水热碳化制备榴莲壳复合焦及其电化学性能  

Durian shell composite biochar prepared by hydrothermal carbonization and its electrochemical properties

作　　者：董向元 张恒瑞 陈祥 李硕 郭淑青 Dong Xiangyuan;Zhang Hengrui;Chen Xiang;Li Shuo;Guo Shuqing(School of Energy and Power Engineering,Nanjing Institute of Technology,Nanjing 211167,China)

机构地区：[1]南京工程学院能源与动力工程学院,南京211167

出　　处：《农业工程学报》2021年第8期316-322,共7页Transactions of the Chinese Society of Agricultural Engineering

基　　金：国家自然科学基金项目(51206194);南京工程学院引进人才科研启动基金(YKJ201811和YKJ201812)。

摘　　要：为研究水热碳化处理对榴莲壳复合改性焦性能的影响,将榴莲壳原料及250℃、10 h制备的水热焦分别与层状氢氧化镁铝(Mg/Al LayeredDoubleHydroxide,MgAl-LDH)复合,获得榴莲壳与MgAl-LDH复合焦MgAl-LDH@DP和榴莲壳水热焦与MgAl-LDH复合焦MgAl-LDH@HC,分析比较两种焦的特性以及电化学性能。结果表明,同MgAl-LDH@DP相比,MgAl-LDH@HC有更强的活性含氧官能团,对LDH纳米片有较好的分散性。MgAl-LDH@DP焦表面有大量针状结构,而MgAl-LDH@HC呈不规则片状结构,表面疏松多孔,BET(Brunauer-Emmett-Teller)比表面积为62.96 m~2/g,平均孔径14.81 nm,BJH(Barrett-Joyner-Halenda)累积吸附孔容积为0.24 cm^(3)/g,均高于前者,更有利于电荷储存和电子传输。在KOH溶液为电解质、复合焦为工作电极的三电极系统中,循环伏安曲线和恒电流充放电曲线分别接近矩形和三角形,同MgAl-LDH@DP相比,MgAl-LDH@HC有较好的电容特性和倍率性能,低频时交流阻抗曲线斜率更大,离子扩散阻力相对较小,有潜力作为超级电容器电极材料应用。Hydrothermal Carbonization(HTC)can widely be used to convert the dry/wet biomass(green and renewable materials)directly into the hydrochar with a rich oxygenated functional group(a high value-added carbonaceous material).There is a promising potential application of hydrochar in energy storage in recent years.Nevertheless,a relatively low capacitance of hydrochar has limited to serve as electrode materials.Recently,Layered Double Hydroxide(LDH)has also been considered as one of the most promising electrode materials,due to the high energy density,dispersed active sites,and cheap raw materials.However,the LDH extension has been confined to a relatively weak electrical conductivity and mechanical stability.Therefore,combing the LDH and hydrochar may be a promising trade-off to develop high-efficient electrode materials.Herein,the hydrochar(HC)was prepared through HTC using durian shell(DP)at 250℃and 10h.Then magnesium aluminum Layer Double Hydroxides(MgAl-LDH)were decorated on the surface of HC,in order to obtain the MgAl-LDH@HC composite.MgAl-LDH was also decorated on the surface of DP raw materials to explore the effect of HTC process on the performance of the composite.The microstructure of MgAl-LDH@DP and MgAl-LDH@HC were characterized using X-ray Diffraction(XRD),X-ray Photoelectron Spectroscopy(XPS),and scanning electron microscopy(SEM).An electrochemical test was also carried out for the properties of the composite.The results show that the cellulose crystal structure of the durian shell was destroyed after HTC treatment,where the carbon content of HC was 70.29%.The XRD pattern of MgAl-LDH@HC presented the sharp peaks at 11.23°,22.64°,33.98°,and 60.11°of 2θ,being assigned to the(003),(006),(012),and(110)planes,respectively,indicating a typical hydrotalcite-like structure.The XRD spectra also illustrated that the MgAl-LDH was successfully decorated on the surface of HC.In MgAl-LDH@DP,there were strong peaks of cellulose crystallinity structure at 22.37°and 34.39°,in spite of the characteristic peaks

关 键 词：生物炭 水热焦 电化学性能 榴莲壳 层状双氢氧化物 

分 类 号：TK6[动力工程及工程热物理—生物能]