可见光响应的三维石墨烯/氧化钴复合催化剂及其光解水制氢性能

3D graphene/CoO and the photocatalytic properties for hydrogen evolution from water splitting under visible light irradiation

  • 摘要: 以新型二维材料氧化石墨烯和金属有机框架化合物ZIF-67为前驱体,通过溶剂热反应和高温焙烧过程,制备了一种三维交联石墨烯负载CoO纳米粒子(3D G/CoO)的复合催化剂材料。XRD、XPS、紫外可见漫反射、SEM和TEM等结构和形貌分析结果表明:平均粒径约为34.5 nm的CoO粒子均匀负载在三维交联石墨烯体相骨架中。三维石墨烯特有的光致热电子发射性能及两种材料间的协同作用,赋予了复合材料优异的光催化分解水制氢性能。在300 W氙灯照射下,催化分解水制氢速率为10.1 mmol·gcat−1·h−1;在520 nm波长可见光照射下,获得了7.77%的表观量子效率。催化剂循环使用5次,活性保持率为88%。此高性能可见光响应的三维复合催化剂材料的研究,对光催化领域中新型高效催化剂的开发和应用具有重要意义。

     

    Abstract: A three-dimensional cross-linked graphene (G) supported CoO nano composite (3D G/CoO) was prepared by solvothermal reaction followed by annealing at high temperature using graphene oxide and metal organic framework (ZIF-67) as precursors. The structures and morphologies of 3D G/CoO were characterized by XRD, XPS, UV-vis diffuse reflectance spectrum, SEM and TEM. The results show that CoO particles with an average particle size of ~34.5 nm are uniformly loaded on the graphene sheets. Based on the unique hot electron emission properties of 3D G, as well as the synergetic effect between the two components, 3D G/CoO nano composites exhibit excellent photocatalytic properties for hydrogen evolution from water splitting under the irradiation. Under 300 W Xenon lamp, the hydrogen production rate is 10.1 mmol·gcat−1·h−1. The apparent quantum efficiency of 7.77% is obtained at 520 nm visible light. After recycling for 5 times, the hydrogen production rate is maintained at 88%. This high-performance visible light responsive 3D photocatalyst is of great significance to the development of highly efficient catalysts in the field of photocatalysis.

     

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