多壁碳纳米管负载镧掺杂氢氧化铁纳米胶粒修饰碳纤维簇电极对CO_2的光电催化还原研究  

The Photoelectric Catalytic Reduction Behavior of Multi-walled Carbon Nanotubes Supported Colloidal Ferric Hydroxide Nanoparticles and Lanthanum Doping Which Modified Carbon Fiber Clusters Electrode with CO_2

作　　者：那宝双 朱永春[1,2] 辛士刚[1] 

机构地区：[1]沈阳师范大学化学化工学院,沈阳110034 [2]沈阳师范大学能源与环境催化研究所,沈阳110034

出　　处：《科学技术与工程》2017年第7期10-19,共10页Science Technology and Engineering

基　　金：国家科技部国际合作重大项目(2004DFA02700);国家自然科学基金(20875063);辽宁教育厅项目(2004-c022);国家电分析重点实验室项目(2006-06);沈阳市科技局基金(2007-GX-32)资助

摘　　要：通过溶胶法制备了氢氧化铁溶胶纳米粒子及镧掺杂氢氧化铁溶胶纳米粒子,多壁碳纳米管负载后,化学修饰在碳纤维簇电极上,制备出多壁碳纳米管负载镧掺杂氢氧化铁纳米胶粒修饰碳纤维簇电极,该电极对CO_2有光电催化还原作用。多壁碳纳米管修饰后增加了电极的表面积,氢氧化铁纳米胶粒修饰后还原电流变大增强了电催化还原功能,镧掺杂后起始电位正移增加了光催化还原功能。以MOPAC2012提供的PM7半经验分子轨道方法在设计的铁-氧-氯构成的氢氧化铁分子簇模型上进行半经验分子轨道计算,通过对计算结果的热力学,能级,分子轨道组成以及光谱分析表明,氢氧化铁溶胶纳米粒子及其镧掺杂对CO_2有光电催化还原行为。所设计的分子簇模型是具有热力学稳定的结构,镧掺杂加强了其稳定性。氢氧化铁分子簇具有较好的电子转移性,镧掺杂降低了其费米能级高度,有利于光催化,与实验结果相对应。且催化后的CO_2在键长、分子结构以及红外光谱都发生了较大变化,并具有碳酸的前体结构,实现了对CO_2分子的活化和光电化学催化还原。The multi-walled carbon nanotubes supported colloidal ferric hydroxide nanoparticles and lanthanum doping which modified carbon fiber clusters electrode has photoelectric catalytic effect on CO2,the colloidal ferric hydroxide nanoparticles and La-doped colloidal ferric hydroxide nanoparticles were prepared by sol-gel method,after the multi-walled carbon nanotubes were loaded,the chemical modification was carried on the carbon fiber cluster electrode.The surface area of the carbon fiber cluster electrodes was increased after themodification of multiwalled carbon nanotubes,the reduction current becomes large after the modification of colloidal ferric hydroxide nanoparticles,it enhance electrochemical catalytic function.The initial potential becomes more positive after lanthanum doping,it increases the photocatalytic activity.The photoelectrochemical properties of CO2 by amorphous ferric oxideand lanthanum doped was studied by PM7 program from MOPAC2012 semi-empirical quantum chemistry methods based on molecular cluster models of ferric hydroxide composed of Fe-O-Cl,lanthanum and CO2.According to the results of analysis base on thermodynamics,energy level,molecular orbital composition and spectroscopic analysis showed that colloidal ferric hydroxide nanoparticles and lanthanum doping have photoelectric catalytic reduction behavior for CO2.The results show that the molecular cluster models are all thermodynamically stable.The ferric hydroxide clusters doped by lanthanum further increase their stability.Ferric hydroxide clusters have better electron transfer properties.Lanthanum doping reduces their Fermi level,which are helpful to improve their photocatalytic properties.Large changes in the bond length,molecular structure and infrared spectrum of the CO2 before and after catalysis and makes CO2 as a precursor structure of caronic acid,which realizes the activation and catalysis of CO2 molecules in the progress.

关 键 词：多壁碳纳米管 氢氧化铁溶胶纳米粒子 镧掺杂 光电催化 二氧化碳 PM7半经验分子轨道法 

分 类 号：O643.36[理学—物理化学]