High-yield production of non-layered 2D carbon complexes: Thickness manipulation and carbon nanotube branches for enhanced lithium storage properties

摘要

Non-layered two-dimensional(2 D)carbon complexes manifest great potential in energy-related applications owing to their exotic electronic structures,large electrochemically active surface,and intriguing synergistic effects.However,reliable method for mass production and thickness manipulation of 2 D carbon complexes remains great challenges.Here,inspired by blowing chewing gum into bubbles,a“tailored gel expanding"strategy is proposed for high-yield synthesis of non-layered 2 D carbon complexes with tailored thickness from~12 nm to~1 lm,by controllable pyrolysis of metal-polymeric gel with adequate crosslinking degree.The key feature for thickness manipulation is introducing NH4 NO3 in sol-gel process,which tailors the expansion behavior of gel precursor during subsequent pyrolysis.Various of 2 D sheets with intimately coupled N,O-doped carbon(NOC)and Ni Co-based(Ni Co,(Ni Co)S_(2),(Ni Co)Se_(2),Ni Co_(2)O_(4),(Ni Co)(PO_(3))_(2))nanocrystals are obtained on a large scale and without any impurities.Moreover,these 2 D products are branched with in-situ grown CNTs on the surface,accelerating electrons transfer and preventing the nanosheets from stacking.As a demonstration,the 2 D(Ni Co)S_(2)/NOC with optimized thickness manifests excellent lithium storage properties in both half and full cells.This method paves a new path for massive and controlled production of non-layered 2 D materials with tailored thickness and robust structure stability for energy-related applications.