Two dimensional nanocarbons from biomass and biological molecules:Synthetic strategies and energy related applications

Two-dimensional(2D)carbon materials with ultrathin thickness,large lateral size,large surface area,accessible active sites and unique physical-chemical properties have been proven to be attractive electrode materials or catalysts for high-efficient energy storage and conversion materials.However,the conventional synthesis method for 2D carbon materials heavily depends on fossil-based feedstocks and goes through harsh conditions(e.g.,chemical vapor deposition),which are unsustainable and costly.Besides,the top-down method needs to use massive strong acids/oxidants,which is environmentallyunfriendly.Therefore,it is necessary to commit to seek green,sustainable and cost-effective approach for the synthesis of 2D carbon materials.As of now,biomass or biological molecules as carbon-rich resources have been viewed as a promising candidate for the 2D carbon material preparation owing to its abundance,renewability,nontoxicity and low-cost.Especially for nucleobases,as an emerging molecule have been shown great advantages for the construction of 2D materials guided by its multiple hydrogen-bonding interaction.Recently,our group have proposed a rather innovative strategy to produce 2D carbon materials by carbonization of nucleobases which has relatively high electrode potentials.These nucleobases can form planar network structure through hydrogen bonding interaction.Such hydrogenbonding can be stable at relatively high temperature,which confines C-C or C-N polymerization in a 2D plane.As a result,direct carbonization of nucleobases enables the formation of 2D carbon with highly sp2-conjugated and feature of heteroatom doping.This review systematically summarizes the recent development of the strategies to synthesize 2D sustainable carbon materials from biomass and biological molecules.The corresponding electrochemical applications such as lithium ion batteries,supercapacitors and fuel cell are selectively presented.At the end,the summary and future perspectives in this important field are provided to inspire further exploration.