本文主要研究内容
作者李佳男（2019）在《尖晶石复合金属氧化物改性及其光催化性能研究》一文中研究指出：光催化(Photocatal ysis)是一种基于光能资源的绿色催化技术,能够有效利用太阳能实现污染物去除及资源化,且绿色无污染,在环境及能源领域有着广阔的应用前景。尖晶石金属氧化物半导体纳米材料以其稳定的结构、多变的性质、低廉的价格、绿色环保等特点,在光催化领域受到国内外研究人员的广泛关注。通过对尖晶石金属氧化物微观形貌及电子态结构的合理调控,深入探究其微纳性质与光催化活性之间的构效关系,对于光催化技术在环境污染控制领域的应用具有重要意义。因此,本论文从晶面调控、元素掺杂、微观形貌优化及多组分复合等方面对材料进行表/界面修饰改性,制备出具有不同功能性的尖晶石金属氧化物纳米材料,讨论了改性手段对其光催化性能的影响,并结合原位红外光谱分析技术及密度泛函理论计算等手段,研究了催化反应机理及内在活性增强机制。主要的研究发现如下:(1)通过水热法制备了一系列ZnFe2O4纳米颗粒,考察了不同晶面暴露对其可见光催化降解气相甲苯性能的影响。研究发现{001}和{111}晶面共同暴露的切角八面体ZnFe2O4纳米颗粒对气相甲苯表现出最佳的降解效果,甲苯降解率可达到65%:相对于单一{001}、{111}晶面暴露的ZnFe2O4纳米颗粒,在动力学反应速率方面分别提升了1.32倍和1.51倍。理论计算、光沉积和电子顺磁共振捕获自由基等实验结果表明ZnFe2O4光催化剂的{001}和{111}晶面之间能够形成表面晶面节,促进了光生载流子的迁移,协同{001}晶面催化转化特性,在反应中产生了丰富的·O2-和·OH物种,改善了材料的光催化降解性能。(2)采用原位掺杂溶剂热法制备了碳氮共掺杂的卵黄壳结构ZnFe2O4光催化剂,光谱表征和理论计算表明,碳氮元素的掺杂增强了材料对可见光的吸收、促进了反应中光生载流子的迁移并抑制了电子-空穴对的复合。以气相邻二氯苯为目标污染物,考察了不同碳氮源添加量和煅烧速率对光催化剂活性的影响,发现最佳条件下催化剂对气相气相邻二氯苯降解率能够达到60%。利用原位红外光谱技术揭示了气相邻二氯苯降解经历了亲核取代、氧化开环、转化成乙酸盐和甲酸盐等小分子及部分矿化成H2O和CO2等步骤,而电子顺磁共振自由基捕获实验表明了·O2-和·OH为反应过程中的活性物种。(3)采用分步水热法制备了碳点修饰的卵黄壳结构ZnFe2O4复合光催化剂,将碳点修饰于ZnFe2O4卵黄壳结构外表面,能够有效促进催化剂在可见光范围内的吸收,改善光生电子的迁移,减小电子-空穴对的复合机率。差分电荷密度理论计算结果表明碳点和ZnFe2O4界面之间存在着强烈的电荷相互作用,能够驱动光生电子从ZnFe2O4迁移至碳点,形成快速迁移路径。该催化剂在最佳光催化反应条件下,对气相邻二氯苯的降解率可达到74%。另外,采用原位红外光谱技术探究了降解过程中的瞬态物种变化及其迁移/转化路径。电子顺磁共振自由基捕获实验结果表明,·02-和.OH物种均参与到光催化降解反应过程中,且前者为主要的活性氧物种。(4)通过溶剂热法制备了具有2D纳米片/3D微米花分级结构的CuCo2O4尖晶石氧化物催化剂,采用高温加压原位拓扑转化的策略实现了硫元素由表面到内部的梯度掺杂,形成连续弯曲“反量子井”型能带结构,有效地加速了光生电子-空穴的分离和迁移过程。硫元素的掺杂并不会破坏原催化剂的2D/3D分级结构,低温电子顺磁共振结果表明,Grad-S-CuCo2O4样品中存在着氧空位缺陷态。在最佳光催化还原CO2反应条件下,Grad-S-CuCo2O4催化剂光催化还原产物CO的量可达181 μmol,其活性是未进行硫掺杂CuCo2O4催化剂的5.0倍,CO/H2选择性也提升了 1.95倍,并保持良好的稳定性/可循环性。(5)通过碳球软模板阳离子吸附-煅烧法制备了一系列CoMnOx空心纳米球尖晶石氧化物催化剂。理论计算发现Co掺杂能够加强MnO6单元的J-T畸变,促进电子的离域化过程,有利于提升材料的催化活性。将光催化技术和PMS活化高级氧化技术进行耦合,考察了不同的反应条件、催化剂样品对水中抗生素诺氟沙星降解性能的影响。实验结果表明,耦合体系对诺氟沙星的降解效率分别是单一光催化技术及过一硫酸氢钾活化技术的18.8倍和1.4倍。在最佳反应条件下,CoMnOx催化剂在耦合体系中对诺氟沙星降解率可达94%,且多次循环后依旧保持良好的催化稳定性。高效液相-质谱结果表明,诺氟沙星降解主要经历路径为哌嗪环转化、脱氟、去羧基反应及羟基化反应过程,淬灭实验和EPR结果证实了SO4·-是降解过程中的主要活性物种。
Abstract
guang cui hua (Photocatal ysis)shi yi chong ji yu guang neng zi yuan de lu se cui hua ji shu ,neng gou you xiao li yong tai yang neng shi xian wu ran wu qu chu ji zi yuan hua ,ju lu se mo wu ran ,zai huan jing ji neng yuan ling yu you zhao an kuo de ying yong qian jing 。jian jing dan jin shu yang hua wu ban dao ti na mi cai liao yi ji wen ding de jie gou 、duo bian de xing zhi 、di lian de jia ge 、lu se huan bao deng te dian ,zai guang cui hua ling yu shou dao guo nei wai yan jiu ren yuan de an fan guan zhu 。tong guo dui jian jing dan jin shu yang hua wu wei guan xing mao ji dian zi tai jie gou de ge li diao kong ,shen ru tan jiu ji wei na xing zhi yu guang cui hua huo xing zhi jian de gou xiao guan ji ,dui yu guang cui hua ji shu zai huan jing wu ran kong zhi ling yu de ying yong ju you chong yao yi yi 。yin ci ,ben lun wen cong jing mian diao kong 、yuan su can za 、wei guan xing mao you hua ji duo zu fen fu ge deng fang mian dui cai liao jin hang biao /jie mian xiu shi gai xing ,zhi bei chu ju you bu tong gong neng xing de jian jing dan jin shu yang hua wu na mi cai liao ,tao lun le gai xing shou duan dui ji guang cui hua xing neng de ying xiang ,bing jie ge yuan wei gong wai guang pu fen xi ji shu ji mi du fan han li lun ji suan deng shou duan ,yan jiu le cui hua fan ying ji li ji nei zai huo xing zeng jiang ji zhi 。zhu yao de yan jiu fa xian ru xia :(1)tong guo shui re fa zhi bei le yi ji lie ZnFe2O4na mi ke li ,kao cha le bu tong jing mian bao lou dui ji ke jian guang cui hua jiang jie qi xiang jia ben xing neng de ying xiang 。yan jiu fa xian {001}he {111}jing mian gong tong bao lou de qie jiao ba mian ti ZnFe2O4na mi ke li dui qi xiang jia ben biao xian chu zui jia de jiang jie xiao guo ,jia ben jiang jie lv ke da dao 65%:xiang dui yu chan yi {001}、{111}jing mian bao lou de ZnFe2O4na mi ke li ,zai dong li xue fan ying su lv fang mian fen bie di sheng le 1.32bei he 1.51bei 。li lun ji suan 、guang chen ji he dian zi shun ci gong zhen bu huo zi you ji deng shi yan jie guo biao ming ZnFe2O4guang cui hua ji de {001}he {111}jing mian zhi jian neng gou xing cheng biao mian jing mian jie ,cu jin le guang sheng zai liu zi de qian yi ,xie tong {001}jing mian cui hua zhuai hua te xing ,zai fan ying zhong chan sheng le feng fu de ·O2-he ·OHwu chong ,gai shan le cai liao de guang cui hua jiang jie xing neng 。(2)cai yong yuan wei can za rong ji re fa zhi bei le tan dan gong can za de luan huang ke jie gou ZnFe2O4guang cui hua ji ,guang pu biao zheng he li lun ji suan biao ming ,tan dan yuan su de can za zeng jiang le cai liao dui ke jian guang de xi shou 、cu jin le fan ying zhong guang sheng zai liu zi de qian yi bing yi zhi le dian zi -kong xue dui de fu ge 。yi qi xiang lin er lv ben wei mu biao wu ran wu ,kao cha le bu tong tan dan yuan tian jia liang he duan shao su lv dui guang cui hua ji huo xing de ying xiang ,fa xian zui jia tiao jian xia cui hua ji dui qi xiang qi xiang lin er lv ben jiang jie lv neng gou da dao 60%。li yong yuan wei gong wai guang pu ji shu jie shi le qi xiang lin er lv ben jiang jie jing li le qin he qu dai 、yang hua kai huan 、zhuai hua cheng yi suan yan he jia suan yan deng xiao fen zi ji bu fen kuang hua cheng H2Ohe CO2deng bu zhou ,er dian zi shun ci gong zhen zi you ji bu huo shi yan biao ming le ·O2-he ·OHwei fan ying guo cheng zhong de huo xing wu chong 。(3)cai yong fen bu shui re fa zhi bei le tan dian xiu shi de luan huang ke jie gou ZnFe2O4fu ge guang cui hua ji ,jiang tan dian xiu shi yu ZnFe2O4luan huang ke jie gou wai biao mian ,neng gou you xiao cu jin cui hua ji zai ke jian guang fan wei nei de xi shou ,gai shan guang sheng dian zi de qian yi ,jian xiao dian zi -kong xue dui de fu ge ji lv 。cha fen dian he mi du li lun ji suan jie guo biao ming tan dian he ZnFe2O4jie mian zhi jian cun zai zhao jiang lie de dian he xiang hu zuo yong ,neng gou qu dong guang sheng dian zi cong ZnFe2O4qian yi zhi tan dian ,xing cheng kuai su qian yi lu jing 。gai cui hua ji zai zui jia guang cui hua fan ying tiao jian xia ,dui qi xiang lin er lv ben de jiang jie lv ke da dao 74%。ling wai ,cai yong yuan wei gong wai guang pu ji shu tan jiu le jiang jie guo cheng zhong de shun tai wu chong bian hua ji ji qian yi /zhuai hua lu jing 。dian zi shun ci gong zhen zi you ji bu huo shi yan jie guo biao ming ,·02-he .OHwu chong jun can yu dao guang cui hua jiang jie fan ying guo cheng zhong ,ju qian zhe wei zhu yao de huo xing yang wu chong 。(4)tong guo rong ji re fa zhi bei le ju you 2Dna mi pian /3Dwei mi hua fen ji jie gou de CuCo2O4jian jing dan yang hua wu cui hua ji ,cai yong gao wen jia ya yuan wei ta pu zhuai hua de ce lve shi xian le liu yuan su you biao mian dao nei bu de ti du can za ,xing cheng lian xu wan qu “fan liang zi jing ”xing neng dai jie gou ,you xiao de jia su le guang sheng dian zi -kong xue de fen li he qian yi guo cheng 。liu yuan su de can za bing bu hui po huai yuan cui hua ji de 2D/3Dfen ji jie gou ,di wen dian zi shun ci gong zhen jie guo biao ming ,Grad-S-CuCo2O4yang pin zhong cun zai zhao yang kong wei que xian tai 。zai zui jia guang cui hua hai yuan CO2fan ying tiao jian xia ,Grad-S-CuCo2O4cui hua ji guang cui hua hai yuan chan wu COde liang ke da 181 μmol,ji huo xing shi wei jin hang liu can za CuCo2O4cui hua ji de 5.0bei ,CO/H2shua ze xing ye di sheng le 1.95bei ,bing bao chi liang hao de wen ding xing /ke xun huan xing 。(5)tong guo tan qiu ruan mo ban yang li zi xi fu -duan shao fa zhi bei le yi ji lie CoMnOxkong xin na mi qiu jian jing dan yang hua wu cui hua ji 。li lun ji suan fa xian Cocan za neng gou jia jiang MnO6chan yuan de J-Tji bian ,cu jin dian zi de li yu hua guo cheng ,you li yu di sheng cai liao de cui hua huo xing 。jiang guang cui hua ji shu he PMShuo hua gao ji yang hua ji shu jin hang ou ge ,kao cha le bu tong de fan ying tiao jian 、cui hua ji yang pin dui shui zhong kang sheng su nuo fu sha xing jiang jie xing neng de ying xiang 。shi yan jie guo biao ming ,ou ge ti ji dui nuo fu sha xing de jiang jie xiao lv fen bie shi chan yi guang cui hua ji shu ji guo yi liu suan qing jia huo hua ji shu de 18.8bei he 1.4bei 。zai zui jia fan ying tiao jian xia ,CoMnOxcui hua ji zai ou ge ti ji zhong dui nuo fu sha xing jiang jie lv ke da 94%,ju duo ci xun huan hou yi jiu bao chi liang hao de cui hua wen ding xing 。gao xiao ye xiang -zhi pu jie guo biao ming ,nuo fu sha xing jiang jie zhu yao jing li lu jing wei pai qin huan zhuai hua 、tuo fu 、qu suo ji fan ying ji qiang ji hua fan ying guo cheng ,cui mie shi yan he EPRjie guo zheng shi le SO4·-shi jiang jie guo cheng zhong de zhu yao huo xing wu chong 。
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论文详细介绍
论文作者分别是来自大连理工大学的李佳男，发表于刊物大连理工大学2019-07-19论文，是一篇关于尖晶石金属氧化物论文,光催化论文,降解论文,还原论文,多技术耦合论文,大连理工大学2019-07-19论文的文章。本文可供学术参考使用，各位学者可以免费参考阅读下载，文章观点不代表本站观点，资料来自大连理工大学2019-07-19论文网站，若本站收录的文献无意侵犯了您的著作版权，请联系我们删除。
标签：尖晶石金属氧化物论文; 光催化论文; 降解论文; 还原论文; 多技术耦合论文; 大连理工大学2019-07-19论文;