% for PANI @ FMWCNTs, 72% for PANI @ CQDs and 65% for polyaniline.


Molecules ◽  
2021 ◽  
Vol 26 (16) ◽  
pp. 4891
Author(s):  
Xiuya Wang ◽  
Ke Wan ◽  
Pengbo Xie ◽  
Yuanyuan Miao ◽  
Zhenbo Liu

With increasing energy demand driving the need for eco-friendly and efficient energy storage technology, supercapacitors are becoming increasingly prevalent in wearable devices because of their portability and stability. The performance of these supercapacitors is highly dependent on the choice of electrode material. The high capacitance and mechanical properties needed for these materials can be achieved by combining graphene’s stable electrical properties with renewable cellulose’s excellent mechanical properties into porous aerogels. In this study, graphene-cellulose hydrogels were prepared by a one-step hydrothermal method, with porous, ultra-light, and mechanically strong graphene-cellulose aerogels then prepared by freeze-drying. These composite aerogels possess excellent mechanical strength and high specific capacitance, capable of bearing about 1095 times the pressure of their own weight. Electrochemical tests show the specific capacitance of these composite aerogels can reach 202 F/g at a scanning rate of 5 mA/cm2. In view of their high surface area and fast charge transport provided by their 3D porous structure, graphene-cellulose aerogels have great potential as sustainable supercapacitor electrodes.


2017 ◽  
Vol 41 (21) ◽  
pp. 13130-13139 ◽  
Author(s):  
S. Solomon Jones ◽  
Parikshit Sahatiya ◽  
Sushmee Badhulika

In this work, we demonstrate the high-yield synthesis of carbon quantum dots using a one-step eco-friendly, low-cost thermal treatment of a renewable biomass, i.e. natural chia seeds.


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