Guo Shaokui, Guo Beibei, Ma Ruguang, Zhu Yufang, Wang Jiacheng
School of Materials Science and Engineering, University of Shanghai for Science and Technology Shanghai 200093 P. R. China.
State Key Laboratory of High Performance Ceramics and Superfine Microstructure, Shanghai Institute of Ceramics, Chinese Academy of Sciences Shanghai 200050 P. R. China
RSC Adv. 2020 Apr 21;10(27):15707-15714. doi: 10.1039/d0ra01705a.
Due to the dilemma of rapid consumption of fossil fuels and environmental pollution, development of clean, efficient and renewable energy conversion and storage technology has become an urgent need. Supercapacitors and hydrogen-oxygen fuel cells as typical representatives have become the focus of scientific research, in which the electrode materials are of much importance to their improved activity. In this work, a series of porous carbons (PCs) with high specific surface areas were prepared using natural coals as carbon precursors coupled with KOH activation. The effects of the mass ratio of coal and KOH as well as different activation temperatures on the microstructures of the PCs and electrochemical properties were studied in detail. The optimal PC4 (KOH: coal = 4) possessed a high specific surface area (SSA) of 2092 m g and a well-developed microporous structure. As the electrocatalyst, it exhibited a positive onset potential of 0.88 V ( reversible hydrogen electrode (RHE)) and half-wave potential of 0.78 V ( RHE) towards the oxygen reduction reaction (ORR) in an alkaline solution. PC4 also showed the highest specific capacitance of 128 F g at a current density of 0.5 A g among all the samples in this work. The relatively good performance of PC4 resulted from its well-developed microporous structure and large SSA, enabling fast mass transfer of electrolytes.
由于化石燃料快速消耗和环境污染的困境，开发清洁、高效和可再生的能量转换与存储技术已成为迫切需求。超级电容器和氢氧燃料电池作为典型代表已成为科研焦点，其中电极材料对其活性的提高至关重要。在这项工作中，以天然煤为碳前驱体并结合KOH活化制备了一系列具有高比表面积的多孔碳（PCs）。详细研究了煤与KOH的质量比以及不同活化温度对PCs微观结构和电化学性能的影响。最优的PC4（KOH:煤 = 4）具有2092 m²/g的高比表面积（SSA）和发达的微孔结构。作为电催化剂，它在碱性溶液中对氧还原反应（ORR）表现出0.88 V（可逆氢电极（RHE））的正起始电位和0.78 V（RHE）的半波电位。在这项工作的所有样品中，PC4在0.5 A/g的电流密度下还表现出128 F/g的最高比电容。PC4相对良好的性能源于其发达的微孔结构和大的比表面积，使得电解质能够快速传质。
