Synthesis And Electrochemical Property Of Porous Carbon And Its Composite Materials

Porous carbon as a novel carbon materials, have received a great deal of attention in recent years. These porous carbon materials have been applied to gas separation, water purification, catalyst supports, and electrodes for electrochemical double layer capacitors and fuel cells due to their uniform pore sizes, high surface areas, and large pore volumes. Recently, porous carbon was widely used in electroanalysis and obtained well analysis results. Based on previous study results made by other researchers, this paper works over the electrochemical property of porous carbon material, including eletrocatalysis and electroanalysis. The main points of this dissertation are addressed as follows:1. 2-D ordered mesoporous carbon （OMC） was synthesized using SBA-15 as a template, and sucrose was used as a carbon source. The OMC modified electrode completed the simultaneous determination of dihydroxybenzene isomers. The results indicate that the isomer oxidation peaks become well resolved and are separated by about 150 mV for hydroquinone and catechol, 370 mV for catechol and resorcinol. This enables a highly selective and a simultaneous determination of dihydroxybenzene isomers at OMC modified electrode. Meanwhile, the OMC modified electrode also was used to detect riboflavin. The results showed that under an optimum condition （pH 7.0）, the OMC modified electrode exhibited excellent response performance to riboflavin with a high sensitivity 769μA mM-1 and a low detection limit 2×10-8 M. With good stability and reproducibility, the present OMC/GC electrode was applied in the determination of practical samples and satisfactory results were obtained.2. In order to improve detection capability, many other moleculars, such as inorganic moleculars and polymer, are incorporated in the structure of mesoporous materials. The PB/OMC composites were obtained after electrodepositing PB on the OMC and PB remains electroactivity. Compared to the known PB/GC electrode, the PB/OMC/GC electrode shows much wider pH adaptive range, much better electrochemical stability and larger response current to the reduction of H₂O₂. The electrocatalytic properties of PB were improved as the presence of OMC. The good results can be attributed the synergistic effect between OMC and PB. Therefore it would pave a new pathway to manipulate molecular entities of OMC by cooperation with functional inorganic electroactive compounds.3. The electroctalytic mechanism of OMC was investigated. Despite such potential catalytic capability of ordered mesoporous carbon, the electrocatalytic mechanism of OMC is not clear to date. There are just a few speculations that the high electrocatalytic activity observed at OMC is attributed to the presence of a large number of oxygen-containing functional groups and edge plane-like defective sites （EDSs） on the surface of OMC. In this work, we discussed in detail the influence of oxygen-containing functional groups for the electrocatalytic property of OMC. Ordered mesoporous carbon was further treated using different oxidant in liquid phase to create different oxygen-containing functional groups. To better understand the electrocatalytic property of the original and treated OMC, NADH and H₂O₂ as the probes were used to character the electrocatalytic activity of containing different oxygen-containing functional groups of OMC in this study. The results showed that OMC treated with HNO3 show better electrocatalytic activity for NADH oxidation and H₂O₂ reduction than original OMC. However, OMC treated with NaOH don’t display better electrocatalytic property than original OMC. It was concluded that the acidic groups on the surface of OMC is helpful to electrocatalytic property of OMC.4. The large mesoporous carbons （LMC） with a pore size about 50 nm were synthesized using nano-CaCO3 as a template. Electrocatalytic activity of the LMC was investigated using some some common electroactive molecules. Compared with CNT/GCE, the LMC/GCE displayed the higher electrocatalytic activity. It is attributed to the large pore size of LMC, which facilitate the diffusion of molecules.