Preparation And Electrochemical Performance Of Macroporous Carbon Based On Biomass

Porous carbon (PC) with a large surface area, high porosity, well controlled poresize, good thermal conductivity and electronic conductivity has been widely used forthe applications of electrocatalysis, energy storage, electrochemical sensor,supercapacitor and catalyst. In general, the preparation approaches of porous carbonmaterials mainly contain three methods: soft template method, hard template methodor activation of carbon. However, these methods tend to have the shortcomings ofhigh cost and complicated preparation method, etc, which limit the industriallyscalable production and practical application of PC. Biomass is low cost, widely existin the nature, many of which have natural porous structure and the structure could bepreserved intact during carbonization. If we can use them, the problems existing in theunnatural porous carbon could be solved to some extent. Therefore, in this thesis, weprepared serials of three dimensional nanocomposites and different size of porouscarbon based on kenaf stem, a low cost and renewable environmental friendlybyproduct of agricultural crops with natural three dimensional structures, forconstructing electrochemistry sensors or supercapacitors. The main works include thefollowing three parts:1. A kind of Prussian blue (PB) nanoparticles (NPs)-carboxylicgroup-functionalized three dimensional carbonized kenaf stem (3D-KSCs)(PBNPs-3D-FKSCs) nanocomposite was prepared by carbonization and subsequentchemical synthesis. Scanning electron microscopy was used to characterize themorphology of PBNPs-3D-FKSCs and monitoring the situation of particles loadingand growth. Combined the merits of big surface area, good electrical conductivity,high porosity of3D-KSCs and excellent electrocatalytic activity to H2O2of PBNPs,the PBNPs-3D-FKSCs completed the determination of H2O2with high sensitive andlow detection limit. In addition, the composites material used in the preparation ofelectrode was massive, without crushing, is able to maintain its intact structure, isbenefit for solving the problem of the accumulation of nanoparticles on the carrier,has the certain enlightenment function to people prepare good electrode.2． A simple strategy for synthesis CuNi nanoparticles loaded3D-KSCs(CuNi-3D-KSCs) and Co nanoparticles loaded3D-KSCs (Co-3D-KSCs) wasdesigned by carbonization of KS-metal ion complex. Nitrogen adsorption isothermdata proved CuNi-3D-KSCs and Co-3D-KSCs have large surface area. SEM imagesshowed CuNi nanoparticles and Co nanoparticles uniformly embedded into the kenafstem and at the same time some holes appeared on it. CuNiNPs-3D-KSCs electrode showed fine response to the detection of glucose and it was also used to test actualsamples. Co-3D-KSCs electrode showed good electrocatalytic performance to theoxidation of amino acid with fast response time, wide linear range and low detectionlimit. The results embody the perfect combination of good catalytic activity of CuNi,Co and big surface area, good electrical conductivity of carbide kenaf stem.3. A green method for fabrication different pore size of porous carbon based onkenaf stem (PKSC) was designed by carbonization of KS-metal ion and hydrochloricacid corrosion. The porosity and big surface area of PKSC is conductive to theelectrolyte ions diffuse into the inner surface of electrode material, and make itselectric double layer capacitance increase. The experimental results showed PKSChave high electric double layer capacitance and lasting cycle characteristics. Beyondthat, the preparation method of PKSC is simple and low cost, make it has greatpotential application value in supercapacitor.