Abstract:

Based on the preparation of high microporous sargassum-based activated carbon by KOH activation, and the reaction kinetics of carbon dioxide and carbon, sargassum-based activated carbon is modified by carbon dioxide, the pore structure and electrochemical properties of sargassum-based activated carbon modified are studied. The results show that: the specific surface area of the modified sargassum-based activated carbon decreases significantly from 3155m²/g to 2776m²/g, but the mesoporous specific surface area of modified activated carbon increases significantly from 181m²/g to 538m²/g, and the mesoporous content of activated carbon with pore size between 2—8nm increases significantly, the decrease of specific surface area is due to the decrease of microporous specific surface area. After modification, the microporous content of activated carbon decreases, and the microporous structure with pore size between 0.4—0.6nm basically disappears, but the microporous structure with pore size between 0.6—1nm increases, and the average pore size of activated carbon increases. The specific capacitance and rate performance of modified sargassum-based activated carbon are improved significantly. After carbon dioxide modification, the pore structure and electrochemical properties of sargassum-based activated carbon are synergistically optimized.

Key words: activated carbon, carbon dioxide, electrochemistry, pore structure, optimization

摘要：

以马尾藻为原料，采用KOH活化法制备了高微孔率马尾藻基活性炭，结合二氧化碳与碳反应动力学机理，对马尾藻基活性炭进行二氧化碳扩孔改性，研究了二氧化碳改性对高微孔率马尾藻基活性炭孔结构特性和电化学性能的影响。研究表明：二氧化碳改性后马尾藻基活性炭的比表面积明显减小，由3155m²/g减小至2776m²/g，但是改性后活性炭中孔比表面积明显增大，由181m²/g增大至538m²/g，活性炭孔径介于2~8nm的中孔含量明显增多，比表面积的减少是由于微孔比表面积的减少导致的。改性后活性炭微孔含量降低，孔径介于0.4~0.6nm的微孔结构基本消失，但是孔径介于0.6~1nm的微孔结构却有所增加，活性炭微孔平均孔径增大。改性后马尾藻基活性炭的比电容性能以及倍率性能得到明显提升。经过二氧化碳改性后，马尾藻基活性炭的孔结构和电化学性能得到协同优化。

关键词: 活性炭, 二氧化碳, 电化学, 孔结构, 优化