氮掺杂还原石墨烯复合材料的制备及在电催化氧还原中的应用研究

发布时间：2018-12-13 04:50

【摘要】：本研究主要涵盖以下三个部分：第一,以石墨粉为原材料,利用Hummers的改进方法制备氧化石墨烯(GO)。对产物进行扫描电子显微镜(SEM)、透射电子显微镜(TEM)、X线衍射(XRD)、傅里叶红外光谱(FTIR)、紫外可见光谱(UV)和热重分析(TGA)。结果显示：GO的表面有明显的褶皱和蜷曲,且具有大量的含氧官能团,在水中分散性能良好。第二,以GO为主体材料,以铁氰化钾(K3[Fe(CN)6])为铁的金属前驱体和氮源,通过水热法制备出掺氮还原石墨烯/α-Fe2O3纳米盘复合材料(NG/α-Fe2O3)。通过SEM、TEM、XRD、X射线能谱(EDS、X射线光电子能谱(XPS)、激光拉曼FTIR以及TGA对产物进行表征,结果显示：生成了盘状的α-Fe2O3并附载在在掺氮还原石墨烯表面,且N在NG/α-Fe2O3中的掺杂量为6.13 at%。将NG/α-Fe2O3作为电极修饰材料,利用电化学手段对NG/α-Fe2O3的电催化氧还原(ORR)性能进行测试,以10.0 mL 1.5 mg·mL-1K3[Fe(CN)6]和10.0 mL 1.0 mg·mL1-GO为最佳制备条件,测试结果表明：在CV测试条件下,峰电位约为-0.201 V,峰电流密度为62.00 μA·cm2；对O2的电催化还原过程含有2电子和4电子途径；经过7200s的连续扫描后,电流衰减量为26.02%,与20% Pt/C相比更为稳定(20%Pt/C衰减量为35.18%)；此外,该材料还具有优于20% Pt/C的抗甲醇干扰性能,有望在燃料电池阴极催化剂上具备一定的应用价值。第三,以GO、氯化钴(CoCl2·6H2O)、氨水(NH3·H2O)为原料,通过水热法制备出掺氮还原石墨烯／四氧化三钴复合材料(NG/Co3O4)。通过SEM、TEM、XRD、 EDS、XPS、Raman、FTIR、TGA对产物的组成结构进行表征,结果显示：生成的C0304为片层状,生长在掺氮还原石墨烯纳米层上；且N的掺杂量为10.43 at%。通过电化学测试对NG/Co3O4的ORR催化性能表征,结果显示当加入：8.0mL NH3·H2O(含量为25-28%)、10.0 mL 1.5 mg·mL-1的GO和5.0mL 2.0 mg·mL-1的CoCl2寸,该材料具有较好的ORR催化性能。其中,峰电位约为-0.163 V,峰电流密度为73.01 μA·cm-2;氧还原反应主要以4电子途径进行；经过7200 s的连续扫描后,电流衰减量为28.36%,比20%Pt/C稳定；此外,该材料的抗甲醇干扰性能也优于20% Pt/C,在燃料电池阴极催化材料领域将有潜在的应用价值。
[Abstract]:This research mainly covers the following three parts: first, using graphitic powder as raw material, using the improved method of Hummers to prepare graphene oxide (GO). The products were characterized by scanning electron microscope (SEM), (SEM), transmission electron microscope (SEM), (TEM), X line diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), UV-Vis spectrum (UV) and thermogravimetric analysis (TGA). The results show that the surface of GO has obvious folds and curls, and it has a large number of oxygen-containing functional groups, and it has good dispersion in water. Secondly, the nitrogen-doped graphene / 伪-Fe2O3 nanodisk composites (NG/ 伪-Fe2O3) were prepared by hydrothermal method using GO as the main material and potassium ferrocyanide (K3 [Fe (CN) 6] as the iron precursor and nitrogen source). The products were characterized by SEM,TEM,XRD,X X-ray photoelectron spectroscopy (EDS,X) laser Raman FTIR and TGA. The results showed that the 伪 -Fe2O3 was formed on the surface of nitrogen-doped reduced graphene. The doping amount of N in NG/ 伪-Fe2O3 is 6.13 at%.. Using NG/ 伪-Fe2O3 as electrode modification material, the electrocatalytic oxygen reduction (ORR) properties of NG/ 伪-Fe2O3 were measured by electrochemical method. The optimum preparation conditions were 10.0 mL 1.5 mg mL-1K3 [Fe (CN) 6] and 10.0 mL 1.0 mg mL1-GO. The results showed that the peak potential was about-0.201 V under the CV test condition. Peak current density of 62.00 渭 A cm2; After 7200 s of continuous scanning, the current decay is 26.02, which is more stable than 20% Pt/C (20%Pt/C attenuation is 35.18%). In addition, the material is superior to 20% Pt/C in methanol interference resistance, which is expected to have some application value on fuel cell cathode catalyst. Thirdly, nitrogen-doped reduction graphene / cobalt trioxide (NG/Co3O4) composites were prepared by hydrothermal method using GO, cobalt chloride (CoCl2 6H2O) and ammonia water (NH3 H2O) as raw materials. The structure of the product was characterized by SEM,TEM,XRD, EDS,XPS,Raman,FTIR,TGA. The results showed that the formed C0304 was lamellar and grown on the nitrogen-doped reduced graphene nanolayer, and the amount of N doping was 10.43 at%.. The ORR catalytic properties of NG/Co3O4 were characterized by electrochemical test. The results showed that when the addition of 8.0mL NH3 H2O (25-28%), GO of 10.0 mL 1.5 mg mL-1 and CoCl2 inch of 5.0mL 2.0 mg mL-1 were added, The material has good ORR catalytic performance. The peak potential is about-0.163 V, the peak current density is 73.01 渭 A cm-2; oxygen reduction is mainly by 4 electron pathway, after 7200 s continuous scanning, the current attenuation is 28.36 and is more stable than that of 20%Pt/C. In addition, the anti-methanol interference performance of this material is superior to that of 20% Pt/C, in the field of fuel cell cathode catalytic material.
【学位授予单位】：福建师范大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TB33;O643.36

【参考文献】