CoFe-LDH/泡沫铜的制备及催化介质阻挡放电等离子体降解水中敌草隆性能与机制  

Preparation of CoFe-LDH/Copper Foam and Its Catalytic Performance and Mechanism of Diuron Degradation by Dielectric Barrier Discharge Plasma in Water

作　　者：沈天瑶 杨怿 于海鹤 徐鹏 张广山 王鹏 SHEN Tian-Yao;YANG Yi;YU Hai-He;XU Peng;ZHANG Guang-Shan;WANG Peng(School of Environment,Harbin Institute of Technology,Harbin 150090,China;College of Resource and Environment,Qingdao Agricultural University,Qingdao 266109,China)

机构地区：[1]哈尔滨工业大学环境学院,哈尔滨150090 [2]青岛农业大学资源与环境学院,青岛266109

出　　处：《应用化学》2024年第2期243-255,共13页Chinese Journal of Applied Chemistry

基　　金：国家自然科学基金(No.52370174);山东省自然科学基金(No.ZR2022ME128)资助。

摘　　要：采用一步水热法,以钴和铁元素为活性组分制备了片层状钴铁层状双金属氢氧化物(CoFe-LDH),通过调节元素摩尔比和水热温度、时间以及尿素投加量的制备条件得到了可以高效催化介质阻挡放电等离子体(DBDP)的粉末催化剂。研究结果表明,当n(尿素)∶n(Co)∶n(Fe)=10∶3∶1,水热温度为120℃,水热时间18 h时,得到的CoFe-LDH催化性能最优,其催化DBDP降解敌草隆(DUR)的降解率和降解速率常数分别达到了96.54%和0.1354 min^(-1),制备条件中水热时间对催化性能影响最大。在此基础上,将配比优化的CoFe-LDH负载在泡沫铜(CuF)表面,得到了片状可回收的三元CoFe-LDH/CuF(CFHC)催化剂。系统地表征了CFHC的结构组成,研究了微观结构和元素组成与催化性能之间的内在联系。由于还原态铜元素的引入,增加了催化剂表面的氧空位含量,显著地提升了复合材料的催化性能。CFHC的加入成功将DBDP对敌草隆的去除速率提升至0.2175 min^(-1),是DBDP空白体系的3.18倍。CuF的引入增加了催化剂的导电能力,在降解过程中钴、铁、铜和氧空位之间的电子转移是高催化活性的根本原因,CFHC重新调整了DBDP体系内的优势活性物种,·O_(2)^(-)和^(1)O_(2)取代·OH成为了降解敌草隆的主要活性物质。The layered cobalt-iron layered bimetallic hydroxide(CoFe-LDH)was prepared by hydrothermal method with cobalt and iron as the active sites.The optimized powder catalyst is obtained with the element ratio n(Co)∶n(Fe)=3∶1 at 120℃18 h,and the hydrothermal time significantly affects the catalytic performance.Insufficient hydrothermal time,temperature or urea dosage is unconducive to crystal growth.However,excessive increase of reaction conditions will change the crystal shape and make the lamella thicker.Furthermore,the optimized CoFe-LDH is loaded on the copper foam(CuF)surface,obtaining the recyclable terpolymer CoFe-LDH/CuF(CFHC)sheet catalyst.Due to reduced Cu elements'participation,the molar percentage of oxygen vacancy on the catalyst surface is increased by 45.90%.The catalysis performance of CFHC is evaluated by characterizing the diuron(DUR)elimination efficiency,a harmful phenyl urea group herbicide,in the DBDP system,and the DUR degradation rate in the DBDP/CFHC system is 3.18 times as high as that in the DBDP system.The structure and composition of CFHC are characterized systematically,and the intrinsic relationship between the microstructure,elemental composition,and catalytic performance is studied.The introduction of CuF increases the conductivity of the catalyst and the reducible copper increases the oxygen vacancy molar percentage content.Thus,the fundamental reason for the high catalytic activity is the electron transfer in cobalt,iron,copper,and oxygen vacancy in the degradation process.CFHC re-adjusts the dominant active species in the DBDP system.·O_(2)^(-)and^(1)O_(2)replaced·OH as the main active substances for the degradation of DUR.The work would positively affect the DBDP catalysis development,the functional structure design,and the selection of active species.

关 键 词：层状双金属氢氧化物 介质阻挡放电等离子体 钴铁 敌草隆 泡沫铜 

分 类 号：O643.3[理学—物理化学]