【摘要】：以天然可再生的生物質(zhì)為原料制備炭材料,不僅可減少人類對(duì)化石能源的需求,還可緩解因焚燒生物質(zhì)而引起的環(huán)境污染問(wèn)題。本文以核桃殼和柚皮為前軀體,在稀硫酸的催化作用下,采用一步水熱炭化的方法制備水熱炭,并考察其對(duì)六價(jià)鉻的吸附性能;采用KOH活化水熱炭制備多孔炭,并研究其在超級(jí)電容器中的電化學(xué)性能。主要內(nèi)容如下:(1)核桃殼水熱炭和柚皮水熱炭的最合適的制備條件為分別在180℃、190℃下水熱12h,此時(shí)水熱炭收率分別為50.69%、50.13%,碳含量分別為66.26%、60.22%;比表面積分別為21m2/g、79 m2/g,孔徑主要分布在2~24nm之間,是典型的介孔材料;水熱炭主要由粒徑大小不一的炭微球組成,表面有很多含氧官能團(tuán)。(2)水熱炭在吸附六價(jià)鉻的過(guò)程中受pH影響較大,酸性條件下效果較好;隨水熱炭加入量增加,吸附率增加,吸附量先增加后減小;隨六價(jià)鉻濃度升高,吸附量逐漸增加,吸附率先增加后減小;吸附平衡時(shí),核桃殼水熱炭和柚皮水熱炭對(duì)六價(jià)鉻的吸附率分別為98.32%、99.03%;吸附動(dòng)力學(xué)和等溫吸附數(shù)據(jù)研究結(jié)果表明,水熱炭的吸附過(guò)程符合準(zhǔn)二級(jí)動(dòng)力學(xué)模型和Freundlich模型。(3)隨堿碳比、活化溫度的增加,多孔炭的比表面積和總孔容先增加后減小,中孔率逐漸增加;同常規(guī)熱解炭化活化制備的炭材料相比,核桃殼多孔炭和柚皮多孔炭的的比表面積分別增加了13.62%、16.79%,總孔容分別增加了14.37%、11.43%;多孔炭均由許多表面光滑的炭微球和不規(guī)則的塊狀結(jié)構(gòu)組成;其形成分為低溫“汽化”和高溫“活化”兩個(gè)階段。(4)核桃殼多孔炭和柚皮多孔炭作為電極材料,在3mol/L KOH電解液中具有良好的電容特性,質(zhì)量比電容最大分別可達(dá)284F/g、260F/g,同常規(guī)熱解炭化活化制備的炭材料相比,質(zhì)量比電容分別增大了36.54%、20.37%。
[Abstract]:Using natural renewable biomass as raw material to prepare carbon materials can not only reduce human demand for fossil energy but also alleviate the environmental pollution caused by burning biomass. In this paper, using walnut shell and pomelo peel as precursors, hydrothermal carbon was prepared by one-step hydrothermal carbonization under the catalysis of dilute sulfuric acid, and its adsorption property for hexavalent chromium was investigated. Porous carbon was prepared by KOH activated hydrothermal carbon. The electrochemical performance of the supercapacitor was studied. The main contents are as follows: (1) the most suitable conditions for the preparation of hydrothermal carbon from walnut shell and pomelo peel are as follows: water heating at 180 鈩，

本文編號(hào)：2250886