| Metal coordination polymers are a new member of the family of crystalline porous materials.As a branch of metal organic framework(MOF)materials,metal organic phosphonic acid coordination polymers have received extensive attention in the fields of adsorption,separation and catalysis in recent years due to its structural stability and excellent proton conductivity.However,due to the multidentate coordination characteristics of organophosphonic acid ligands and the complexity of synthetic chemistry of organophosphonic acid coordination polymers,it is difficult to understand and realize their synthesis controllability,structural designability and formation mechanism.In this paper,a series of metal coordination polymers and their derived electrocatalytic materials were designed and synthesized through optimizing the synthesis process and ligand competition by amino tris(methylene phosphonic acid)(ATMP),which is cheap,easily available,highly modifiable and stable.From the perspective of physics and chemistry,the mechanism of ATMP ligand on the morphology and size,and the stability of the active center of the synthesized electrocatalytic material have been studied.Based on the simultaneous regulation of the catalytic process and material transport kinetics,the structure-activity relationship between the active site structure and catalytic performance of electrocatalyst materials have been explored,Moreover,the high-performance catalytic mechanism has been clarified.Finally,the application in engineering,including biosensor,water splitting and Zinc-air batteries have been preliminary expanded.The main work and results of the paper are as follows:1.ATMP Derived Co(PO3)2-based Materials as Highly Active Catalyst for ORRAn innovative strategy based on ATMP as chelating agent for cobalt-metaphosphate coordination polymer is reported to one-pot synthesis of a novel precursor in methanol for ORR electrocatalyst.Carbonization of the precursor at 900 ? at N2 atmosphere results in the feasible formation of cobalt metaphosphate based composite(Co(PO3)2/NC).A further step in the thermal cleavage at 650 ? at air for 4h,Co(PO3)2/NC can be finally transformed into inorganic Co(PO3)2.This obtained Co(PO3)2/NC nanocomposite exhibits superior electrocatalysis to Co(PO3)2 with an enhanced onset potential(0.906 V vs.RHE)and diffusion limiting current(5.062 mA cm-2),which are roughly close to those of commercial 20%Pt/C(0.916 V vs.RHE,5.200 mA cm-2).Advanced spectroscopic techniques and density function theory(DFT)calculations are applied to confirm the physical properties and the main catalytically active center of Co(PO3)2/NC.2.ATMP Derived M2P2O7-based Materials for Bifunctional Electrocatalysts for ORR and HERA novel bimetal coordinated polymer was prepared feasibly in polyvinyl pyrrolidone(PVP)aqueous solution using ATMP and 2-methylimidazole(2-Me Im)as ligands with the ratio of 2:5,Co2+and Zn2+as metal centers.Based on the concept of acid-base neutralization reaction,the proton-transfer induced“deprotonation and protonation”for ATMP and 2-Me Im,respectively.Thus,the coordination was dominated by the deprotonated ATMP.Owing to also partial of protonated 2-Me Im adsorbed as“counter ions”,carbonization of the obtained precursor at 800? under N2 atmosphere endows the pyrolysis product with nitrogen-doped carbon supported metal pyrophosphate(M2P2O7@NC).Thus,the resulting M2P2O7@NC exhibits the enhanced and durable ORR and HER performance.For ORR in 0.1 M KOH,an enhanced onset potential(0.925 V vs.RHE)and diffusion limiting current(6.100 mA cm-2)can be obtained comparable to that of Pt/C(0.916 V vs.RHE,5.427 mA cm-2).For HER in 0.5 M H2SO4,it only needs an over potential of 180 mV to realize a current density of 10 mA cm-2.3.ATMP Derived Co P-based Materials as Synergetic Trifunctional Electrocatalyst for ORR,OER and HERA facile strategy of“Lewis acid-base interactions”was introduced using ATMP and Melamine as Lewis acid and base ligand respectively to synthesize a novel cobalt based organophosphonic acid coordination polymer.ATMP and Melamine are combined through hydrogen bonding,which greatly weakens the chelating ability of cobalt ions and ATMP.Meanwhile,the introduced Melamine is rich in carbon and nitrogen allows the cobalt-organophosphate complex to be placed in a strong reducing atmosphere during the high-temperature calcination process to achieve the purpose of in-situ phosphating.The resulted calcined product(N-Co P/NC)exhibits the enhanced and durable ORR,OER and HER performance.For ORR in 0.1 M KOH,an enhanced onset potential(0.910 V vs.RHE)?half wave potential(0.910 V vs.RHE)and diffusion limiting current(6.280 mA cm-2)can be obtained which comparable to that of Pt/C.For OER in 1 M KOH,it only needs an over potential of 153 mV(vs.RHE)to realize a current density of 10 mA cm-2.For HER in 0.5 M H2SO4,an overpotential of 160 mV(vs.RHE)is required to drive 10 mA cm-2.Moreover,DFT calculations reveal the catalytic pathway of N-Co P/NC.4.ATMP Derived Conductive Polymer Hydrogel Scaffold for Electrochemiluminescence BiosensorA novel three-dimensional(3D)conductive polymer hydrogel of polyaniline(PAni)was feasibly prepared using aniline(Ani),ATMP and ammonium persulfate((NH4)2S2O8)as monomer,gelatinizing agent and oxidizing agent,respectively.Protonation of aniline can be achieved by ATMP,inducing good conductivity of the obtained hydrogel.ATMP remained the chelating abilities in the conductive hydrogel,enabling further immobilization with silver nanoparticles(Ag NPs)functionalized by a luminol derivative,N-(aminobutyl)-N-(ethylisoluminol)(ABEI).ABEI-Ag@PAni-ATMP exhibited an enhanced performance of solid-state electrochemiluminescence(ECL).Integrated with xanthine oxidase(XOD),the proposed biosensor can be applied in the detection of xanthine via in-situ generated hydrogen peroxide(H2O2),and present a low detection limit of 9.6 nM,a wide linear range(from 0.01 to200?M).The biosensor also shows good detection performance for xanthines in fish flesh and has good stability. |
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