Biligand metal-organic coordination polymer to prepare high N-doped content and structure controllable porous carbon with high-electrochemical performance

N-doped content, N species and microstructure are crucial factors to control the energy storage ability of carbon-based materials. Herein, molecular engineering of metal-organic coordination polymers (MOCPs) by introducing two types of ligands to construct biligand MOCPs is proposed for the first time. Nitrogenous heterocyclic ligand 4,4'-bipyridine (BPD) and one of the aromatic amine ligands (p-phenyl-enediamine (PPD), 4,4'-diaminobiphenyl (AMP) and 3,3'-diaminobenzidine (DAB)) are selected to perform double-coordination reaction with different metal ions. Biligand MOCPs ([CO3(BPD)(2)(PPD)(10)Cl-6](n), [Ni(BPD)(AMP)(3)Cl-2](n) and [Co-3(BPD)(2)(DAB)(5)Cl-6](n)) have been successfully synthesized and employed as precursors to prepare N-doped porous carbons, referring as BPCco, BAC(Ni) and BDCco, respectively. Precise control over N-doped content, N species and microstructure has been fulfilled in these biligand MOCP derived N-doped porous carbons. As-prepared BPCco, BAC(Ni) and BDCco possess high nitrogen content of 11.39, 8.26 and 9.94 at.% and excellent gravimetric specific capacitance of 402, 316 and 303 Fg(-1), respectively. The BPCco, BAC(Ni) and BDCco assembled symmetric supercapacitors show outstanding energy density of 16.50, 13.38 and 12.98 W h kg(-1), respectively. The pioneering strategy to molecularly engineer MOCP paves a new avenue in structure controlling over porous carbons. This concept can be further broadened to design component of co-polymers, polymer blends and organic synthetic materials as precursors to obtain expected carbon structures and desired properties. (C) 2019 Elsevier Ltd. All rights reserved.