张云霄:类石墨相氮化碳上非铂析氢中心的构建及其光催化产氢性能的研究论文

张云霄:类石墨相氮化碳上非铂析氢中心的构建及其光催化产氢性能的研究论文

本文主要研究内容

作者张云霄(2019)在《类石墨相氮化碳上非铂析氢中心的构建及其光催化产氢性能的研究》一文中研究指出:用清洁的能源代替不可再生的化石能源是当今社会人们解决环境污染和能源危机问题的有效措施。与其它的太阳能燃料相比,氢能具有易于储存、环境友好、含能量高等优点。科研工作者主要致力于寻找高效、稳定、价格低廉的光催化剂,以期实现光催化制氢的工业化应用。类石墨相氮化碳(g-C3N4)是一种二维非金属半导体材料,具有合适的禁带宽度、优异的化学稳定性和制备简单等优点。但是,g-C3N4的光催化活性仍然较低。科研工作者常采用金属或非金属元素掺杂、与其它半导体材料构建异质结、调控微观纳米结构等手段对g-C3N4进行改性,提高g-C3N4对可见光的利用率、光生电子和光生空穴的分离效率以及扩大比表面积,以提高g-C3N4的光催化产氢活性。然而,以上改性手段通常需要加入贵金属如铂作助催化剂,降低析氢反应的过电势,促进氢气的逸出。因此,为了降低g-C3N4在光催化反应中所需的成本,本文在g-C3N4上构建了金属硫化物和过渡金属配合物析氢中心,制备出四种不同的非贵金属复合催化剂用于光催化产氢。主要内容如下:1.碳纳米管(CNTs)在硫化镍(NiS)、硫化钼(MoS2)协同作用下修饰g-C3N4纳米片通过高温热缩聚和水热处理的方法制备了CNTs、NiS和MoS2修饰的g-C3N4纳米片,得到NiS-MoS2/CNTs/CN复合催化剂。采用不同的测试手段表征复合催化剂的微观形貌和光学性质,并进一步研究它们的光催化产氢活性。在光催化产氢的过程中,NiS和MoS2表现出优异的协同效应。与MoS2/CN相比,引入NiS和CNTs可以显著地提高催化剂的可见光吸收范围和光生电子和光生空穴的分离效率。在可见光照射下,不加入贵金属时,NiS-MoS2/CNTs/CN的最优产氢速率达到309.9μmol·h-1·g-1。2.钴配合物和氨基官能化的碳量子点修饰g-C3N4纳米片通过酰胺键耦合钴配合物(Co(dcbpy)2(NCS)2,dcbpy=4,4’-二羧基-2,2’-联吡啶)与氨基官能化的碳量子点(CQDs)或类石墨相氮化碳纳米片(CN),制备得到了一种可以实现太阳能-氢能转化的三元复合光催化剂Co(dcbpy)2(NCS)2/CQDs/CN。分子内酰胺键促进了Co(dcbpy)2(NCS)和CQDs/CN的结合,提高了Co(dcbpy)2(NCS)2在CN骨架上的分散性,从而增强了光生载流子的迁移和对可见光的吸收。在可见光照射下,单一的CN没有光催化活性。而Co(dcbpy)2(NCS)2/CQDs/CN的最优产氢活性达到295.9μmol·h-1·g-1,连续测试四个循环之后,产氢速率基本没有发生衰减。在λ=450 nm的单色光照射下,3Co(dcbpy)2(NCS)2/CQDs/CN的光催化产氢速率达到75.02μmol·h-1·g-1,AQE达到0.71%。3.镍-席夫碱配合物和氧化镍纳米粒子修饰g-C3N4纳米片通过简单的化学反应制备得到两个四配位的钴(CoLa)和镍(NiLa)席夫碱配合物用于电催化还原质子或水制取氢气。在-1.45 V vs.Ag/AgCl的电压下,pH=7.0的缓冲溶液中,CoLa和NiLa的TOF值分别达到738.23 h-1和1331.23 h-1。参照NiLa的结构,制备得到一种新型的镍-席夫碱配合物(NiLb)。把类石墨相氮化碳(CN)、镍-席夫碱配合物(NiLb)和氧化镍纳米粒子(NiOx)通过简单的有机反应制备得到一种新型的非贵金属复合催化剂NiLb/NiOx/CN。利用双分子亲核取代反应,通过化学键使NiLb和CN结合在一起,得到负载量较高和分散性较好的NiLb/CN催化剂。在NiLb/CN体系中引入空穴传输材料-NiOx,促进光生电子和光生空穴的分离,以期提高催化剂的光催化产氢活性。在可见光照射下,NiLb/CN的最优产氢活性达到303.3μmol·h-1·g-1,而NiLb/NiOx/CN的最优产氢活性达到524.1μmol·h-1·g-1。在λ=450 nm的单色光照射下,4NiLb/NiOx/CN的AQE达到1.46%。4.镍配合物修饰面内掺杂苯环的g-C3N4纳米片通过胺双(苯酚)配体和金属盐制备得到一种新的双核钴(III)[Lc2Co2Cl2]配合物。该配合物在887.6 mV的过电势下,TOF值达到844.63 h-1,具有较为优异的电催化性质。参照Lc2Co2Cl2的合成过程,制备得到一种新型的镍-席夫碱配合物(NiLd)。采用尿素和4,4’-二氨基联苯砜(DAPS)高温热缩聚制备得到面内掺杂苯环的g-C3N4纳米片(CN-DAPS)。通过分子内化学键使镍配合物(NiLd)和CN-DAPS结合在一起,制备得到一种新型、高效的可见光催化剂NiLd/CN-DAPS。在g-C3N4纳米片上面内掺杂苯环拓宽了CN-DAPS的π共轭体系、促进了光生电子和光生空穴的分离以及提高了CN-DAPS对可见光的吸收。NiLd和CN-DAPS之间的分子内化学键促进了光生电子由CN-DAPS传输给NiLd,同时也提高了NiLd在CN-DAPS骨架上的分散性。在可见光照射下,NiLd/CN的最优产氢活性达到613.4μmol·h-1·g-1。在λ=450 nm的单色光照射下,3NiLd/CN-DAPS的AQE达到2.15%。

Abstract

yong qing jie de neng yuan dai ti bu ke zai sheng de hua dan neng yuan shi dang jin she hui ren men jie jue huan jing wu ran he neng yuan wei ji wen ti de you xiao cuo shi 。yu ji ta de tai yang neng ran liao xiang bi ,qing neng ju you yi yu chu cun 、huan jing you hao 、han neng liang gao deng you dian 。ke yan gong zuo zhe zhu yao zhi li yu xun zhao gao xiao 、wen ding 、jia ge di lian de guang cui hua ji ,yi ji shi xian guang cui hua zhi qing de gong ye hua ying yong 。lei dan mo xiang dan hua tan (g-C3N4)shi yi chong er wei fei jin shu ban dao ti cai liao ,ju you ge kuo de jin dai kuan du 、you yi de hua xue wen ding xing he zhi bei jian chan deng you dian 。dan shi ,g-C3N4de guang cui hua huo xing reng ran jiao di 。ke yan gong zuo zhe chang cai yong jin shu huo fei jin shu yuan su can za 、yu ji ta ban dao ti cai liao gou jian yi zhi jie 、diao kong wei guan na mi jie gou deng shou duan dui g-C3N4jin hang gai xing ,di gao g-C3N4dui ke jian guang de li yong lv 、guang sheng dian zi he guang sheng kong xue de fen li xiao lv yi ji kuo da bi biao mian ji ,yi di gao g-C3N4de guang cui hua chan qing huo xing 。ran er ,yi shang gai xing shou duan tong chang xu yao jia ru gui jin shu ru bo zuo zhu cui hua ji ,jiang di xi qing fan ying de guo dian shi ,cu jin qing qi de yi chu 。yin ci ,wei le jiang di g-C3N4zai guang cui hua fan ying zhong suo xu de cheng ben ,ben wen zai g-C3N4shang gou jian le jin shu liu hua wu he guo du jin shu pei ge wu xi qing zhong xin ,zhi bei chu si chong bu tong de fei gui jin shu fu ge cui hua ji yong yu guang cui hua chan qing 。zhu yao nei rong ru xia :1.tan na mi guan (CNTs)zai liu hua nie (NiS)、liu hua mu (MoS2)xie tong zuo yong xia xiu shi g-C3N4na mi pian tong guo gao wen re su ju he shui re chu li de fang fa zhi bei le CNTs、NiShe MoS2xiu shi de g-C3N4na mi pian ,de dao NiS-MoS2/CNTs/CNfu ge cui hua ji 。cai yong bu tong de ce shi shou duan biao zheng fu ge cui hua ji de wei guan xing mao he guang xue xing zhi ,bing jin yi bu yan jiu ta men de guang cui hua chan qing huo xing 。zai guang cui hua chan qing de guo cheng zhong ,NiShe MoS2biao xian chu you yi de xie tong xiao ying 。yu MoS2/CNxiang bi ,yin ru NiShe CNTske yi xian zhe de di gao cui hua ji de ke jian guang xi shou fan wei he guang sheng dian zi he guang sheng kong xue de fen li xiao lv 。zai ke jian guang zhao she xia ,bu jia ru gui jin shu shi ,NiS-MoS2/CNTs/CNde zui you chan qing su lv da dao 309.9μmol·h-1·g-1。2.gu pei ge wu he an ji guan neng hua de tan liang zi dian xiu shi g-C3N4na mi pian tong guo xian an jian ou ge gu pei ge wu (Co(dcbpy)2(NCS)2,dcbpy=4,4’-er suo ji -2,2’-lian bi ding )yu an ji guan neng hua de tan liang zi dian (CQDs)huo lei dan mo xiang dan hua tan na mi pian (CN),zhi bei de dao le yi chong ke yi shi xian tai yang neng -qing neng zhuai hua de san yuan fu ge guang cui hua ji Co(dcbpy)2(NCS)2/CQDs/CN。fen zi nei xian an jian cu jin le Co(dcbpy)2(NCS)he CQDs/CNde jie ge ,di gao le Co(dcbpy)2(NCS)2zai CNgu jia shang de fen san xing ,cong er zeng jiang le guang sheng zai liu zi de qian yi he dui ke jian guang de xi shou 。zai ke jian guang zhao she xia ,chan yi de CNmei you guang cui hua huo xing 。er Co(dcbpy)2(NCS)2/CQDs/CNde zui you chan qing huo xing da dao 295.9μmol·h-1·g-1,lian xu ce shi si ge xun huan zhi hou ,chan qing su lv ji ben mei you fa sheng cui jian 。zai λ=450 nmde chan se guang zhao she xia ,3Co(dcbpy)2(NCS)2/CQDs/CNde guang cui hua chan qing su lv da dao 75.02μmol·h-1·g-1,AQEda dao 0.71%。3.nie -xi fu jian pei ge wu he yang hua nie na mi li zi xiu shi g-C3N4na mi pian tong guo jian chan de hua xue fan ying zhi bei de dao liang ge si pei wei de gu (CoLa)he nie (NiLa)xi fu jian pei ge wu yong yu dian cui hua hai yuan zhi zi huo shui zhi qu qing qi 。zai -1.45 V vs.Ag/AgClde dian ya xia ,pH=7.0de huan chong rong ye zhong ,CoLahe NiLade TOFzhi fen bie da dao 738.23 h-1he 1331.23 h-1。can zhao NiLade jie gou ,zhi bei de dao yi chong xin xing de nie -xi fu jian pei ge wu (NiLb)。ba lei dan mo xiang dan hua tan (CN)、nie -xi fu jian pei ge wu (NiLb)he yang hua nie na mi li zi (NiOx)tong guo jian chan de you ji fan ying zhi bei de dao yi chong xin xing de fei gui jin shu fu ge cui hua ji NiLb/NiOx/CN。li yong shuang fen zi qin he qu dai fan ying ,tong guo hua xue jian shi NiLbhe CNjie ge zai yi qi ,de dao fu zai liang jiao gao he fen san xing jiao hao de NiLb/CNcui hua ji 。zai NiLb/CNti ji zhong yin ru kong xue chuan shu cai liao -NiOx,cu jin guang sheng dian zi he guang sheng kong xue de fen li ,yi ji di gao cui hua ji de guang cui hua chan qing huo xing 。zai ke jian guang zhao she xia ,NiLb/CNde zui you chan qing huo xing da dao 303.3μmol·h-1·g-1,er NiLb/NiOx/CNde zui you chan qing huo xing da dao 524.1μmol·h-1·g-1。zai λ=450 nmde chan se guang zhao she xia ,4NiLb/NiOx/CNde AQEda dao 1.46%。4.nie pei ge wu xiu shi mian nei can za ben huan de g-C3N4na mi pian tong guo an shuang (ben fen )pei ti he jin shu yan zhi bei de dao yi chong xin de shuang he gu (III)[Lc2Co2Cl2]pei ge wu 。gai pei ge wu zai 887.6 mVde guo dian shi xia ,TOFzhi da dao 844.63 h-1,ju you jiao wei you yi de dian cui hua xing zhi 。can zhao Lc2Co2Cl2de ge cheng guo cheng ,zhi bei de dao yi chong xin xing de nie -xi fu jian pei ge wu (NiLd)。cai yong niao su he 4,4’-er an ji lian ben feng (DAPS)gao wen re su ju zhi bei de dao mian nei can za ben huan de g-C3N4na mi pian (CN-DAPS)。tong guo fen zi nei hua xue jian shi nie pei ge wu (NiLd)he CN-DAPSjie ge zai yi qi ,zhi bei de dao yi chong xin xing 、gao xiao de ke jian guang cui hua ji NiLd/CN-DAPS。zai g-C3N4na mi pian shang mian nei can za ben huan ta kuan le CN-DAPSde πgong e ti ji 、cu jin le guang sheng dian zi he guang sheng kong xue de fen li yi ji di gao le CN-DAPSdui ke jian guang de xi shou 。NiLdhe CN-DAPSzhi jian de fen zi nei hua xue jian cu jin le guang sheng dian zi you CN-DAPSchuan shu gei NiLd,tong shi ye di gao le NiLdzai CN-DAPSgu jia shang de fen san xing 。zai ke jian guang zhao she xia ,NiLd/CNde zui you chan qing huo xing da dao 613.4μmol·h-1·g-1。zai λ=450 nmde chan se guang zhao she xia ,3NiLd/CN-DAPSde AQEda dao 2.15%。

论文参考文献

论文详细介绍

论文作者分别是来自华南理工大学的张云霄,发表于刊物华南理工大学2019-10-23论文,是一篇关于类石墨相氮化碳论文,过渡金属配合物论文,共价结合论文,光催化制氢论文,华南理工大学2019-10-23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,资料来自华南理工大学2019-10-23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。

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张云霄:类石墨相氮化碳上非铂析氢中心的构建及其光催化产氢性能的研究论文
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