中文摘要：

超声分散氧化石墨和聚苯乙烯微球于去离子水形成稳定分散液,加入氨水和水合肼还原氧化石墨得到包覆石墨烯纳米片的聚苯乙烯微球,经6 mol·L-1KOH碱蚀和甲苯洗脱聚苯乙烯制备3D石墨烯.将3D石墨烯超声分散于去离子水,然后分别以硝酸镍、硝酸铝和尿素为镍源、铝源和碱源化合物水热合成3D石墨烯/镍铝层状双金属氢氧化物复合材料.采用红外、拉曼、X射线衍射、扫描电镜、透射电镜和恒电流充-放电测试对材料的结构、形貌及电化学性质进行研究.结果表明,氧化石墨被还原形成有微孔结构的3D石墨烯.镍铝双金属氢氧化物纳米片均匀分散在3D石墨烯孔壁.在1 A·g-1的电流密度下,复合材料电极的比电容为1054.8 F·g-1.当电流密度增加到8 A·g-1时,比电容为628.1 F·g-1.循环充-放电1000次后,比电容仍保持在97%以上,呈示该复合材料具有优异的电化学性能.

英文摘要：

Graphite oxide and polystyrene colloidal microsphere （PS） were dispersed in deionized water with the help of ultrasonic wave to form a stable dispersion. The ammonia and hydrazine were seperately added to the dispersion to reduce graphene oxide and form the PS wrapped with graphene nanosheet. During the process, graphite oxide was chemically reduced by hydrazine in the presence of ammonia to produce positively charged reduced graphite oxide, then the PS colloidal particles negtively charged were wrapped by the graphene nanosheets to form PS/graphene microspheres due to the electrostatic interactions between them. To obtain three-dimensional macroporous graphene nanosheets （3D-GNS）, it was orderly treated by the alkali corrosion in a 6 moloL-1 potassium hydroxide solution and remove of the PS in a toluene. The as-prepared 3D-GNS was well dispersed in deionized water by means of ultrasonic wave and then hydrothermal synthesis method was used to prepare 3D graphene/nickel-aluminium layered double-hydroxide （3D-GNS/Ni-A1 LDH） nanocomposite in a Teflon-lined stainless steel autoclave at 100 ~C for 24 h, in which nickel nitrate, aluminum nitrate and urea were employed as nickel, aluminium and base resources. In this study, IR spectrum, Raman spectroscopy, X-ray diffraction, scanning electron microscopy, transmission electron microscopy and galvanostatic charge-discharge measurement were used to investigate the structure, morpholoy and electrochemical property of the nanocomposite respectively. It was found that the graphite oxide was effectively reduced into the graphene with a 3D micropore structure. Ni-A1 LDH nanoflakes were well dispersed in and out of the wall of 3D-GNS. Moreover, electrochemical performance of the 3D-GNS/Ni-A1 LDH composite was investigated as supercapacitor electrode materials. A 1054.8 Fog-1 of the specific capacitance was found at the current density of 1 Aog-1. When the current density increased up to 8 Aog-1, the specific capacitance remains 628.1 F·g-1. The value was above 97% o