本文主要研究内容
作者李纵(2019)在《g-C3N4基光催化剂的制备及催化性能研究》一文中研究指出:氢能是最具应用前景的清洁能源之一,利用太阳能光催化水分解制氢是制取氢气的绿色技术,当前研究核心在于开发高效、稳定的可见光光催化剂。作为非金属半导体光催化剂,氮化碳(g-C3N4)具有合适的能带结构、良好的可见光捕获能力和物理化学稳定性,具有一定的光催化产氢能力。但是它具有可见光吸收能力(λ<470 nm)不足、比表面积小、内部阻抗大、光生电子空穴容易复合等缺点,限制了其光催化制氢能力。为了克服以上的缺点,本文以g-C3N4半导体材料为基础,首先将银纳米粒子(Ag NPs)引入到g-C3N4中,通过控制Ag NPs在g-C3N4内的位置以提高g-C3N4的光催化性能。之后再引入助催化剂NiS有效促进载流子分离,增加反应活性位点,加速产氢动力学。最后,构建了Ag2Se/(Ag)/g-C3N4异质结,主要研究内容和结果如下:1)采用原位煅烧法将Ag NPs引入到g-C3N4中,通过调控Ag NPs在g-C3N4中的位置制备得到了Ag NPs插层g-C3N4和Ag NPs负载g-C3N4两种复合催化剂,光催化分解水制氢实验结果显示,Ag NPs插层对g-C3N4的光催化性能有显著的提高,1.0wt.%时,制氢速率为3.524 mmol·h-1·g-1,是纯g-C3N4的4.62倍。通过对其机理进行分析认为,Ag NPs插层在g-C3N4层内可以有效提高g-C3N4的载流子迁移速率,拓宽g-C3N4的可见光响应范围。2)采用水热法将NiS负载在Ag NPs插层g-C3N4二元复合材料的表面。XRD、FT-IR、XPS和TEM结果表明,通过原位煅烧和水热合成法可以成功地将Ag NPs和NiS均匀、稳定沉积在g-C3N4层内和表面,并且g-C3N4保持原有结构不变。紫外可见吸收光谱(UV-Vis)、瞬态光电流、阻抗(EIS)和光致发光谱(PL)分析表明,Ag NPs和NiS的引入不仅改善了体系的光吸收范围和强度,而且显著提高了体系光生电子和空穴的产生、分离性能,有助于提高光子利用效率。光催化分解水制氢实验发现,10 wt.%-NiS/1.0 wt.%-(Ag)/g-C3N4样品具有最优异的光催化分解水制氢性能,产氢速率可达9.728 mmol·g–1·h–1,是纯g-C3N4的10.82倍,二元10 wt.%-NiS/g-C3N4的3.45倍,1.0 wt.%-(Ag)/g-C3N4的2.77倍。稳定性实验表明10 wt.%-NiS/1.0wt.%-(Ag)/g-C3N4反应前后的XRD特征峰位置没有发生变化,循环四次后样品仍具有83%的催化活性,证明其具有良好的制氢稳定性。3)采用溶剂热回流法制备了Ag2Se/(Ag)/g-C3N4异质结光催化剂,Ag2Se作为一种高效的半导体光催化剂,通过与g-C3N4复合构成异质结,形成紧密的界面接触。为了使载流子在g-C3N4与Ag2Se两种半导体界面之间传输更快,在引入Ag2Se之前首先在g-C3N4中插入Ag NPs,以Ag NPs作为载流子传输通道,更有利于g-C3N4导带上的载流子向Ag2Se传递。光催化分解水制氢实验表明5 wt.%-Ag2Se/1.0wt.%-(Ag)/g-C3N4样品的光催化活性更高,为7.937 mmol·g–1·h–1,是g-C3N4的9.69倍。对样品进行循环实验表明,5 wt.%-Ag2Se/1.0 wt.%-(Ag)/g-C3N4样品在多次循环使用之后依然保持较高的活性。对光催化反应机理分析表明,在半导体/Ag NPs/半导体的异质结结构中,g-C3N4、Ag NPs和Ag2Se半导体三者之间的协同作用促进了载流子在不同半导体界面之间的传递,增强了复合材料光催化活性。
Abstract
qing neng shi zui ju ying yong qian jing de qing jie neng yuan zhi yi ,li yong tai yang neng guang cui hua shui fen jie zhi qing shi zhi qu qing qi de lu se ji shu ,dang qian yan jiu he xin zai yu kai fa gao xiao 、wen ding de ke jian guang guang cui hua ji 。zuo wei fei jin shu ban dao ti guang cui hua ji ,dan hua tan (g-C3N4)ju you ge kuo de neng dai jie gou 、liang hao de ke jian guang bu huo neng li he wu li hua xue wen ding xing ,ju you yi ding de guang cui hua chan qing neng li 。dan shi ta ju you ke jian guang xi shou neng li (λ<470 nm)bu zu 、bi biao mian ji xiao 、nei bu zu kang da 、guang sheng dian zi kong xue rong yi fu ge deng que dian ,xian zhi le ji guang cui hua zhi qing neng li 。wei le ke fu yi shang de que dian ,ben wen yi g-C3N4ban dao ti cai liao wei ji chu ,shou xian jiang yin na mi li zi (Ag NPs)yin ru dao g-C3N4zhong ,tong guo kong zhi Ag NPszai g-C3N4nei de wei zhi yi di gao g-C3N4de guang cui hua xing neng 。zhi hou zai yin ru zhu cui hua ji NiSyou xiao cu jin zai liu zi fen li ,zeng jia fan ying huo xing wei dian ,jia su chan qing dong li xue 。zui hou ,gou jian le Ag2Se/(Ag)/g-C3N4yi zhi jie ,zhu yao yan jiu nei rong he jie guo ru xia :1)cai yong yuan wei duan shao fa jiang Ag NPsyin ru dao g-C3N4zhong ,tong guo diao kong Ag NPszai g-C3N4zhong de wei zhi zhi bei de dao le Ag NPscha ceng g-C3N4he Ag NPsfu zai g-C3N4liang chong fu ge cui hua ji ,guang cui hua fen jie shui zhi qing shi yan jie guo xian shi ,Ag NPscha ceng dui g-C3N4de guang cui hua xing neng you xian zhe de di gao ,1.0wt.%shi ,zhi qing su lv wei 3.524 mmol·h-1·g-1,shi chun g-C3N4de 4.62bei 。tong guo dui ji ji li jin hang fen xi ren wei ,Ag NPscha ceng zai g-C3N4ceng nei ke yi you xiao di gao g-C3N4de zai liu zi qian yi su lv ,ta kuan g-C3N4de ke jian guang xiang ying fan wei 。2)cai yong shui re fa jiang NiSfu zai zai Ag NPscha ceng g-C3N4er yuan fu ge cai liao de biao mian 。XRD、FT-IR、XPShe TEMjie guo biao ming ,tong guo yuan wei duan shao he shui re ge cheng fa ke yi cheng gong de jiang Ag NPshe NiSjun yun 、wen ding chen ji zai g-C3N4ceng nei he biao mian ,bing ju g-C3N4bao chi yuan you jie gou bu bian 。zi wai ke jian xi shou guang pu (UV-Vis)、shun tai guang dian liu 、zu kang (EIS)he guang zhi fa guang pu (PL)fen xi biao ming ,Ag NPshe NiSde yin ru bu jin gai shan le ti ji de guang xi shou fan wei he jiang du ,er ju xian zhe di gao le ti ji guang sheng dian zi he kong xue de chan sheng 、fen li xing neng ,you zhu yu di gao guang zi li yong xiao lv 。guang cui hua fen jie shui zhi qing shi yan fa xian ,10 wt.%-NiS/1.0 wt.%-(Ag)/g-C3N4yang pin ju you zui you yi de guang cui hua fen jie shui zhi qing xing neng ,chan qing su lv ke da 9.728 mmol·g–1·h–1,shi chun g-C3N4de 10.82bei ,er yuan 10 wt.%-NiS/g-C3N4de 3.45bei ,1.0 wt.%-(Ag)/g-C3N4de 2.77bei 。wen ding xing shi yan biao ming 10 wt.%-NiS/1.0wt.%-(Ag)/g-C3N4fan ying qian hou de XRDte zheng feng wei zhi mei you fa sheng bian hua ,xun huan si ci hou yang pin reng ju you 83%de cui hua huo xing ,zheng ming ji ju you liang hao de zhi qing wen ding xing 。3)cai yong rong ji re hui liu fa zhi bei le Ag2Se/(Ag)/g-C3N4yi zhi jie guang cui hua ji ,Ag2Sezuo wei yi chong gao xiao de ban dao ti guang cui hua ji ,tong guo yu g-C3N4fu ge gou cheng yi zhi jie ,xing cheng jin mi de jie mian jie chu 。wei le shi zai liu zi zai g-C3N4yu Ag2Seliang chong ban dao ti jie mian zhi jian chuan shu geng kuai ,zai yin ru Ag2Sezhi qian shou xian zai g-C3N4zhong cha ru Ag NPs,yi Ag NPszuo wei zai liu zi chuan shu tong dao ,geng you li yu g-C3N4dao dai shang de zai liu zi xiang Ag2Sechuan di 。guang cui hua fen jie shui zhi qing shi yan biao ming 5 wt.%-Ag2Se/1.0wt.%-(Ag)/g-C3N4yang pin de guang cui hua huo xing geng gao ,wei 7.937 mmol·g–1·h–1,shi g-C3N4de 9.69bei 。dui yang pin jin hang xun huan shi yan biao ming ,5 wt.%-Ag2Se/1.0 wt.%-(Ag)/g-C3N4yang pin zai duo ci xun huan shi yong zhi hou yi ran bao chi jiao gao de huo xing 。dui guang cui hua fan ying ji li fen xi biao ming ,zai ban dao ti /Ag NPs/ban dao ti de yi zhi jie jie gou zhong ,g-C3N4、Ag NPshe Ag2Seban dao ti san zhe zhi jian de xie tong zuo yong cu jin le zai liu zi zai bu tong ban dao ti jie mian zhi jian de chuan di ,zeng jiang le fu ge cai liao guang cui hua huo xing 。
论文参考文献
论文详细介绍
论文作者分别是来自西北大学的李纵,发表于刊物西北大学2019-10-08论文,是一篇关于氮化碳论文,硫化镍论文,硒化银论文,光催化论文,西北大学2019-10-08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,资料来自西北大学2019-10-08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:氮化碳论文; 硫化镍论文; 硒化银论文; 光催化论文; 西北大学2019-10-08论文;