ZIFs基三維碳納米材料的制備及在環(huán)境電化學(xué)中的應(yīng)用
發(fā)布時(shí)間：2018-11-01 20:40
【摘要】：為了促進(jìn)可持續(xù)發(fā)展,綠色、可再生的燃料電池、超級電容器等清潔能源和過氧化氫傳感器等環(huán)境監(jiān)測技術(shù)正不斷被開發(fā)出來,以滿足日益增長的能源與環(huán)境需求。其中,如何針對這些新興的能源與環(huán)境技術(shù)開發(fā)出恰當(dāng)?shù)碾姌O材料,進(jìn)一步縮小器件體積、并同時(shí)提高其能量轉(zhuǎn)化效率和精確度是目前亟待解決的問題。本論文以類沸石咪唑結(jié)構(gòu)(ZIFs)這種新型納米材料為基礎(chǔ),設(shè)計(jì)并開發(fā)了一系列碳納米電極。深入探究了電極材料的形貌和結(jié)構(gòu),研究二者與電化學(xué)性能之間的關(guān)系,深層次地闡明了ZIFs基碳納米材料在能源與環(huán)境中的應(yīng)用潛力。具體有以下三個(gè)方面:(1)通過引入含鎳配位化合物的方式,設(shè)計(jì)并合成了基于ZIF-67的Co、Ni、N三元摻雜碳納米材料。得到的碳納米材料顯示出了珊瑚或海綿狀形貌,將離散的ZIF-67顆粒聚集成一個(gè)整體結(jié)構(gòu),提供了豐富的微孔隙率和高吡啶氮含量,并形成了 Co-N-C和Ni-N-C鍵作為多重活性位點(diǎn)。作為電極在酸性和堿性條件下的氧氣還原反應(yīng)(ORR)和氧氣析出反應(yīng)(OER)均顯示出了非常強(qiáng)的活性,EOER和EORR之間的過電位差值為0.78 V,ORR和OER的雙功能性能超過了商業(yè)化Pt/C和大部分非貴金屬催化劑。(2)通過ZIF-67與石墨烯復(fù)合形成三明治結(jié)構(gòu),以提高電子傳輸速率,并在此基礎(chǔ)上,通過化學(xué)氣相沉積(CVD)的方法摻雜硼原子,形成BNC鍵和Co2B鍵作為新活性位點(diǎn),并使吡啶氮含量上升。將此電極材料用于H202檢測,可以使線性響應(yīng)范圍提升至0.5 μM～60 mM,檢測限低至0.19μM,響應(yīng)時(shí)間約為3 s,性能優(yōu)于目前報(bào)道的同類材料。檢測范圍在低濃度區(qū)(0.5 mM)和高濃度區(qū)(0.5 mM)的線性相關(guān)系數(shù)均能達(dá)到0.999以上。(3)通過將ZIFs引入氣凝膠中并碳化的方式,設(shè)計(jì)并合成了 ZIF-7復(fù)合纖維素和殼聚糖氣凝膠材料,碳化后得到的材料顯示出三明治和串珠狀的微觀結(jié)構(gòu)。這種ZIF-7與氣凝膠纖維的復(fù)合,可以加快電子在一維或二維方向的傳輸,使內(nèi)阻減小。該材料作為電極材料應(yīng)用于超級電容器中分別顯示出150.4F·g-1和173.1F·g-1的比電容和小于2Ω的電荷轉(zhuǎn)移電阻,遠(yuǎn)高于碳化原料作為電極的比電容,是理想的超級電容器電極材料。
[Abstract]:In order to promote sustainable development, green, renewable fuel cells, supercapacitors and other clean energy and hydrogen peroxide sensors and other environmental monitoring technologies are being developed to meet the increasing energy and environmental needs. Among them, how to develop appropriate electrode materials for these new energy and environmental technologies, further reduce the volume of devices, and improve their energy conversion efficiency and accuracy are the problems to be solved. In this paper, a series of carbon nanoelectrodes were designed and developed on the basis of zeolite imidazole-like structure (ZIFs). The morphology and structure of electrode materials and the relationship between them and electrochemical properties were studied. The application potential of ZIFs based carbon nanomaterials in energy and environment was expounded. There are three aspects as follows: (1) Co,Ni,N ternary doped carbon nanomaterials based on ZIF-67 were designed and synthesized by introducing nickel coordination compounds. The obtained carbon nanocomposites exhibit coral or spongy morphology, aggregating discrete ZIF-67 particles into a single structure, providing rich microporosity and high pyridine nitrogen content. Co-N-C and Ni-N-C bonds were formed as multiple active sites. The oxygen reduction reaction (ORR) and the oxygen precipitate reaction (OER) at acidic and alkaline conditions showed very strong activity. The overpotential difference between EOER and EORR was 0.78 V, and the overpotential difference between EOER and EORR was 0.78 V, and the overpotential difference between EOER and EORR was 0.78 V. The bifunctional properties of ORR and OER are superior to those of commercial Pt/C and most non-noble metal catalysts. (2) the sandwich structure is formed by combining ZIF-67 with graphene to improve the electron transport rate. Boron atoms were doped by chemical vapor deposition (CVD) to form BNC bond and Co2B bond as new active sites, and the content of pyridine nitrogen increased. The linear response range can be raised to 0. 19 渭 m and the response time is about 3 s. The linear response range of the electrode material is better than that of the similar materials reported in this paper. The linear response range of the electrode can be increased to 0. 19 渭 M and the response time is about 3 s. The linear correlation coefficients in the low concentration region (0. 5 mM) and the high concentration region (0. 5 mM) can reach more than 0.999. (3) by introducing ZIFs into aerogels and carbonizing, ZIF-7 composite cellulose and chitosan aerogel materials were designed and synthesized. The carbonized materials showed sandwich and beaded microstructure. The combination of ZIF-7 and aerogel fiber can accelerate the transmission of electrons in one or two dimensional direction and reduce the internal resistance. The specific capacitance of 150.4 F g -1 and 173.1 F g -1 and charge transfer resistance of less than 2 惟 are shown in the supercapacitors as electrode materials, which are much higher than the specific capacitance of carbonized raw materials as electrodes. It is an ideal electrode material for supercapacitor.
【學(xué)位授予單位】：中國科學(xué)院大學(xué)(中國科學(xué)院過程工程研究所)
【學(xué)位級別】：碩士
【學(xué)位授予年份】：2017
【分類號】：TB383.1;O613.71
，
本文編號：2305043
[Abstract]:In order to promote sustainable development, green, renewable fuel cells, supercapacitors and other clean energy and hydrogen peroxide sensors and other environmental monitoring technologies are being developed to meet the increasing energy and environmental needs. Among them, how to develop appropriate electrode materials for these new energy and environmental technologies, further reduce the volume of devices, and improve their energy conversion efficiency and accuracy are the problems to be solved. In this paper, a series of carbon nanoelectrodes were designed and developed on the basis of zeolite imidazole-like structure (ZIFs). The morphology and structure of electrode materials and the relationship between them and electrochemical properties were studied. The application potential of ZIFs based carbon nanomaterials in energy and environment was expounded. There are three aspects as follows: (1) Co,Ni,N ternary doped carbon nanomaterials based on ZIF-67 were designed and synthesized by introducing nickel coordination compounds. The obtained carbon nanocomposites exhibit coral or spongy morphology, aggregating discrete ZIF-67 particles into a single structure, providing rich microporosity and high pyridine nitrogen content. Co-N-C and Ni-N-C bonds were formed as multiple active sites. The oxygen reduction reaction (ORR) and the oxygen precipitate reaction (OER) at acidic and alkaline conditions showed very strong activity. The overpotential difference between EOER and EORR was 0.78 V, and the overpotential difference between EOER and EORR was 0.78 V, and the overpotential difference between EOER and EORR was 0.78 V. The bifunctional properties of ORR and OER are superior to those of commercial Pt/C and most non-noble metal catalysts. (2) the sandwich structure is formed by combining ZIF-67 with graphene to improve the electron transport rate. Boron atoms were doped by chemical vapor deposition (CVD) to form BNC bond and Co2B bond as new active sites, and the content of pyridine nitrogen increased. The linear response range can be raised to 0. 19 渭 m and the response time is about 3 s. The linear response range of the electrode material is better than that of the similar materials reported in this paper. The linear response range of the electrode can be increased to 0. 19 渭 M and the response time is about 3 s. The linear correlation coefficients in the low concentration region (0. 5 mM) and the high concentration region (0. 5 mM) can reach more than 0.999. (3) by introducing ZIFs into aerogels and carbonizing, ZIF-7 composite cellulose and chitosan aerogel materials were designed and synthesized. The carbonized materials showed sandwich and beaded microstructure. The combination of ZIF-7 and aerogel fiber can accelerate the transmission of electrons in one or two dimensional direction and reduce the internal resistance. The specific capacitance of 150.4 F g -1 and 173.1 F g -1 and charge transfer resistance of less than 2 惟 are shown in the supercapacitors as electrode materials, which are much higher than the specific capacitance of carbonized raw materials as electrodes. It is an ideal electrode material for supercapacitor.
【學(xué)位授予單位】：中國科學(xué)院大學(xué)(中國科學(xué)院過程工程研究所)
【學(xué)位級別】：碩士
【學(xué)位授予年份】：2017
【分類號】：TB383.1;O613.71
，
本文編號：2305043
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