Preparation of reduced graphene oxide by infrared irradiation induced photothermal reduction

We present a green and scalable route toward the formation of reduced graphene oxide (r-GO) by photothermal reduction induced by infrared (IR) irradiation, utilizing a bathroom IR lamp as the source of IR light. Thermogravimetric analysis, Raman, Fourier transform infrared spectroscopy and X-ray photoelectron spectroscopy confirm the reduction of r-GO by IR light. Ultraviolet-visible-infrared spectra indicate that adsorption of IR light by original GO films is less than that of UV and visible light; but when GO is exposed to IR light, its adsorption of IR light increases very rapidly with time. The influence of the power density of the IR light on the structure and properties of r-GO was investigated. At high IR power density, the reduction reaction was so fierce that r-GO became highly porous due to the rapid degassing and exfoliation of GO sheets. The r-GO powder revealed good performance as the anode material for lithium ion batteries. At relatively low IR power density, the reduction process was found to be mild but relatively slow. Crack-free and uniform conductive r-GO thin films with a volume conductivity of 1670 S m(-1) were then prepared by two-step IR irradiation, i.e. first at low IR power density and then at high IR power density. Moreover, the r-GO films were also observed to exhibit obvious and reversible IR light-sensing behavior.

我们提出了一种绿色且可扩展的方法，通过红外（IR）照射诱导的光热还原形成还原氧化石墨烯（r - GO），利用浴室用的红外灯作为红外光源。热重分析、拉曼光谱、傅里叶变换红外光谱和X射线光电子能谱证实了红外光对r - GO的还原作用。紫外 - 可见 - 红外光谱表明，原始氧化石墨烯薄膜对红外光的吸收少于对紫外光和可见光的吸收；但是当氧化石墨烯暴露于红外光下时，其对红外光的吸收随时间迅速增加。研究了红外光功率密度对r - GO结构和性能的影响。在高红外功率密度下，还原反应非常剧烈，由于氧化石墨烯片层的快速脱气和剥离，r - GO变得高度多孔。r - GO粉末作为锂离子电池的阳极材料表现出良好性能。在相对较低的红外功率密度下，发现还原过程温和但相对缓慢。通过两步红外照射，即先在低红外功率密度下，然后在高红外功率密度下，制备出了无裂纹且均匀的导电r - GO薄膜，其体积电导率为1670 S/m（-1）。此外，还观察到r - GO薄膜表现出明显且可逆的红外光传感行为。