Simplified Synthesis of 3D Flexible Reduced Graphene Oxide-Wrapped NiCo2O4 Nanowires for High-Performance Supercapacitor

2018 ◽  
Vol 10 (3) ◽  
pp. 358-364 ◽  
Author(s):  
Chao Pan ◽  
Hongyu Sun ◽  
Jingyi Gao ◽  
Yucai Hu ◽  
Jing Wang
Keyword(s):  
Graphene Oxide ◽  
Reduced Graphene Oxide ◽  
Current Density ◽  
Photoelectron Spectroscopy ◽  
High Performance ◽  
High Current Density ◽  
Three Dimensional ◽  
Simple Method ◽  
X Ray ◽  
Reduced Graphene

We introduced a simple method to construct novel three-dimensional (3D) flexible hierarchical nanocomposites by combining (1D) NiCo2O4 nanowires with 2D reduced graphene oxide (rGO) sheets. The hierarchical nanocomposite structure of rGO-wrapped NiCo2O4 (rGO-NiCo2O4) was confirmed by X-ray diffraction (XRD), Raman spectra, scanning electron microscopy (SEM), transmission electron microscope (TEM), and X-ray photoelectron spectroscopy (XPS). The results indicated that NiCo2O4 nanowires were successfully wrapped in rGO and the morphology of the rGO-NiCo2O4 showed a three-dimensional porous structure with NiCo2O4 being homogeneously distributed in the rGO. Given their apparent advantages, these two different nanostructures were evaluated as electrodes for high-performance supercapacitors. These electrodes exhibited a high capacitance of 1824.8 F·g–1 at a current density of 0.5 A·g–1, and an excellent cycling performance extending to 5000 cycles at a high current density of 4 A·g–1. Our results clearly demonstrate that rGO sheets on NiCo2O4 nanowires can substantially improve the capacitive performance of materials and ultimately increase the cycling stability of supercapacitors. The hierarchical binary nanocomposites show excellent electrochemical properties for energy storage applications, evidencing their potential application as supercapacitors.

Porous CuCo2O4 nanocubes wrapped by reduced graphene oxide as high-performance lithium-ion battery anodes

Nanoscale ◽  
2014 ◽  
Vol 6 (12) ◽  
pp. 6551-6556 ◽  
Author(s):  
Wenpei Kang ◽  
Yongbing Tang ◽  
Wenyue Li ◽  
Zhangpeng Li ◽  
Xia Yang ◽  
...  
Keyword(s):  
Graphene Oxide ◽  
Lithium Ion Battery ◽  
Reduced Graphene Oxide ◽  
Current Density ◽  
High Performance ◽  
High Current Density ◽  
Lithium Ion ◽  
High Current ◽  
Reduced Graphene ◽  
Graphene Oxide Sheets

Porous CuCo2O4 nanocubes well wrapped by reduced graphene oxide sheets were facilely prepared and they showed impressive performance at high current density as the anode material of a lithium ion battery.

High-performance reduced graphene oxide – red phosphorous composites anodes for lithium batteries and soft X-ray near-edge structure studies

2017 ◽  
Vol 95 (11) ◽  
pp. 1178-1182
Author(s):  
Dongniu Wang ◽  
Lucia Zuin ◽  
David Muir
Keyword(s):  
Electronic Structure ◽  
Graphene Oxide ◽  
Reduced Graphene Oxide ◽  
High Performance ◽  
Solid Electrolyte Interphase ◽  
Three Dimensional ◽  
Lithium Storage ◽  
Edge Structure ◽  
X Ray ◽  
Reduced Graphene

A solution method was developed to synthesize reduced graphene oxide (RGO) – red phosphorous (RP) composites. The uniform distribution of RP particles into three-dimensional conductive RGO network was obtained. Due to both improved electronic structure and mechanical properties, the hybrids delivered a high lithium storage capacity with superior rate performance. For the first time, the electronic structure, as revealed by phosphorous (P) L-edge and lithium (Li) K-edge X-ray absorption near-edge structure (XANES), provides spectroscopic evidence to identify the lithiated products and solid electrolyte interphase. Charge distribution in between RP and RGO was also found by XANES, facilitating the anchoring of active RP into RGO surface.

Reduced Graphene Oxide Supported Molybdenum Oxide Hybrid Nanocomposites: High Performance Electrode Material for Supercapacitor and Photocatalytic Applications

2020 ◽  
Vol 20 (7) ◽  
pp. 4035-4046
Author(s):  
Rengasamy Dhanabal ◽  
Dhanasekaran Naveena ◽  
Sivan Velmathi ◽  
Arumugam Chandra Bose
Keyword(s):  
Electron Microscopy ◽  
Graphene Oxide ◽  
Reduced Graphene Oxide ◽  
Photoelectron Spectroscopy ◽  
Diffuse Reflectance Spectroscopy ◽  
Hybrid Nanocomposites ◽  
X Ray ◽  
Supercapacitor Application ◽  
Quenching Effect ◽  
Reduced Graphene

Using a simple solution based synthesis route, hexagonal MoO3 (h-MoO3) nanorods on reduced graphene oxide (RGO) sheets were prepared. The structure and morphology of resulting RGO-MoO3 nanocomposite were characterized using X-ray diffraction (XRD), Raman spectroscopy, Fourier transform infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS), atomic force microscopy (AFM), transmission electron microscopy (TEM) and field emission scanning electron microscopy (FESEM). The optical property was studied using UV-Visible diffuse reflectance spectroscopy (UV-Vis DRS) and photoluminescence spectroscopy (PL). The RGO-MoO3 nanocomposites were used as an electrode for supercapacitor application and photocatalyst for photodegradation of methylene blue (MB) and rhodamine B (RhB) under visible light irradiation. We demonstrated that the RGO-MoO3 electrode is capable of delivering high specific capacitance of 134 F/g at current density of 1 A/g with outstanding cyclic stability for 2000 cycles. The RGOMoO3 photocatalyst degrades 95% of MB dye within 90 min, and a considerable recyclability up to 4 cycles was observed. The quenching effect of scavengers test confirms holes are main reactive species in the photocatalytic degradation of MB. Further, the charge transfer process between RGO and MoO3 was schematically demonstrated.

scholarly journals Effects of Different TiO2 Particle Sizes on the Microstructure and Optical Limiting Properties of TiO2/Reduced Graphene Oxide Nanocomposites

Nanomaterials ◽  
2019 ◽  
Vol 9 (5) ◽  
pp. 730 ◽  
Author(s):  
Yuyu Ren ◽  
Lili Zhao ◽  
Yang Zou ◽  
Lixin Song ◽  
Ningning Dong ◽  
...  
Keyword(s):  
Graphene Oxide ◽  
Reduced Graphene Oxide ◽  
Photoelectron Spectroscopy ◽  
Optical Limiting ◽  
Tio2 Particle ◽  
Tetrabutyl Titanate ◽  
Particle Sizes ◽  
X Ray ◽  
Reduced Graphene ◽  
Source Materials

TiO2/reduced graphene oxide (rGO) nanocomposites with two different TiO2 particle sizes were synthesized by a facile hydrothermal method using two different source materials of Ti: tetrabutyl titanate (TBT) and commercial TiO2 powder (P25). For respective series with the same source materials, we investigated additions that optimized the nonlinear optical properties (NLO) and optical limiting (OL) performances, and we explored the relationships between structural diversity and performance. Several characterization techniques, including X-ray powder diffraction (XRD), X-ray photoelectron spectroscopy (XPS), transmission electron microscopy (TEM), Fourier-transform infrared spectroscopy (FTIR), Raman spectroscopy, and diffuse reflectance ultraviolet-visible spectroscopy (UV-Vis) were conducted to confirm the microstructures and chemical states of as-prepared materials. This indicated the existence of the Ti–O–C bond between rGO sheets and TiO2 particles and the reduction from precursor graphene oxide (GO) to rGO. The results of UV-Vis spectra revealed that the TiO2/rGO nanocomposites showed smaller band gaps than bare TiO2. A nanosecond open-aperture Z-scan technique at 1064 nm was applied to investigate NLO and OL properties. TiO2/rGO nanocomposites exhibited enhanced NLO and OL performances, arising from synergistic effects, compared to individual components. The TBT series samples performed better than the P25 series, presumably relevant to dimensional effects.

Sign in / Sign up

Export Citation Format

Share Document