本文主要研究内容
作者刘胜伟（2019）在《阴离子表面修饰TiO2的可能作用机理及光催化活性评价》一文中研究指出：半导体光催化已经有40多年的研究历史,因其可利用清洁、可再生的太阳能降解有机污染物、产H2等,并且不会造成二次污染,有望成为解决环境污染和能源再生问题的新技术。在众多半导体光催化剂中,TiO2是研究得最多的,因为它具有高效、稳定、无毒等优点。为了进一步提高TiO2的光催化性能,人们采用了诸如贵金属、无机阴离子表面修饰等方法,但是关于无机阴离子的影响一直存在较大的争议。此外,光催化活性评价对于半导体光催化研究也具有重大的意义。为此,我们从表面吸附的角度定量研究了氟离子和磷酸根对锐钛矿TiO2光催化降解苯酚的影响,并综合考察了吸附量和溶液吸光度对Cr(Ⅵ)离子光催化还原起.始反应速率的影响。论文具体内容分为以下两个部分:第一部分,我们首先采用溶胶-凝胶法合成了不含杂质离子的锐钛矿TiO2,然后以光化学沉积法在其表面负载了Pt,所得样品使用XRD、XPS、拉曼光谱等多种手段进行了表征。以上述所得样品为光催化剂,我们研究了氟离子和磷酸根对苯酚光催化降解的影响,发现在pH 5.2的悬浮液中,加入0.1-30 mM阴离子,苯酚的光催化降解速率常数都得到了增大,并且氟离子的提高倍数大于磷酸根。我们又结合Langmuir单层吸附模型测定了阴离子在固体表面的吸附量,结果表明氟离子的吸附量小于磷酸根,更有趣的是,反应速率提高倍数与阴离子的吸附量呈线性关系,其中,氟离子的斜率大约为磷酸根的2.7倍。这些现象表明阴离子的正效应来自于吸附在固体表面的阴离子,并且氟离子的活性大于磷酸根。光电化学实验表明,氟离子和磷酸根都有助于光生空穴氧化苯酚,但是分别抑制和促进水氧化。此外,Mott-Schottky曲线表明氟离子和磷酸根分别使平带电位负移159 mV和正移89 mV,前者有利于TiO2价带与苯酚发生轨道重叠,后者有利于TiO2导带与O2发生轨道重叠,进而加快界面电荷转移。但是氟离子负移的值大于磷酸根正移的值,因此,氟离子具有更大的正效应第二部分,我们对Cr(Ⅵ)离子光催化还原用于光催化活性评价进行了初步研究。Cr(Ⅵ)离子的浓度用比色法测定。在pH 3.5条件下,测定了Cr(Ⅵ)离子在锐钛矿TiO2表面的吸附等温线,结果表明,Cr(Ⅵ)离子在锐钛矿TiO2表面是多层吸附,但是,其单层吸附区仍然符合Langmuir吸附模型。以λ>320 nm的紫外光为光源,在pH 3.5条件下,我们考察了离子吸附量对Cr(Ⅵ)离子光催化降解的起始反应速率的影响,发现起始反应速率随吸附量的增大而减小,但是,综合考虑溶液吸光度的影响后,随着吸附量的增大,修正后的起始反应速率先增大后减小。我们认为,离子浓度增大一方面带来吸附的正效应,另一方面也带来了溶液吸光的负效应,当吸附的正效应大于吸光的负效应时,起始反应速率增大,当吸附量趋近饱和值后,离子浓度的增大不再带来吸附的正效应,而溶液吸光的负效应继续增大,因此起始反应速率开始减小。
Abstract
ban dao ti guang cui hua yi jing you 40duo nian de yan jiu li shi ,yin ji ke li yong qing jie 、ke zai sheng de tai yang neng jiang jie you ji wu ran wu 、chan H2deng ,bing ju bu hui zao cheng er ci wu ran ,you wang cheng wei jie jue huan jing wu ran he neng yuan zai sheng wen ti de xin ji shu 。zai zhong duo ban dao ti guang cui hua ji zhong ,TiO2shi yan jiu de zui duo de ,yin wei ta ju you gao xiao 、wen ding 、mo du deng you dian 。wei le jin yi bu di gao TiO2de guang cui hua xing neng ,ren men cai yong le zhu ru gui jin shu 、mo ji yin li zi biao mian xiu shi deng fang fa ,dan shi guan yu mo ji yin li zi de ying xiang yi zhi cun zai jiao da de zheng yi 。ci wai ,guang cui hua huo xing ping jia dui yu ban dao ti guang cui hua yan jiu ye ju you chong da de yi yi 。wei ci ,wo men cong biao mian xi fu de jiao du ding liang yan jiu le fu li zi he lin suan gen dui rui tai kuang TiO2guang cui hua jiang jie ben fen de ying xiang ,bing zeng ge kao cha le xi fu liang he rong ye xi guang du dui Cr(Ⅵ)li zi guang cui hua hai yuan qi .shi fan ying su lv de ying xiang 。lun wen ju ti nei rong fen wei yi xia liang ge bu fen :di yi bu fen ,wo men shou xian cai yong rong jiao -ning jiao fa ge cheng le bu han za zhi li zi de rui tai kuang TiO2,ran hou yi guang hua xue chen ji fa zai ji biao mian fu zai le Pt,suo de yang pin shi yong XRD、XPS、la man guang pu deng duo chong shou duan jin hang le biao zheng 。yi shang shu suo de yang pin wei guang cui hua ji ,wo men yan jiu le fu li zi he lin suan gen dui ben fen guang cui hua jiang jie de ying xiang ,fa xian zai pH 5.2de xuan fu ye zhong ,jia ru 0.1-30 mMyin li zi ,ben fen de guang cui hua jiang jie su lv chang shu dou de dao le zeng da ,bing ju fu li zi de di gao bei shu da yu lin suan gen 。wo men you jie ge Langmuirchan ceng xi fu mo xing ce ding le yin li zi zai gu ti biao mian de xi fu liang ,jie guo biao ming fu li zi de xi fu liang xiao yu lin suan gen ,geng you qu de shi ,fan ying su lv di gao bei shu yu yin li zi de xi fu liang cheng xian xing guan ji ,ji zhong ,fu li zi de xie lv da yao wei lin suan gen de 2.7bei 。zhe xie xian xiang biao ming yin li zi de zheng xiao ying lai zi yu xi fu zai gu ti biao mian de yin li zi ,bing ju fu li zi de huo xing da yu lin suan gen 。guang dian hua xue shi yan biao ming ,fu li zi he lin suan gen dou you zhu yu guang sheng kong xue yang hua ben fen ,dan shi fen bie yi zhi he cu jin shui yang hua 。ci wai ,Mott-Schottkyqu xian biao ming fu li zi he lin suan gen fen bie shi ping dai dian wei fu yi 159 mVhe zheng yi 89 mV,qian zhe you li yu TiO2jia dai yu ben fen fa sheng gui dao chong die ,hou zhe you li yu TiO2dao dai yu O2fa sheng gui dao chong die ,jin er jia kuai jie mian dian he zhuai yi 。dan shi fu li zi fu yi de zhi da yu lin suan gen zheng yi de zhi ,yin ci ,fu li zi ju you geng da de zheng xiao ying di er bu fen ,wo men dui Cr(Ⅵ)li zi guang cui hua hai yuan yong yu guang cui hua huo xing ping jia jin hang le chu bu yan jiu 。Cr(Ⅵ)li zi de nong du yong bi se fa ce ding 。zai pH 3.5tiao jian xia ,ce ding le Cr(Ⅵ)li zi zai rui tai kuang TiO2biao mian de xi fu deng wen xian ,jie guo biao ming ,Cr(Ⅵ)li zi zai rui tai kuang TiO2biao mian shi duo ceng xi fu ,dan shi ,ji chan ceng xi fu ou reng ran fu ge Langmuirxi fu mo xing 。yi λ>320 nmde zi wai guang wei guang yuan ,zai pH 3.5tiao jian xia ,wo men kao cha le li zi xi fu liang dui Cr(Ⅵ)li zi guang cui hua jiang jie de qi shi fan ying su lv de ying xiang ,fa xian qi shi fan ying su lv sui xi fu liang de zeng da er jian xiao ,dan shi ,zeng ge kao lv rong ye xi guang du de ying xiang hou ,sui zhao xi fu liang de zeng da ,xiu zheng hou de qi shi fan ying su lv xian zeng da hou jian xiao 。wo men ren wei ,li zi nong du zeng da yi fang mian dai lai xi fu de zheng xiao ying ,ling yi fang mian ye dai lai le rong ye xi guang de fu xiao ying ,dang xi fu de zheng xiao ying da yu xi guang de fu xiao ying shi ,qi shi fan ying su lv zeng da ,dang xi fu liang qu jin bao he zhi hou ,li zi nong du de zeng da bu zai dai lai xi fu de zheng xiao ying ,er rong ye xi guang de fu xiao ying ji xu zeng da ,yin ci qi shi fan ying su lv kai shi jian xiao 。
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论文作者分别是来自浙江大学的刘胜伟，发表于刊物浙江大学2019-07-17论文，是一篇关于光电催化论文,锐钛矿论文,氟离子论文,磷酸根论文,吸附论文,离子论文,吸光度论文,浙江大学2019-07-17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，资料来自浙江大学2019-07-17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：光电催化论文; 锐钛矿论文; 氟离子论文; 磷酸根论文; 吸附论文; 离子论文; 吸光度论文; 浙江大学2019-07-17论文;