氮掺杂生物炭材料的制备及其在环境中的应用

Preparation of nitrogen-doped biochar and its environmental applications

由生物质转化得到的生物炭材料因其成本低且环境友好被广泛用于环境领域,且对我国实现碳达峰与碳中和有积极的促进作用。非金属氮掺杂生物炭由于氮元素的引入,呈现表面碱度以及多吸附位点的特性,提高了其对污染物的去除性能,然而对氮掺杂生物炭材料的绿色可控合成及掺杂机理的关注不够。本文综述了近几年来国内外氮掺杂生物炭材料的制备及其在环境中的研究应用,梳理了氮掺杂生物炭材料中含氮官能团的类型和不同制备方法,含氮官能团包括吡啶N、吡咯N和石墨N等,其含量和类型受氮源、热解温度和时间的影响,阐明了其中的氮掺杂机理由氮源分解的中间产物、生物炭表面官能团和掺杂过程中的活化剂等因素决定。最后,对氮掺杂生物炭在环境方面的应用及作用机理进行探讨,并在此基础上提出未来研究高效氮掺杂生物炭的重点和研究方向,以期为氮掺杂生物炭在环境中的实际应用提供参考。

Biomass-derived biochar was widely used in environmental fields due to its low cost and environmental friendliness, and had a stimulative effect on achieving carbon peak and neutrality. Due to the doping of N, metal-free N-doped biochar possessed surface alkalinity and multi-adsorption sites, and the performance of pollutants removal was greatly improved. However, little attention had been paid to the green synthesis of N-doped biochar and the doping mechanism. Therefore, this paper summarized the domestic and international production of N-doped biochar and their environmental applications. The methods and N-containing functional groups were articulated. The groups included pyridinic N, pyrrolic N, and graphitic N. Their contents and types were influenced by the pyrolysis process of the N source. N doping mechanism, which was determined by the intermediates of N source decomposition, surface functional groups, and activator in the doping process, was explained. In addition, this paper discussed the environmental applications of N-doped biochar and their reaction mechanism. Based on these, we proposed the research direction of N-doped biochar to provide references for practical applications.