Synthesis And Electrochemistry Of Ordered Mesoporous Carbon-based Materials

Ordered mesoporous carbon (OMC) possesses promising properties such as highsurface area, large pore volume, good electrical conductivity and electrocatalyticactivity for a variety of redox reactions, so OMC attracts considerable attention inthe field of electrochemical sensors. OMC also can be explored as a catalyst supportto confine metal particles, due to its high surface area and pore volume. The orderedmesoporous framework of OMC can be used as anoreactors to avoid nanoparticlesaggregation, allowing for the obtainment of high metal dispersion. In general, smallsize catalysts have been found to be more active than large ones, because largesurface to volume ratios of small particles are favorable to enhancing catalyticactivities. The ordered mesoporous carbon and nanoparticles exhibit differentexcellent properties, so the composite material which is the combination of OMCand nanoparticles exhibit more excellent properties and used in the field of catalysisand electroanalysis. We have investigated the synthesis of OMC and the compositematerials based on it and their electrochemistry. The work was summarized asfollows:(1) In this study, a novel ordered mesoporous carbon (OMC) with high surfacearea (1600m2/g), large pore volume (1.6cm3/g) and open pore structure wassuccessfully prepared. As a novel electrode material, the catalytic activities of OMCtowards simultaneous electrooxidation of tyrosine (Tyr) and L-cysteine (CysH) wereinvestigated by differential pulse voltammetry. Significantly, well separatedoxidation peaks of Tyr and CysH were firstly observed at physiological pH at theOMC electrode. Selective determination of Tyr was carried out in the presence ofCysH. More importantly, well distinguishing Tyr from ascorbic acid, dopamine, uricacid, epinephrine was also demonstrated, suggesting an excellent anti-interferenceability of this Tyr sensor. (2) Ultrafine CuO nanoparticles (UCNs) were well-isolated in the nano-channelsof ordered mesoporous carbon (OMC) via a double solvent procedure. In thisapproach, uniform OMC meso-channels of large surface area acted as nanoreactorsembedded with small nanoparticles. n-Hexane was used to disperse OMC, andCu(NO3)2aqueous solution served as a precursor to fill the nano-channels. Theinterfacial force between double solvents facilitated the precursor filling within theOMC mesopores, and the subsequent heat treatment triggered in situ isolation ofUCNs within OMC porous channels. UCNs have good catalytic performance andthe remained ordered porous structure of UCNs@OMC is beneficial for electronictransmission. The combination the unique properties of CuO nanoparticles and theordered mesostructure of OMC matrix guarantee the excellent electrocatalysis forglucose. The glucose sensor based on UCNs@OMC exhibits good sensitivity andselectivity.(3) CuO nanoparticles isolated in the nano-channels of mesoporous silica(SAB-15) via a double solvent procedure. Copper containing ordered mesoporouscarbon (Cu/OMC) samples is prepared by using a hard-templated method:CuO/SBA-15as the hard template and furfuryl alcohol as carbon precursor.Cu/OMC has high surface area, large pore volume and open pore structure, highlydispersed copper is confined on the walls of OMC, so Cu/OMC possesses excellentelectrocatalysis performance. An Cu/OMC based glucose sensor was fabricated andtested exhibiting good sensitivity and selectivity.