Fabrication of MnO2/carbon micro/nanostructures based on Carbon-MEMS technique on stainless steel substrate for supercapacitive microelectrodes

Fabrication of carbon micro/nanostructures by carbon microelectromechanical systems (carbon-MEMS) technique on conductive substrate stably is of great significance but difficulty, for the poor adhesive property and low - temperature resistance of the substrate. In this study, three-dimensional carbon micro/nanostructures are fabricated on stainless steel (SS) substrate for the first time by carbon-MEMS technique and oxygen plasma etching process without extra conductive layer fabrication process. The effects of oxygen plasma etching time and the height of photoresist array on the morphologies of carbon micro/nanostructures are investigated. The carbon micro/nanostructures were then electrodeposited with manganese dioxide (MnO2) thin film as microelectrodes for supercapacitors, and the electrochemical performances of the microelectrodes were demonstrated. At the current density of 0.05 mAcm(-2), the MnO2/carbon micro/nanostructures microelectrode deposited with 5min show a large specific capacitance of 453.47 F g(-1). It also shows excellent long-term cycling stability of-94% capacitance retention even after 6000 cycling tests. This study shows that the MnO2/carbon micro/nanostructures microelectrodes have great potential for supercapacitors as micro-energy storage devices, and the proposed approach of fabricating carbon hierarchical micro/nanostructures array on a conductive substrate is promising for large-scale micro/nanostructures manufacturing. (c) 2019 Elsevier Ltd. All rights reserved.

由于基底的粘附性差且耐低温性低，通过碳微机电系统（碳 - MEMS）技术在导电基底上稳定地制备碳微/纳米结构具有重要意义，但也存在困难。在本研究中，首次通过碳 - MEMS技术和氧等离子体蚀刻工艺，在不锈钢（SS）基底上制备了三维碳微/纳米结构，且无需额外的导电层制备工艺。研究了氧等离子体蚀刻时间和光刻胶阵列高度对碳微/纳米结构形貌的影响。然后将碳微/纳米结构作为超级电容器的微电极电沉积二氧化锰（MnO₂）薄膜，并对微电极的电化学性能进行了测试。在电流密度为0.05 mA/cm²时，沉积5分钟的MnO₂/碳微/纳米结构微电极显示出453.47 F/g的高比电容。即使经过6000次循环测试，它也显示出优异的长期循环稳定性，电容保持率为94%。本研究表明，MnO₂/碳微/纳米结构微电极作为微储能装置在超级电容器方面具有巨大潜力，并且所提出的在导电基底上制备碳分级微/纳米结构阵列的方法对于大规模微/纳米结构制造是有前景的。（c）2019爱思唯尔有限公司。保留所有权利。