| The carbon material has good prospect in the waste treatment, the electrode material, biological carrier, etc. because of its excellent absorption, good thermal stability, high mechanical strength and other characteristics. Traditional raw material for the preparation of carbon mainly is oil, coal and other fossil fuels. With the development of human society, the world’s energy structure is changing and fossil resource consumption is slowdown in growth while the proportion of renewable resources is growing which makes it becomes a hot research for scholars from various countries. As facing an unprecedented energy crisis in China, the research and development of a new energy with efficient and renewable is imminent.In recent years, biomass as a new renewable resource, because of its advantages of low cost, huge reserves and environmentally friendliness, has been widely concerned. Through different methods such as thermal decomposition method, microwave carbonization method, hydrothermal method and so on, a large number of biomass can be converted into functional carbon material with active functional groups, large surface area and micro porous structure, and widely used in the field of waste adsorption and super capacitor. Hydrothermal carbonization method as a moderate carbonization method has many advantages including simple processing equipment, the waste biomass carbon fixation with high efficiency, and low energy consumption, compared with high temperature carbonization method.This method has been shown that it can convert biomass into high functional carbon material.Corn straw and phoenix tree leaves as sources of widespread, low-cost biomass, the inappropriate treatment not only pollute the environment, but also is a waste of raw material resources. In this paper, with corn stalk cores and phoenix leaves as carbon source, hydrothermal method and KOH activation method was operated to prepare porous biomass carbon materials. The prepared product was used as adsorbent and super capacitor electrode material.The hydrochar was prepared by hydrothermal carbonization method with the corn stalk core as carbon source. The optimum conditions were obtained by orthogonal test.The results showed that the prepared hydrochar was formed of a certain degree of graphitization. The hydrochar exhibited the good performance for the adsorption to Cr (VI), and the adsorption capacity was 1.182 mg/g;PVP was utilized to modify the hydrochar. The modified carbon material is irregular sphere with rougher surface and bigger specific area. It has greater adsorption efficiency. The adsorption capacity of Cr (VI) was 2.264 mg/g;After activated by KOH, microporous honeycomb structure was obtained with higher degree of graphitization. The porous carbon material exhibited good electrochemical performanceused used as electrode materials for super capacitor. The maximum specific capacity of the porous carbon material electrode was 315.5 F/g with the current density of 0.5 A/g. When the current density was 20 A/g, porous carbon electrode material had excellent cycle characteristic.81.8% of specific capacitance was retained after 2000 times cycling.Using phoenix tree leaves as raw material, carbon microsphere with the particle size of 1-3 μm and a certain degree of graphitization was obtained by hydrothermal carbonization method. The carbonaceous material had good adsorption properties to hexavalent chromium.Carbon material obtained by hydrothermal method with phoenix tree leaves as raw material was activated by KOH. The product had honeycomb porous surface structure, and a higher degree of graphitization. It also showed excellent performance working as super capacitor electrode material. The specific capacitance of the porous carbon material electrode was 365 F/g at a current density of 0.5 A/g. When the current density was 20 A/g,91.7% specific capacitance was retained after 2000 cycles.The sample showed good cycle performance. |
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