Production and applications of N-doped carbons from bioresources: A review

N-doped and metal-N-doped carbons are receiving increasing attention for environmental and electronic applications. Modifications of carbons such as biomass-derived char by N-doping allow for modulating carbons' acid-base character, adsorption capacity, catalytic performance, and electrochemical properties (e.g., electrical conductivity and capacitance). N-doped carbons are obtained from the thermal co-processing of C-rich and Nrich sources (e.g., lignocellulosic biomass, proteins, and ammonia). Although the literature is abundant in papers on producing heteroatom-doped carbon nanotubes, carbon fibers, and other high-value carbonaceous products from non-renewable sources, the number of articles reporting N-doped chars from bioresources is more limited. Thus, this paper aims to review synthesis processes and activation strategies to produce N-doped carbons from biomass resources and the uses of the resulting materials. Pyrolysis and hydrothermal carbonization offer opportunities to obtain relatively cheap, environmentally friendly N-doped carbonaceous materials with tailored properties for environmental and electronic applications. The role of the Maillard reactions in integrating N into carbonaceous products' structure is also discussed. This paper summarizes desired char properties and the relationship between chemical composition and application performance.