Preparation Of Nitrogen-rich Porous Graphene And Its Application

Graphene is the first synthetic two-dimensional?2D?atomic crystal.It has attracted immense attention because of its excellent properties,including stiffness,strength,elasticity,high thermal conductivity,extremely high electron mobility,and tunable band gap.Being such a fascinating all-in-one material,graphene can replace other materials in many applications and bring about technological breakthroughs.Especially,nitrogen-doped porous graphene is one of the members of the three-dimensional heteroatom doping material of graphene,due to its excellent electrical conductivity,high specific surface area,large pore volume,and excellent hydrophilicity make suitable for energy storage,catalysis,and environmental adsorption.The field has an irreplaceable role.However,there are still many key problems that need to be solved in the synthesis of nitrogen-doped porous graphene materials at the present stage:the problem of template removal for constructing three-dimensional graphene structures and the difficulty in controlling the uniformity and low content of nitrogen atoms in the process of introduction.Therefore,it is still challenging to develop a simple,low-cost and high-efficiency method for preparing nitrogen-doped three-dimensional graphene materials.We report a protocol for g-C₃N₄ template-directed in-situ fabricating nitrogen-rich porous graphene-like carbon sheets?NPGCs?by using plasma-enhanced chemical vapor deposition followed with high-temperature pyrolysis process,which totally avoids the postsynthetic template removal.By scanning and transmission electron microscopy,the morphology,structure and Raman spectroscopy characterization methods,we characterize the NPGCs which integrate a range of intriguing features including highly conductive interconnected structure(693 S·m^-1),abundant mesoporous with ultrahigh pore volume(4.35 cm³·g^-1),large specific surface area(1277 m²·g^-1),high N doping?8.75 wt%?,and good wettability.In order to verify the application prospect of the prepared material,this paper further studied the performance of the material as electrode material and dye adsorbent.As supercapacitor electrode,the NPGCs exhibit a quite encouraging specific capacitance of 261 F·g^-1 at 1 A·g^-1,excellent rate capability(189 F·g^-1 even at 100A·g^-1),and outstanding cycle performance(97%capacitance retention at 10 A·g^-1 after20000 cycles),which outperforms most carbon-based materials reported to date.Moreover,the assembled supercapacitors deliver a high power density of 28.4 kW·kg^-1with a energy density of 6.53Wh·kg^-1 at 100 A·g^-1.And the adsorption behaviors of NPGCs-850 for anionic dye methyl orange?MO?were investigated,which are fit excellent for the Langmuir isothermal adsorption equation,and the the maximum adsorption capacity?q_m?is 467.3 mg·g^-1 for MO.The material exhibited high adsorption capacity for MO at room temperature.According to the results of characterization,the main features of NPGCs-850,like large pore volume and abundant nitrogen doping on the surface,should be related to the excellent adsorption property for MO.Therefore,this work provides a new avenues for developing efficient nitrogen-doped porous carbon materials in a facile and viable way.