%0 Journal Article
%T <br>
%A 刘忠范
%A 史刘嵘
%A 彭海琳
%A 杨皓
%A 王可心
%A 王铭展
%J 物理化学学报
%D 2019
%R 10.3866/PKU.WHXB201805032
%X 三维石墨烯(3DG)被广泛研究用于能量存储和转换器件中的导电框架材料。化学气相沉积(CVD)是制备品质三维石墨烯的重要方法，其中选择合适的模板材料对于调控石墨烯形貌和成本至关重要。在此，本文使用牛骨灰这一廉价易得的生物废弃物作为CVD模板，制备了高品质三维石墨烯。这种三维石墨烯表现出“双连续”的微观结构，即石墨烯框架及其空隙均是连续的，因而可以作为导电框架材料用于电化学储能器件。我们将硫均匀负载于三维石墨烯作为高性能锂-硫电池的正极材料，其在高倍率(2C)下具有约550 mAh·g-1的高比容量。此外，将牛骨灰模板蚀刻后所得溶液可作为原料用于磷酸生产，实现了高的原子利用率。这一工作将石墨烯制备与成熟的磷化工产业结合，发展了一种低成本、高原子经济性地制备三维石墨烯的新途径。<br>As a new 2D material with excellent chemical stability, good electric conductivity, and high specific surface area, graphene has been widely used in energy storage and conversion devices. However, 2D graphene layers are easily stacked, which may significantly reduce the surface area and degrade the excellent electrical properties of graphene. To avoid this, one of the most effective methods is to construct 3D graphene (3DG) with specific porous microstructures. Chemical vapor deposition (CVD) is an important method for the synthesis of high-quality 3DG, where templates play a defining role in controlling the structure and cost of 3DG. Metallic materials with 3D microstructures, such as nickel foam, have proven to be useful as substrates for the growth of high-quality 3DG. However, metal substrates are usually expensive, and the pickling solution generated after etching may cause environmental problems. Therefore, non-metallic substrate materials with lower costs have been investigated for the preparation of 3DG. Herein, we developed a novel template material, mammal bone ashes, for the CVD preparation of 3DG. Mammal bone ash is an inexpensive and abundant biomass hydroxyapatite. During the high-temperature CVD reaction, the bone ash powders were slightly sintered to form a continuous porous structure with graphene coating. The morphology of 3DG is inherited from the microstructure of bone ash templates. After removing the bone ash template with hydrochloric acid, the template-grown 3DG was obtained with a unique bicontinuous structure, i.e. both the graphene framework and the void space were continuous. In addition, the pickling solution of the bone ash templates after etching was exactly the same as that for the raw materials for the production of phosphoric acid to achieve high atom utilization. We further optimized the graphitization degrees, layer number, and porous morphology of 3DGs. The microstructure evolution of 3DG is highly relevant to the layer thickness and uniformity of graphene layers. A short growth time would lead to a non-uniform and thin layer of graphene, which is not able to support a complex 3D porous structure. In contrast, a uniform graphene layer with proper thickness is capable of forming a
%U http://www.whxb.pku.edu.cn/CN/Y2019/V35/I10/1112