Porous Carbon Nanocomposite Materials:Preparation And Electrocatalysis Application

Porous carbon is a new kind of carbon materials with high specific surface area,high electronic transmission ability,good mechanical strength and abundant porous structures.These advantages make porous carbon more accessible for the active sites,faster for the mass transfer and higher for electron conductivity.At the mean time,the active sites inserted in porous carbon are more stable owing to the unique porous structure.Therefore,porous carbon materials attract more and more attentions these years in various areas,including catalyst supports,fuel cells,supercapacitors and so on.In the introduction,the classification,methods of synthesis,functionalization and electrochemical applications of porous carbon materials were summarized.Based on the previously study,we prepared some novel porous carbon(including porous graphene(PG),ordered mesoporous carbon(OMC),macroporous carbon(MPC),mesoporous carbon nanospheres(MCS),etc)and their nanocomposite materials.We also studied the electrocatalytic application,the the main content is as follows:(1)We developed a novel biosensor based on highly exposed Pt nanoparticles(Pt NPs)decorated PG for the reliable detection of extracellular hydrogen peroxide(H2O2)released from living cells.The commercially available low-cost hydrophilic CaCO3 spheres were used as template for preparing PG.The porous structure provided larger surface area and more active sites.Due to the porous structure of PG,the Pt NPs supported on PG were not secluded by aggregated graphene layers and were highly exposed to target molecules.Electrochemical performances of the Pt/PG nanocomposites modified glassy carbon electrode(GCE)were investigated.The electrocatalytic reduction of H2O2 showed a wide linear range with a high sensitivity and a low limit of detection(LOD).Moreover,the Pt/PG/GCE exhibited excellent anti-interference property,reproducibility and long-term storage stability.Because of these remarkable analytical advantages,the constructed sensor was used to determine H2O2 released from living cells with satisfactory results.The superior catalytic activity makes Pt/PG nanocomposites a promising candidate for electrochemical sensors and biosensors design.(2)A novel porphyrinic iron metal-organic framework(pFeMOF)-decorated OMC was developed to detect H2O2 released from viable cells.The pFeMOF/OMC hybrid materials were synthesized via a simple one-step hydrothermal method.Because of the mimic peroxidase property of pFeMOF,amplified electrochemical signal could be obtained.The carbon skeleton of OMC revealed a function of restriction for the growth of pFeMOF crystallites,resulting in more active sites to reduce H2O2.The increased amount of mesopores brings faster diffusion.Moreover,the electrical conductivity and stability has been improved due to the introduction of OMC.The electrocatalytic reduction of H2O2 displayed excellent analytical performances.The as-prepared biosensor was applied to detect H2O2 released from living cells with satisfactory outcome.These results display that this new nanocomposite has the potential to fabricate electrochemical sensing platform for nonenzymatic biosensing.(3)The pFeMOF was combined with different kinds of carbon matrices,including porous graphene(PG),ordered mesoporous carbon(OMC)and macroporous carbon(MPC)via a simple one-step hydrothermal method.The introduction of carbon substrates improves the electrical conductivity and stability of pFeMOF.The presence of carbon also reduces the size of pFeMOF crystallites,leading to more active sites.The catalysts were used to electrocatalysis of hydrogen evolution reaction(HER)and the reduction of H2O2.Electrochemical measurements show that pFeMOF/PG has better electrocatalytic efficiency than pFeMOF/OMC,pFeMOF/MPC and pFeMOF.The HER on pFeMOF/PG displays a small onset potential,a low Tafel slope and a small over-potential.The linearity range of H2O2 is wide and the sensitivity is high.Such splendid performances may be attributed to the crumpled structure of PG leading to evenly and smaller pFeMOF.Furthermore,abundant hierarchical pores of pFeMOF/PG result in larger electrochemically surface areas.Our work may provide a new approach to design efficient nonprecious metal catalysts.(4)A kind of novel metal-free mesoporous carbon nanospheres/graphene(MCS/GR)composite was prepared through an aqueous synthesis route,which was used to measure the level of doxorubicin(DOX).The experiment results show that MCS/GR based sensor has good detection effects for DOX with large linear range(0.01-10 ?M)and low limit of detection(1.5 nM).At the meantime,the MCS/GR modified electrode has good selectivity,reproducibility and long-term stability for DOX.Furthermore,the as-prepared material can be used to detect DOX in real human serum.The improved catalytic effects can be attributed to the following reasons.The introduction of MCS improves the agglomeration of graphene sheets,leading to lager surface area and more active sites.Furthermore,the abundant mesopores enhance the catalytic efficiency.The procedure of this metal-free catalyst is mild and low-priced.It may provide a new way to prepare DOX sensors.