Mahmood Faisal, Zhang Chi, Xie Yunchao, Stalla David, Lin Jian, Wan Caixia
Department of Biomedical, Biological, and Chemical Engineering, University of Missouri Columbia 65211 USA
Department of Energy Systems Engineering, University of Agriculture Faisalabad Faisalabad 38000 Pakistan.
RSC Adv. 2019 Jul 23;9(39):22713-22720. doi: 10.1039/c9ra04073k. eCollection 2019 Jul 17.
Cost-effective valorization of lignin into carbon-based electrode materials remains a challenge. Here we reported a facile and ultrafast laser writing technique to convert lignin into porous graphene as active electrode material for solid-state supercapacitors (SCs). During laser writing, alkaline lignin experienced graphitization. By controlling laser parameters such as power the porous structure and graphitization degree can be well modulated. Graphene obtained at 80% of laser power setting (LIG-80) had higher graphene quality and more porous structure than that obtained at the lower power levels (, 50%, 70%). TEM images revealed that LIG-80 had few-layer graphene structure with fringe-like patterns. LIG-80 proved to be an active electrode material for SCs with a specific capacitance as high as 25.44 mF cm in a HSO/PVA gel electrolyte, which is comparable or even superior to SCs based on pristine LIG obtained from other carbon precursors. Taken together, our proposed technical route for lignin-based LIG and subsequent application in SCs would not only open a new avenue to lignin valorization, but also produce porous graphene from a renewable carbon precursor for energy storage applications.
将木质素经济高效地转化为碳基电极材料仍然是一项挑战。在此，我们报道了一种简便且超快的激光写入技术，可将木质素转化为多孔石墨烯，作为固态超级电容器（SCs）的活性电极材料。在激光写入过程中，碱性木质素发生了石墨化。通过控制激光参数，如功率，可以很好地调节多孔结构和石墨化程度。在80%激光功率设置下获得的石墨烯（LIG-80）比在较低功率水平（50%、70%）下获得的石墨烯具有更高的质量和更多孔的结构。透射电子显微镜图像显示，LIG-80具有带有条纹状图案的少层石墨烯结构。在HSO/PVA凝胶电解质中，LIG-80被证明是一种用于SCs的活性电极材料，其比电容高达25.44 mF cm，与基于从其他碳前驱体制备的原始LIG的SCs相当甚至更优。综上所述，我们提出的基于木质素的LIG技术路线及其在SCs中的后续应用，不仅将为木质素的增值开辟一条新途径，还将从可再生碳前驱体中制备多孔石墨烯用于储能应用。
