Ramabadran Uma, Ryan Gillian, Zhou Xuan, Farhat Susan, Manciu Felicia, Tong Yigang, Ayler Ryan, Garner Graham
Department of Physics, Kettering University, Flint, MI 48504, USA.
Department of Electrical and Computer Engineering, Kettering University, Flint, MI 48504, USA.
Materials (Basel). 2017 Nov 11;10(11):1295. doi: 10.3390/ma10111295.
The focus of this paper is the investigation of reduced graphene oxide (GO)/nickel foam (RGON) samples for use as supercapacitor electrodes. Nickel foam samples were soaked in a GO suspension and dried before being subjected to two different methods to remove oxygen. Atmospheric pressure annealed (APA) samples were treated with a varying number (10-18) of nitrogen plasma jet scans, where sample temperatures did not exceed 280 °C. Furnace annealed (FA) samples were processed in an atmosphere of hydrogen and argon, at temperatures ranging from 600 °C to 900 °C. Environmental Scanning Electron Microscope (ESEM) data indicated that the carbon to oxygen (C:O) ratio for APA samples was minimized at an intermediate number of plasma scans. Fourier Transform Infrared Spectroscopic (FTIR) and Raman spectroscopic data supported this finding. ESEM analysis from FA samples showed that with increasing temperatures of annealing, GO is transformed to reduced graphene oxide (RGO), with C:O ratios exceeding 35:1. X-ray Photoelectron Spectroscopy (XPS) and X-ray diffraction (XRD) data indicated the formation of RGO with an increasing annealing temperature until 800 °C, when oxygen reincorporation in the surface atomic layers becomes an issue. Supercapacitors, constructed using the FA samples, demonstrated performances that correlated with surface atomic layer optimization of the C:O ratio.
本文的重点是研究用作超级电容器电极的还原氧化石墨烯（GO）/泡沫镍（RGON）样品。将泡沫镍样品浸泡在GO悬浮液中，干燥后采用两种不同方法去除氧。常压退火（APA）样品用不同次数（10 - 18次）的氮等离子体射流扫描处理，样品温度不超过280℃。炉内退火（FA）样品在氢气和氩气气氛中，于600℃至900℃的温度范围内进行处理。环境扫描电子显微镜（ESEM）数据表明，APA样品的碳氧（C:O）比在中等次数的等离子体扫描时最小。傅里叶变换红外光谱（FTIR）和拉曼光谱数据支持了这一发现。FA样品的ESEM分析表明，随着退火温度升高，GO转变为还原氧化石墨烯（RGO），C:O比超过35:1。X射线光电子能谱（XPS）和X射线衍射（XRD）数据表明，直到800℃，随着退火温度升高形成RGO，此时表面原子层中氧的重新掺入成为一个问题。使用FA样品构建的超级电容器表现出与C:O比的表面原子层优化相关的性能。
