哈尔滨工业大学理学硕士学位论文
Abstract
Increasing environmental awareness and energy demand have driven the inevitable shift from traditional fossil fuels to clean renewable energy sources. However,the development of new energy with high energy density,such as regenerative fuel cells and rechargeable metal air batteries,is seriously hindered by the lack of electrocatalysts with ideal oxygen reduction reaction(ORR)and oxygen precipitation reaction(OER)catalytic kinetics..Existing catalysts exhibit a large overpotential,resulting in their relatively low energy density and high energy costs during charging.In addition,the widespread use of precious metal electrocatalysts commonly used in practical applications is obviously limited by high costs and poor durability.Therefore,the research and development of non-precious metal-based electrocatalysts came into being.Among them,non-metallic carbonaceous materials have caused great concern for their high theoretical activity,wide source,low cost, environmental protection,and long-term durability as dual-functional ORR and OER electrocatalysts.
In this dissertation,monolayer graphene nanosheets and vertical oriented graphene were prepared by chemical vapor deposition,micro mechanical ablation and plasma enhanced vapor deposition.Chlorine photochlorination and UV assisted metal chloride decomposition and chlorination were used to design structural defects and covalent C-Cl bonds through the sp2-to-sp3hybridization transition in graphene. It was confirmed by X-ray photoelectron spectroscopy(XPS)that graphene with a Cl coverage of18atom%was successfully prepared,and the changes of D,G,and 2D peaks were monitored by Raman spectroscopy after irradiation.The mobility of the graphene chloride field effect transistor decreased from730.4cm2/(V·s)to66.1 cm2/(V·s),showing obvious semiconductor properties and P-type doping characteristics.Raman spectroscopy indicates that defects and C-Cl bonds are closely related to the irradiation time,thus structural defects and compositions can be designed accordingly.
Since the generation of active sites and the fast performance of ion and electron transmission,graphene chloride has met the requirements of electrocatalytic reaction characteristics.Measurement of chlorinated vertically-oriented graphene as an excellent bifunctional ORR and OER self-supporting electrode using a standard three-electrode system electrochemical workstation,showing an overpotential of 370mV for OER at10mA/cm2,Tafel slope is41mV/dec,which exceeds commercial Ir/C.At the same time,the ORR reduction peak appears at0.776V vs. RHE,resulting in a more positive oxygen reduction voltage and a greater limited
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哈尔滨工业大学理学硕士学位论文
intrinsic graphene.In terms of durability,the current density loss of the graphene chloride electrode after a12-hour chronoamperometry test was only4.2%,superior to commercial Ir/C material.
In this dissertation,two general chlorination methods were developed. Graphene chloride was successfully prepared by giving carbon-rich materials rich defects and polarized carbon as active sites.The excellent bifunctional ORR and OER electrocatalytic activities make graphene chloride materials aas a high application value in fuel cells and metal-air batteries.
Keywords:Photochlorination,Vertically-Oriented Graphene,Defect Engineering, Oxygen Reduction Reaction,Oxygen Evolution Reaction
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哈尔滨工业大学理学硕士学位论文
目录
摘要...............................................................................................................................I ABSTRACT...................................................................................................................III 第1章绪论. (1)
1.1课题的背景及研究目的和意义 (1)
1.2石墨烯的制备与卤化修饰方法 (2)
1.2.1石墨烯的主要制备方法 (2)
1.2.2石墨烯的功能结构 (4)
1.2.3石墨烯的卤素掺杂方法研究进展 (5)
1.3非金属杂原子掺杂石墨烯OER/ORR研究现状 (8)
1.3.1非金属氧还原电催化剂研究进展 (9)
1.3.2非金属析氧电催化剂研究进展 (9)
1.3.3非金属双功能电催化剂研究进展 (10)
1.4本论文主要研究内容 (11)
第2章实验材料及测试方法 (12)
2.2化学仪器与设备 (13)
2.3材料的表征方法 (13)
2.3.1光学形貌分析 (14)
2.3.2拉曼光谱分析 (14)
2.3.3扫描电子显微镜分析 (14)
2.3.4透射电子显微镜分析 (14)
2.3.5原子力显微镜分析 (15)
2.3.6X射线衍射图谱分析 (15)
2.3.7电学性能测试 (15)
2.3.8电化学测试 (15)
第3章氯气光氯化石墨烯的制备及电化学性能研究 (16)
3.1引言 (16)
3.2石墨烯单晶和垂直石墨烯的生长及光氯化 (16)
3.2.1单层石墨烯的CVD生长制备 (16)
3.2.2碳布上垂直石墨烯的生长制备 (16)
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哈尔滨工业大学理学硕士学位论文
3.3氯化石墨烯的表征 (18)
3.3.1氯化石墨烯的形貌 (18)
3.3.2氯化石墨烯的结构组成 (20)
3.3.3氯化石墨烯的拉曼表征 (21)
3.4氯化石墨烯电子输运性能 (22)
3.5氯化垂直石墨烯的电催化性能 (25)
3.5.1氯化垂直石墨烯的OER (27)
3.5.2氯化垂直石墨烯的ORR (29)
3.5.3OER和ORR机理分析 (31)
3.6本章小结 (35)
第4章金属氯化物辅助制备氯化石墨烯及其电化学性能研究 (36)
4.1引言 (36)
4.2金属氯化物辅助光氯化石墨烯制备方法 (36)
4.3氯化石墨烯的表征 (37)
4.3.1氯化垂直石墨烯的ORR (37)
4.3.2氯化石墨烯的结构组成 (37)
4.3.3氯化石墨烯的拉曼表征 (39)
4.4氯化石墨烯电子输运性能 (42)
4.5氯化垂直石墨烯的电催化性能 (44)
4.5.1负载金属盐的氯化垂直石墨烯的电化学性能 (44)
4.5.2氯化垂直石墨烯的电化学性能 (50)
4.6本章小结 (55)
结论 (56)
参考文献 (57)
攻读学位期间发表的学术论文及申请专利 (64)
哈尔滨工业大学学位论文原创性声明和使用权限 (65)
致谢 (66)
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