氮掺杂生物炭的制备与应用研究进展

Research progress on preparation and application of nitrogen-doped biochar

生物质不仅储量丰富、分布广泛且可再生,是一种亟待高值化利用的资源。将其炭化后制备的生物炭具有良好的理化性质,常被用于吸附污染物、制作电极材料。但与活性炭相比,生物炭存在孔隙结构欠发达、表面官能团种类和数量稀少等问题,其应用受到了很大限制。通过对生物炭进行N元素掺杂改性制成N掺杂生物炭(NBC)可丰富生物炭孔隙结构和表面活性位点,提高吸附、导电和催化性能。本文综述了国内外近几年来关于NBC的制备/改性方法(热解法、活化法、水热法、模板法和后处理法等)及其优点和局限性,梳理了各方法得到的NBC的形貌结构及表面化学特征,概括了氮掺杂对NBC的催化、吸附、电化学性能的影响及NBC在各领域的应用。以“制备-结构-性能及应用”相结合的思路,从NBC的应用角度逆向出发,思考如何通过探究N掺杂机理和优化制备方法,来充分发挥NBC在各领域中的应用价值,并对今后该领域的研究发展提出了展望。

Biomass is abundant,widely distributed and renewable,and can be used in high value resources.The biochar obtained after carbonization of biomass has good physical and chemical properties,and is often used to adsorb pollutants and make electrode materials.Compared with activated carbon,there are many problems such as underdeveloped pore structure and scarcity of surface functional groups,limits the application of biochar.Nitrogen doping can enrich biochar pore structure and surface activity sites,and endow the N-doped biochar(NBC)with improved adsorption,conductivity and catalytic performance.In this paper,preparation/modification methods of NBC,such as pyrolysis,activation,hydrothermal,template and post-treatment method,along with their benefits and drawbacks were reviewed.The morphological structure and surface chemical characteristics of NBC obtained by each method were summarized.And the applications of NBCs in catalysis,adsorption and electrochemical energy storage fields were generalized.With the"preparation-structure-characteristics and application"combined conception,started from the perspective of NBC application,this paper discussed how to maximize the application value of NBC by investigating the N-doping mechanism and improving the preparation method,and then presented references and recommendations for further research and development in this field.