外交变磁场对碳纸原位负载MOFs衍生氮掺杂多孔碳OER性能的影响  

Effect of AC magnetic field on the OER properties of nitrogen-doped porous carbon derived from MOFs in-situ loaded carbon paper

作　　者：李玉玲 王垣力 李冬云 覃航 郭文明[1] 刘小磐[1] 高朋召[1] 肖汉宁[1] LI Yuling;WANG Yuanli;LI Dongyun;QIN Hang;GUO Wenming;LIU Xiaopan;GAO Pengzhao;XIAO Hanning(College of Materials Science and Engineering,Hunan University,Changsha 410082,China;College of Materials Science and Engineering,China Jiliang University,Hangzhou 310018,China)

机构地区：[1]湖南大学材料科学与工程学院,长沙410082 [2]中国计量大学材料科学与工程学院,杭州310018

出　　处：《粉末冶金材料科学与工程》2022年第2期224-236,共13页Materials Science and Engineering of Powder Metallurgy

摘　　要：采用溶剂热法在碳纸(carbon paper,CP)表面分别原位负载2种金属有机框架(metal organic frame,MOFs)前驱体(记为Zn-MOF-74和ZIF-8),经900℃高温热处理后前驱体衍生为氮掺杂多孔碳,得到氮掺杂多孔碳@CP电催化剂材料,分别记为CP-Zn-MOF-74-900-N_(2)和CP-ZIF-8-900-N_(2)。研究CP的组成、孔结构以及外磁场强度对电催化剂OER(oxygen evolution reaction,析氧反应)性能的影响。结果表明,原位负载的ZIF-8在CP的纤维表面形成致密的棱形十二面体颗粒层,热处理后在纤维表面形成均匀的纳米级氮掺杂碳材料。ZIF-8-900-N_(2)的比表面积为1559 m^(2)/g,孔径为0.57 nm,孔容为1.59 cm^(3)/g,具有最佳的磁性能和磁致发热性能。碳纸和氮掺杂多孔碳@CP材料中,CP-ZIF-8-900-N_(2)具有最小的OER过电势和Tafel斜率,分别为334 mV(电流密度为10 mA/cm^(2),经过iR矫正)和187 mV/dec(decade,十进)。当存在外磁场时,随磁场强度增大,催化剂的OER过电势先降低然后稳定不变,当外磁场强度为5.54×10^(−3) T时,CP-ZIF-8-900-N_(2)的过电势达到最小值,为316 mV(没有经过iR矫正),比未引入磁场时下降约20.4%,这主要归因于磁流体动力学效应导致气泡尺寸减小、气泡聚结增强,使得气泡从电极表面的解吸得到改善。In-situ loaded two kinds of precursors MOF(denoted as Zn-MOF-74 and ZIF-8)on the surface of carbon paper(CP)were successfully prepared by solvothermal method.After high temperature heat treatment,the precursors were derived into nitrogen-doped porous carbon,and the nitrogen-doped porous carbon@CP electrocatalyst material samples were obtained,named CP-Zn-MOF-74-900-N_(2) and CP-ZIF-8-900-N_(2),respectively.The effects of CP composition,pore structure and magnetic field intensity on OER(oxygen evolution reaction)were investigated.The results show that the in-situ loaded ZIF-8 forms a dense layer of rectangular dodecahedral particles on the fiber surface of CP,and forms a uniform nanoscale nitrogen-doped carbon material on the fiber surface after heat treatment.ZIF-8-900-N_(2) has a specific surface area of 1559 m^(2)/g,pore size of 0.57 nm and pore volume of 1.59 cm^(3)/g,which has the best magnetic properties and magneto-heating properties.CP-ZIF-8-900-N_(2) achieves a lowest OER overpotential of 334 mV(current density of 10 mA/cm^(2),iR-corrected)and Tafel slope of 187 mV/dec among carbon paper and nitrogen-doped porous carbon@CP materials.When the external magnetic field exists,the OER overpotential of the catalyst first decreases and then remains unchanged with the increase of magnetic field intensity.And CP-ZIF-8-900-N_(2) obtains the lowest overpotential of 316 mV(current density is 10 mA/cm^(2),non-iR-corrected)under a magnetic field intensity of 5.54×10^(−3) T,which is 20.4%lower than that without AC magnetic field.This is mainly due to the reduction of bubble size and the enhancement of bubble coalescence caused by the magneto hydrodynamic effect,which improves the desorption of bubbles from the electrode surface.

关 键 词：原位负载 Zn-MOF-74 ZIF-8 氮掺杂多孔碳 析氧反应 交流磁场 

分 类 号：TQ116.2[化学工程—无机化工]