本文主要研究内容
作者赵静黎(2019)在《石墨相氮化碳点/石墨相氮化碳纳米片/石墨烯三元复合材料的制备及其光催化分解水析氢性能研究》一文中研究指出:氢气作为燃料时,因为具有燃烧产物无污染、燃烧能量高、可以储存备用等优点,所以有望成为主要的清洁能源之一。而在各种产生氢气的方法中,光催化水分解技术作为实现太阳能转化成氢能的一种途径,具有广阔的应用前景。自光催化技术发展以来,科研者们开发了许多用于光催化水分解的半导体光催化剂。然而,这些光催化剂由于其带隙较宽、只能吸收紫外线,量子效率低,稳定性差,制备困难,材料昂贵等因素限制了实际应用。石墨相氮化碳(g-C3N4)因其绿色环保,合成成本低,易与其它半导体紧密结合等优点,广泛应用于光催化水分解析氢中。然而,由于块状g-C3N4的比表面积小、可见光利用率低、光生电子空穴极易复合、反应活性位点少、表面反应动力学缓慢、以及电荷迁移率低等缺点,导致其光催化析氢活性并不理想。目前,用于提升g-C3N4的光催化性能的策略可以分为三大类,包括纳米碳负载、异质结构建和维度调控。其中,纳米碳材料负载可以与g-C3N4之间形成碳基肖特基结,促进电荷迁移;异质结构建可以诱导带弯曲和内部电场形成,促进电荷转移;维度调控则可以缩短电子到表面进行氧化还原反应的迁移路径,促进电荷分离。本论文中,我们通过煅烧三聚氰胺得到g-C3N4,然后对g-C3N4进行酸处理使其表面电荷由负转正,在静电作用力下带正电的g-C3N4与带负电的氧化石墨烯(GO)自组装进而形成质子化g-C3N4/rGO二元复合材料。在此基础之上,我们通过水热法将硼掺杂的g-C3N4点(BCNDs)负载到质子化g-C3N4/rGO的表面,形成三元非金属异质结(质子化g-C3N4/rGO/BCNDs)。此外,为了缩短电子参与光反应的迁移路径,进一步提高光催化活性,我们将非金属异质结中的块体g-C3N4替换成热氧化剥离后的、比表面积较大的g-C3N4,形成三元异质结复合材料(CNNS/rGO/BCNDs)。其主要实验内容和结论如下:(1)针对块状g-C3N4的电荷迁移率低的问题,我们在静电作用和水热作用下得到质子化g-C3N4/rGO二元复合材料。两种材料之间通过形成肖特基结提高电荷的迁移率。通过TEM、Zeta电位、XPS、XRD、FT-IR、BET等多种表征手段来分析复合材料的形貌、组成等;通过光催化活性在线分析系统研究复合材料在可见光下水分解析氢的光催化活性。结果表明,质子化g-C3N4/rGO的光催化析氢活性可达到307.7μmol·g-1·h-1,是g-C3N4(69.7μmol·g-1·h-1)的4.5倍,是质子化g-C3N4(12.2μmol·g-1·h-1)的25.2倍。其中,rGO作为电子传输桥促进质子化g-C3N4/rGO中的电荷分离,有效提高其光催化析氢活性。(2)针对块状g-C3N4的光生电子空穴极易复合的问题,我们将BCNDs负载到质子化g-C3N4/rGO表面,形成非金属异质结促进电荷转移。通过上述多种表征手段对质子化g-C3N4/rGO/BCNDs进行相关表征。结果表明,引入BCNDs后,其光催化析氢活性可达到741.4μmol·g-1·h-1,是质子化g-C3N4/0.1 wt%rGO(307.7μmol·g-1·h-1)的2.4倍,是质子化g-C3N4/(7 mL)BCNDs(320.0μmol·g-1·h-1)的2.3倍。在三元异质结中,可以结合石墨烯和BCNDs的优势,触发协同效应,改善光催化析氢活性。(3)针对块状g-C3N4的比表面积小的问题,我们通过热氧化法得到g-C3N4纳米片(CNNS),然后再与石墨烯、BCNDs复合,得到CNNS/rGO/BCNDs三元复合材料,更进一步提升其光催化析氢活性。通过上述多种表征手段对CNNS/rGO/BCNDs进行相关表征。结果表明,其光催化析氢活性可达到2036.1μmol·g-1·h-1,是CNNS(176.9μmol·g-1·h-1)的11.5倍,是CNNS/0.2 wt%rGO(270.1μmol·g-1·h-1)的7.5倍,是CNNS/(12 mL)BCNDs(1145.5μmol·g-1·h-1)的1.7倍。热氧化剥离后的g-C3N4(166.3 m2·g-1)的比表面积相对于块状g-C3N4(20.4 m2·g-1)提高了8.2倍。CNNS的比表面积增大后,可以显著缩短电荷迁移路径,抑制电荷重组,更进一步提升光催化析氢活性。
Abstract
qing qi zuo wei ran liao shi ,yin wei ju you ran shao chan wu mo wu ran 、ran shao neng liang gao 、ke yi chu cun bei yong deng you dian ,suo yi you wang cheng wei zhu yao de qing jie neng yuan zhi yi 。er zai ge chong chan sheng qing qi de fang fa zhong ,guang cui hua shui fen jie ji shu zuo wei shi xian tai yang neng zhuai hua cheng qing neng de yi chong tu jing ,ju you an kuo de ying yong qian jing 。zi guang cui hua ji shu fa zhan yi lai ,ke yan zhe men kai fa le hu duo yong yu guang cui hua shui fen jie de ban dao ti guang cui hua ji 。ran er ,zhe xie guang cui hua ji you yu ji dai xi jiao kuan 、zhi neng xi shou zi wai xian ,liang zi xiao lv di ,wen ding xing cha ,zhi bei kun nan ,cai liao ang gui deng yin su xian zhi le shi ji ying yong 。dan mo xiang dan hua tan (g-C3N4)yin ji lu se huan bao ,ge cheng cheng ben di ,yi yu ji ta ban dao ti jin mi jie ge deng you dian ,an fan ying yong yu guang cui hua shui fen jie xi qing zhong 。ran er ,you yu kuai zhuang g-C3N4de bi biao mian ji xiao 、ke jian guang li yong lv di 、guang sheng dian zi kong xue ji yi fu ge 、fan ying huo xing wei dian shao 、biao mian fan ying dong li xue huan man 、yi ji dian he qian yi lv di deng que dian ,dao zhi ji guang cui hua xi qing huo xing bing bu li xiang 。mu qian ,yong yu di sheng g-C3N4de guang cui hua xing neng de ce lve ke yi fen wei san da lei ,bao gua na mi tan fu zai 、yi zhi jie gou jian he wei du diao kong 。ji zhong ,na mi tan cai liao fu zai ke yi yu g-C3N4zhi jian xing cheng tan ji xiao te ji jie ,cu jin dian he qian yi ;yi zhi jie gou jian ke yi you dao dai wan qu he nei bu dian chang xing cheng ,cu jin dian he zhuai yi ;wei du diao kong ze ke yi su duan dian zi dao biao mian jin hang yang hua hai yuan fan ying de qian yi lu jing ,cu jin dian he fen li 。ben lun wen zhong ,wo men tong guo duan shao san ju qing an de dao g-C3N4,ran hou dui g-C3N4jin hang suan chu li shi ji biao mian dian he you fu zhuai zheng ,zai jing dian zuo yong li xia dai zheng dian de g-C3N4yu dai fu dian de yang hua dan mo xi (GO)zi zu zhuang jin er xing cheng zhi zi hua g-C3N4/rGOer yuan fu ge cai liao 。zai ci ji chu zhi shang ,wo men tong guo shui re fa jiang peng can za de g-C3N4dian (BCNDs)fu zai dao zhi zi hua g-C3N4/rGOde biao mian ,xing cheng san yuan fei jin shu yi zhi jie (zhi zi hua g-C3N4/rGO/BCNDs)。ci wai ,wei le su duan dian zi can yu guang fan ying de qian yi lu jing ,jin yi bu di gao guang cui hua huo xing ,wo men jiang fei jin shu yi zhi jie zhong de kuai ti g-C3N4ti huan cheng re yang hua bao li hou de 、bi biao mian ji jiao da de g-C3N4,xing cheng san yuan yi zhi jie fu ge cai liao (CNNS/rGO/BCNDs)。ji zhu yao shi yan nei rong he jie lun ru xia :(1)zhen dui kuai zhuang g-C3N4de dian he qian yi lv di de wen ti ,wo men zai jing dian zuo yong he shui re zuo yong xia de dao zhi zi hua g-C3N4/rGOer yuan fu ge cai liao 。liang chong cai liao zhi jian tong guo xing cheng xiao te ji jie di gao dian he de qian yi lv 。tong guo TEM、Zetadian wei 、XPS、XRD、FT-IR、BETdeng duo chong biao zheng shou duan lai fen xi fu ge cai liao de xing mao 、zu cheng deng ;tong guo guang cui hua huo xing zai xian fen xi ji tong yan jiu fu ge cai liao zai ke jian guang xia shui fen jie xi qing de guang cui hua huo xing 。jie guo biao ming ,zhi zi hua g-C3N4/rGOde guang cui hua xi qing huo xing ke da dao 307.7μmol·g-1·h-1,shi g-C3N4(69.7μmol·g-1·h-1)de 4.5bei ,shi zhi zi hua g-C3N4(12.2μmol·g-1·h-1)de 25.2bei 。ji zhong ,rGOzuo wei dian zi chuan shu qiao cu jin zhi zi hua g-C3N4/rGOzhong de dian he fen li ,you xiao di gao ji guang cui hua xi qing huo xing 。(2)zhen dui kuai zhuang g-C3N4de guang sheng dian zi kong xue ji yi fu ge de wen ti ,wo men jiang BCNDsfu zai dao zhi zi hua g-C3N4/rGObiao mian ,xing cheng fei jin shu yi zhi jie cu jin dian he zhuai yi 。tong guo shang shu duo chong biao zheng shou duan dui zhi zi hua g-C3N4/rGO/BCNDsjin hang xiang guan biao zheng 。jie guo biao ming ,yin ru BCNDshou ,ji guang cui hua xi qing huo xing ke da dao 741.4μmol·g-1·h-1,shi zhi zi hua g-C3N4/0.1 wt%rGO(307.7μmol·g-1·h-1)de 2.4bei ,shi zhi zi hua g-C3N4/(7 mL)BCNDs(320.0μmol·g-1·h-1)de 2.3bei 。zai san yuan yi zhi jie zhong ,ke yi jie ge dan mo xi he BCNDsde you shi ,chu fa xie tong xiao ying ,gai shan guang cui hua xi qing huo xing 。(3)zhen dui kuai zhuang g-C3N4de bi biao mian ji xiao de wen ti ,wo men tong guo re yang hua fa de dao g-C3N4na mi pian (CNNS),ran hou zai yu dan mo xi 、BCNDsfu ge ,de dao CNNS/rGO/BCNDssan yuan fu ge cai liao ,geng jin yi bu di sheng ji guang cui hua xi qing huo xing 。tong guo shang shu duo chong biao zheng shou duan dui CNNS/rGO/BCNDsjin hang xiang guan biao zheng 。jie guo biao ming ,ji guang cui hua xi qing huo xing ke da dao 2036.1μmol·g-1·h-1,shi CNNS(176.9μmol·g-1·h-1)de 11.5bei ,shi CNNS/0.2 wt%rGO(270.1μmol·g-1·h-1)de 7.5bei ,shi CNNS/(12 mL)BCNDs(1145.5μmol·g-1·h-1)de 1.7bei 。re yang hua bao li hou de g-C3N4(166.3 m2·g-1)de bi biao mian ji xiang dui yu kuai zhuang g-C3N4(20.4 m2·g-1)di gao le 8.2bei 。CNNSde bi biao mian ji zeng da hou ,ke yi xian zhe su duan dian he qian yi lu jing ,yi zhi dian he chong zu ,geng jin yi bu di sheng guang cui hua xi qing huo xing 。
论文参考文献
论文详细介绍
论文作者分别是来自郑州大学的赵静黎,发表于刊物郑州大学2019-07-09论文,是一篇关于还原氧化石墨烯论文,硼掺杂的点论文,光催化析氢论文,郑州大学2019-07-09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,资料来自郑州大学2019-07-09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:还原氧化石墨烯论文; 硼掺杂的点论文; 光催化析氢论文; 郑州大学2019-07-09论文;